This is a record of the trials and tribulations of my efforts to firstly resurrect and then restore a 1984 Yamaha RZ500. Its only here because otherwise I will forget what I've done, but you can read it too. The resurrect part was easy, well the first resurrection anyway...
I read about this bike in the aus.motorcycles newsgroup and even though I have my T100 Bonneville on order, I jumped at the chance. I've wanted to own one of these bikes ever since I can remember. Anyway, after some negotiations with its owner I scored it for the bargan (well probably) price of $1000.
The previous owner told me it had a noisy bottom end, but that she had stopped riding it two years previously due to large amounts of smoke comming out of the RH upper pipe. It sounded like a gearbox oil seal needed replacing, so the $1000 wasnt too bad a price. She also said that she had been turning the motor over every so often, but hadnt done it for the last 12 months and now it didnt turn over. Hmmm, thats a bit worrying, but anyway...
I went and picked it up on the 27/07/02, quite a good example, some fairing damage, cracks etc, especially around the LH front blinker where it has been knocked in, but you get that with 15 year old bikes! This is what it looks like (photos not take by me but by the seller) Photos ------->
Didn't touch it until Wednesday 31/07/02, when I started to pull it down a bit. The last owner said that the upper LH cylinder (#3? will find out later), had some moisture in it, so she had sprayed WD-40 in there for me. When I looked in there with a torch it didnt look too nice at all, very red and rusty looking.
The previous owner had said when I picked up the bike, that she was riding it with a friend behind when the smoke had suddenly begun pouring out of the pipe. This sounded like a blown headgasket to me, but she was adamant that it wasnt. Anyway, the bike had been stored fairly well, fuel drained, coolant drained, but unfortunately no oil in the bores. What concerned me was the puddle of rust stained water I found under the bike where it had been parked in my shed. I pulled the bodywork off in search of the source of the water. Eventually I found a trail that lead me back to the exhaust just near the cylinder - it was rusted through. Now a two stroke with a rusted through exhaust is never a good sign. So now I know its had a blown headgasket, which in itself isnt a problem, but this happened 2 years ago...
Thursday 1/8/02, time to take the rear bank cylinder head off. Thankfully on a two stroke this is a peice of piss, and thanks to my workshop manual I have the de-tourqe sequence. Photos of what I found inside to come, but until then, I can best describe it as mud. Quite a bit had crusted onto the cylinder walls, so I wiped out what I could with a rag, then started chipping away a the cylinder with a screwdriver - hey I'm up for a hone (if I'm lucky!) anyway.
After an hour or so I got the worst of it out, and the whole of the crown of the piston exposed. I tried to free it by putting the bike in gear and rocking back and forth, but so far no joy. I also tried to apply some heat to the piston, but I dont have anything with enough flame, so will look into buying something on Saturday.
Saturday 3/8/02, well after much heating of the piston with my new propane burner (and after rebuilding my mates CR250 in the morning), I finally got the piston loose by rocking back and forth in 3rd gear. Pretty happy about that, any hope that I would be able to put it back together and run it were dashed when the piston moved down to reveal the transfer ports. They were full of junk, infact the rubber boot that connects the carb to the cylinder still had liquid in it.
So then it was off with the cylinder, when I cracked the base gasket water poured out - not a good sign. The crankcase was full of water, I will post photos soon, it has to be seen to be believed! The piston got stuck in the last part of the cylinder, but with a bit of twisting back and forth it eventually came free.
Next I blew the crankcase out with compressed air, blew stuff all over the bike, but I got most of it out. Surprisingly the bottom end seems to be ok, I think this is because it wasnt exposed to air. The big end has a bit of a tight spot, but I think it's just got some crap in it (I hope), so with a bit of luck I can flush it out. The whole crankcase (that side anyway) is full of WD-40 and Inox, so hopefully that will help.
On Tuesday 6/8/02 the cylinder is going to an engine shop to have the transfer ports cleaned out as they are full of corrosion and scale, it will also get a hone there. I'll either get it bead blasted or chemically cleaned, then reassembly with the new Wiseco/little ends etc etc. While its all pulled down (and since the reed and stops are rusted in this cylinder), I'm going to replace the steel reeds with Boysen dual stage reeds - damn the expense!
Pulled the radiator out 6/8/02 so I can get it cleaned and pressure tested tomorrow. Now I'm just waiting for the cylinder to be finished and the parts to arrive, then hopefully it will be a smooth assembly then fire it up then off for a spin!
7/8/02
Radiator is aok, pretty much as I expected, so I painted it, might refit it tomorrow if I dont clean the right hand carbs. I did clean the left hand carbs out as the upper carb had had a little moisture through it due to the headgasket blowing. Both carbs came up fine, the mainjets are both 165's, the manual specifies 195's, but I guess it was running ok before... The float levels were perfect, so that was good. Major problem I'm having at the moment is that I can't separate the rubber inlet manifolds from the reed blocks. Some moron has stuck them on with some kind of silocone. Oh well I can still replace the reeds without separating them.
13/8/02
Well finally got the cylinder honed today, the news isnt good! Because the water was in there for so long, its pitted the cylinder walls so deeply that it cant be honed out :-( Since the bike is already bored 2mm oversize at 58mm, I cant get it bored either. So its off to the bike wreckers to track down a replacement cylinder. I forgot to mention that I removed the corrision from the cylinder head and discovered that it had eaten the combustion chamber so badly that it couldnt be used. I tracked down a replacement in Brisbane for $66! Bargain, so hopefully I'll be lucky with the cylinder too.
15/8/02
Decided to replace all the oil injector lines since the bike was so far apart anyway. Glad I did, its a bit of a p@#*k of a job, but it was worth it - the injector lines were very hard. Hopefully I can get some reeds from a guy in America, since it seems like I cant get them in Australia for some reason...
17/8/02
Stripped the R/H bank of carbies - disaster struck! Some butcher has somehow managed to break one of the posts which supports the floats. I cant imagine how you could do this accidentally, the pin which the float pivots on taps out easily so you would really have to be trying (Edit no you don't, it's actually quite easy to break them as the pin can seize in the carb. Older and much RZ500 wiser now!) I'll refit the radiator, but thats all I can really do at the moment. Just have to work on the Lambretta and the IT250 instead!
19/8/02
Getting a replacement cylinder and set of carbs from Brisbane. Cylinder $88, carbs $110 for the pair, not too bad at all. I cant reveal my source incase RZ owners dry up my supply of second hand parts! ;-)
4/9/02
Boyesen Reeds are here from the US - woo hoo! Thanks Jack, you are a champion! Fitted them (2 hrs!), damn you wouldnt want to replace them often.
5/9/02
Carbs turned out to be the wrong side due to my poor description of what it was I wanted. Thought it might not matter, but it does, you cant swap carbs from one side to the other. Anyway, sorted now, carbs cleaned, swapped pilot and main jets (they were different) over. Waiting for cylinder to be rebored.
6/9/02
Picked up the cylinder, bore looks great. Washed out in warm soapy water as per the Wiseco instructions. Weirdest thing I've ever done with motorcycle parts I tell you, but I did get lots of honing grit out of the transfer ports, so its a good idea. Fitted piston into cylinder then onto conrod, no trouble (phew!) Couldnt get some of the studs out of the old cylinder, so will finish it tomorrow (Saturday), four hours is enough for tonight!
7/9/02
Got the rest of the studs out of the old cylinder (thanks Frosty from SuperMoto!) Now reassemble the rest of the bike. Fired up @ around 6pm after only 4 kicks. Just as well, I'd been going since 9:30am and couldnt have kicked much more. Went for a little ride up the lane and back, the front brake lever comes into the bar (pretty much what I was expecting), so better bleed the brakes. Pity I put the bodywork on first, you need to remove the righthand rear panel to do the rear brakes. Lots of nasty rubbish came out, bled the anti dive system while I was at it. Brakes are now quite powerful, although significant pressure is needed on the lever and there isnt much feel. Finish up 9:30pm, very long day since I didnt stop for lunch, but the important thing is its running!!
8/9/02
Because I had to reuse the dodgey old plugs it came with, its only running on three cylinders. Replaced the fuel lines from the tank to the fuel tap (the carb ones were done when the carbs were cleaned up.) Drops to two cylinders, then none - new plugs are desperately required.
9/9/02
New plugs from SuperMoto and its running like a charm, bit too good actually, the front sprocket is spinning inside the chain when the power kicks in. Not really a problem as I'm riding very gently and since its running premix and the oil injector is primed again, its getting way too much oil and conks out. Could be kinked fuel lines as there is no fuel in the filter and I made some of the lines a bit too long. Spent a fustrating 2 hours cursing the person responsible for the design of the fuel lines (and V4's in general) but redid the fuel lines. Fired up ok, but since it was 10pm couldnt really do much - its rather loud. It eventually conked out again in a cloud of two stroke smoke, I think I should have bled the oil pump instead of messing about with premix.
16/9/02
Well, I headed for Inverell today. I got less than 10km before I had to turn around due to a power loss. Up until then the bike was running very sweet, smooth progressive power building strongly from 3000rpm to about 9000 which was as hard as I revved it. I discovered that there was water in the upper left hand exhaust and that all the gearbox oil was gone. So as of Monday (16/9/02) the head is at the engine reconditioners being surface ground while today (17/9/02) I found out that I have to split the crankcases to replace the seals. This is very disheartening as I've already put so much work into this bike and barely ridden it. Oh well, the joys of restoration. I think I will cough up the cash (lots of gaskets = lots of $$$) and make it happen (with some help from my Dad!) While its apart I'll fix first gear as its jumping out. Probably wont be for a couple of weeks though...
25/9/02
The surface griding machine wouldnt hold the head, so I'll just have to lap it flat by hand, no problem. I pulled the motor out last night (damn those things are heavy!), so its off to pull the motor down this weekend. The cost of parts alone is $395 (this is with a fairly hefty discount by the way) so I sure hope to receive some trouble free riding, quite a lot of trouble free riding in fact!
4/3/03
Geez, I havent updated this page for a while! When I pulled the motor apart I discovered that one of the mainbearings had split around its circumference. Decided to rebuild the cranks seeing as one bearing failed and I had the cranks out there anyway, and thats where this rebuild has stalled. Need money for bearings (and work to have them fitted), plus I want to hone the other 3 cylinders and replace the rings on those pistons. I would replace the pistons too, but thats just too expensive. Since I bought the Bonnie, I've had serious cash flow problems (but its worth it), so projects like this are, unfortunately, on the backburner indefinetely.
20/8/03 - 23/8/03
Update at last!!
Ok, the crank has been rebuilt for quite a while now, and the three other
cylinders have been honed. I also decided to replace two of the other pistons
as they looked a bit dodgey. The mainbearings for the crank cost $170, the
trick here is that the inner bearings (either side of the labrynth seal) are
the same as the end one (the one without the groove for the half clip). This
will save you huge $$ over the cost of the "crank sub assembly" which is what
Yamaha want to sell you at a cost of over $800! The new Wiseco piston kits
were $155 each and a set of rings for the one piston I wasnt replacing was $45.
Things didnt get off to a good start, when we went to assemble the crankcase halves we found a crank seal missing. Since I didnt have my parts book with me, I assumed I had ordered the seal but either lost or not received it. I reordered using a part number from the invoice feeling that since that was the only seal I couldnt find that must be it. It turned up the next day, but it was the wrong seal. It was the part number I ordered, but I had ordered the wrong part! A quick check of the bike shops microfische revealed the correct part, amazingly they had the seal in stock all along!!
More fiddly stuff like cleaning the gasket gunk off the tops of the cylinders and giving them a further light hone (there was still some scoring) meant the final assembly didnt start until Saturday. While cleaning gunk off the cylinder head nuts with a wire wheel on a grinder, a nut was grabbed by the wire wheel and flung to parts unknown. It happens, but the problem was this was 12:30pm on a Saturday in a country town. Chances of getting a replacement? Not good. However, luck was with us again, and I found a shop open and got a nut no trouble.
Putting the transmission oil pump drive gear on presented new challenges. The circlip was gone! Considering the motor has been in peices for 6 months, only losing one circlip is a bit of a miracle really, but still a huge problem as I wanted to get the motor together for refitting to the bike on Sunday. Another mercy dash downtown, and I managed to get some circlips, but they were imperial. Hmmmmm, bit of squishing with pliers and one (now oval shaped) circlip clicks into place on the shaft.
On the home straight now, but still I manage to snatch defeat from the jaws of victory. Fitting the engine cover (clutch side) the manual refers to a "union bolt" that goes in behind the water pump. Nothing resembling a union bolt (I'm thinking union as in banjo union type bolt). No parts manual to check it against. "F#&k it!" I've got a headache, time to admit defeat and relax for the rest of the weekend (and the last of my holiday).
There is of course no union bolt, its just an ordinary bolt which I had all along... The motor is going back together this week (25/8/03) and will possibly be back in the frame and running this weekend. Stay tuned...
2/9/03
Ok, I had a cold and didn't put the motor in on the weekend. Plus I would have only had one day to do it in and Murphy's law being what it is, I refuse to attempt this in anything less than two days. This weekend it will be!
6/9/03
Motor fitted, everything bolted back up except the upper left hand cylinder exhaust which we were supposed to be fixing the rust hole in but forgot. Doh! Mercy dash to get it.
7/9/03
Fixed the hole in the exhaust with a smear of silastic, peice of Coke can and a wad of steel wool jammed between the heat sheild and the pipe to hold it against the exhaust pressure. What? Got a problem with bodgey repairs, it'll probably last for years! Bled oil pump, filled cooling system. Cooling system leaks. Damn! Luckily the water pump cover was just a bit loose. Replace and reroute the fuel line to the right hand carbs so that it's actually possible to hook up the fuel system. Gearbox oil in, tidy up fiddly little bits of wiring etc etc.
Right, its time to put the tank on. Not too much fuel spilt, I didnt have a container to dump it in. Really must but a dry break fuel connector or two one of these days. Ok, the moment of truth...kick...kick...kick..kick It started here last time...kick...kick...kick burble burble burble. Its ALIVE again!!! Woohoo. Hang on, hmmmm, that sounds more like a V3 burble than a V4 burble. Upper right hand cylinder spark plug is dry as a bone. Crack the drain on the float bowl and let some fuel flow through. Beautiful! Back to a throaty V4. I should mention that I had no bodywork on the bike apart from the tank at this stage, you'll only have to take it off to get the bike to start after a rebuild!
Now all I need is a new rear disk and a new set of fairings + decals, top quality paintjob and it'll be good as new! Given that it only took 11 months for me to be able to afford the unexpected crank rebuild, it should be in concourse condition in about 10 years ;-) I'll have a movie of it running soon, as well as photos of the rebuild.
11/02/04 - 16/02/04
Geez, I havent updated this page for a while. I bought some dry break fuel connectors (thats not what they call them, but thats what they do) from Australian/Italian Importers (03) 9602 4400. They were bloody expensive at $70 each (one for the "On" line and one for "Res"), but well worth it in my opinion as it saves so much hassle with fuel going everywhere whenever you take the tank off.
What else... I pinched the oil delivery lines when I was putting that little plastic cover they go under back on :-( I was running a bit of premix but not much, I dont think any damage was done, but I dont know for sure :-( Aside from that, the bike ran like a pig anyway, constantly dropping cylinders which loaded up the other cylinders until they fouled the plug and conked out too.
I gave up for a few months as I was too busy and had no spare money, but eventually checked out the spark as it was the bottom two cylinders which stopped running first. The spark was very weak which led me to check the coil. It was ok on the primary winding, but the secondary winding, where the high tension leads come out was open circut. This doesnt seem to make any sense as there should have been no spark at all, but I checked with three different multimeters. Also the screw part of the spark plug cap on one cylinder had broken off, no wonder I was having spark problems!
SuperMoto New Englad (the best bike shop on the planet) tracked me down the last RZ500 coil in stock in Australia which I fitted. Fully expecting it to rumble into life I kicked...And kicked and kicked and kicked and kicked. You get the picture. Basically if my RZ doesnt fire up by the third kick, you've got problems. I checked the spark, still weak and I had to turn the motor over quite fast to get any spark at all. Hmmmmm. Time to charge the battery overnight.
Attempt #2, fully charged battery. Now the spark is there more readily, i.e you dont have to turn the motor over so fast, but its still weak. Oh well, kick etc etc. Pull the plugs, they're dry but I can hear fuel in the tank. Tap the carby bowls and try again. Getting well pissed off by now. Pour about 2.5 litres of fuel in the tank, success!! It fires up and immediately settles into a smooth idle. There's nothing else in the whole world like the sound of a V4 two stroke. Its billowing clouds of blue-white smoke, but thats not unusual. I let it run for about 15 minutes to get good and hot, then I restart it a couple of times just to hear that sweet sound (and to make sure it will restart).
I'm all set for a blast to the end of the driveway and back when I feed out the clutch. Nothing. Doh! As I take the sprocket cover off I remember that it felt like it was pressing on the pushrod as I bolted it on. I try the bike on the paddock stand with out the sprocket cover on using the rear brake to load the drivetrain, its perfect. Hmmm how did the clutch get so far out of adjustment? I might have to check if I put it back together correctly, but for now I will adjust it, but its too late at night now (10:45pm) to play much more.
Before going to work I fired up the RZ, just to make sure it would. It did, easily :-) Only problem is that the upper left carb is flooding fuel out the overflow. Dicky needle and seat, luckily I have two spare carbs so I take the needle and seat out of one and the problem is solved. Used the opportunity to fit two inline fuel filters (one for "On", one for "Res"), but now it wont start. The plugs are dry, I think I will have to replace the diaphram inside the fuel tap. Eventually I get fuel into it and it starts, but only running on three cylinders. It runs breifly and conks out. :-(
What I think is happening is that a) these plugs are dicey as they've been fouled before and I just cooked them up red hot with my propane torch to get them going again, and b) because the fuel is sometimes taking so long to get to the cylinders, by the time it reaches all of them, the ones that have had fuel longer are either flooded or fouled. I cook the plugs again and (after they are cool again) it fires up first kick, but drops cylinders as I try to test the clutch up the driveway and dies alltogether.
Much cooking of plugs and kicking and sweating profusely later I give up on the plugs and decide to get new ones. Its Sunday by now and I must wait until SuperMoto New England (the best bike shop on the planet) opens up again. Somewhere in there I decide it will be a good idea to check the oil pump adjustment. Yikes! Its not even close, the amount of oil it was delivering, its a wonder I didnt use more oil than fuel! But, of course, now the cable adjuster is full of rust which no amount of WD-40 will shift. I cant get it off the cable to re-tap the thread beause of the cable end, so I file two grooves in the male part of the adjuster so I can use it as a tap. About one hour and 12mm of movement later its done. The pump is still set slightly on the rich side, but only just.
Comparing the oil pump this morning (16/02/04) with how it was before I adjusted it, I would say that previously at idle it was delivering as much oil as it will now do at full throttle. No wonder I was having trouble with fouling plugs! Will pick up new plugs this afternoon from SuperMoto New England (the best bike shop on the planet) and try again once the temperature drops a bit, its another scorcher today.
Just for laughs I decided to price a few bits from Yamaha to get my bike back to as close as possible to the condition it was in when it rolled out of the showroom (its got a long way to go!)
| Part number | Status | Description | Price AU$ |
| 1321811301 | # | Cover, shift pedal | $4.94 |
| 47X2810000 | * | Tool kit | $114.43 |
| 47X2814A00 | NLA | Wire hook | $44.61 |
| 1A82151800 | # | Holder cable | $5.50 |
| 41Y2314500 | # | Oil seal | $18.98 |
| 47X2470500 | * | Seat lock | $72.64 |
| 31A2583101 | NLA | Disc brake R.H | $323.29 |
| 31A2583111 | * | Disc brake left | $323.29 |
| 47X2583150 | # | Disc brake | $408.47 |
| 47X2834300 | * | Guard stone | $108.26 |
| 51X8211700 | * | Wire lead | $32.79 |
| 47X1317400 | NLA | Holder oil | $11.65 |
| 47X1443700 | NLA | Duct | $30.21 |
| 9170206075 | NLA | Pin clevis | $4.74 |
# means in stock Yamaha Australia, * means available via Yamaha Japan, and NLA means No Longer Available. We start to see this one more and more with RZ500 parts :-(
Most of the parts are explained by their description, but for those that arent: wire hook is the original wire that is used to hold the tank up. Holder cable is the holder that goes in the front mudguard to take the speedo cable and brake line(?) Oil seal is the fork seals. Disc brake R.H and left are the two front discs (only one is available?!) Disc brake is the rear disc. Guard stone is the grille which attaches to the front of the belly pan. Wire lead is the wires used to connect the battery to the wiring loom, I know I was being lazy, but I thought it would only be a couple of bucks! Holder oil is the rectangular grommet which the oil lines pass through as they go under that little plastic cover, there should be two, I only have one. Duct is a rubber thing which goes on top of the airbox. Pin clevis is the bottom anchor for the fuel tank.
I'll definetly get the gear lever rubber, and I'd like the tool kit just for authenticity, but we'll have to wait and see. Seat lock is also a problem, I've searched the wreckers for all these bits to no avail. Got an offer of some discs but I think they are below the service limit for thickness. Before I lose it, here is a part number for the rubber plugs which go in the bottom of the cylinders. There is no listing in the RZ parts book, this partnumber is YZ125 but it fits perfectly (thank goodness Yamaha is a parts-bin manufacturer). 47X113550000 Seal cylinder. They're about $4 each, I replaced mine since I had all the cylinders off and the original plugs were a bit hard. Better safe than sorry.
17/2/04
Picked up the new sparkplugs yesterday afternoon, no joy :-( It ran breifly after kicking it with full throttle (it was flooded again), but only on the lower lefthand cylinder. I held it for a while hoping the other cylinders would kick in, but had to give up as this is an excellent way to seize a piston.
Time to get serious, I've spent shitloads of time and money on this bike and it was running better two years ago! I sprayed all the connections to the CDI and YPVS controller, then lifted the tank and pulled apart all those connections and sprayed them too. Over to the lefthand side of the bike and I pulled the stator connectors and cleaned them too. Tried to check the resistance as per the troubleshooting section of the manual, but my multimeter is dodgey so will try to get a new one today.
While doing that I noticed that on of the connections appeared to be filled with what can best be described as dirt. I cleaned it out with a drill (by hand) and WD-40. I dont know if its just because it was dark when I checked the spark, but it seemed to be stronger, certainly it was a bright blue colour whereas before it was purple. Still thin though, I would prefer it if the spark was a nice big fat one the diameter of the centre electrode.
Either way, it finally fired up after only a couple of kicks and started purring away on all cylinders. I should mention that while I was fiddling with the electrics I decided to tackle the clutch which still isnt working (I tried to bump start the bike). Turns out I had the clutch pushrod in backwards. Dumb mistake, but there you go. It has a reduced diameter one end which fits into the clutch actuator, if you have it backwards it cant go in and so the clutch is always slightly disengaged.
While I was in that area I decided to attack the neutral indicator switch as the neutral light was no longer working (this pissed me off too as it used to work). If you touched the end of the wire to any earth point the neutral light came on, so I knew the wiring was ok, therefore the neutral switch wasnt making contact somewhere. Had I put the shift drum in wrong? The manual has a troubleshooting chart for the neutral indicator light, at the end of the first chart it says to refer to troubleshooting chart 2 to check the neutral switch. Well, I've been through that manual quite a few times, and I couldnt find the neutral switch troubleshooting chart.
I decided to pull the switch out which was scary becuase I wasnt even sure that you could remove it (although it has flats on it like a bolt) and I really didnt want to damage it as I wasnt sure I could get a replacement. Anyway, it came out no problems, gearbox oil went everywhere (as I suspected it would). The switch is really simple and was ok as far as I could tell (dicky multimeter remember), so I screwed it back in. Because its plastic, I was being careful and did it up to what I thought was a reasonable torque. But when I tightened the screw that holds the neutral indicator light wire on I noticed the switch was turning! So I removed the wire and used the screw to tighten the switch up instead of the socket I had used before. Reattach the wire and success!
I assume what happened is that when I removed the screw to take the neutral indicator light wire off while removing the engine from the frame, it unscrewed the neutral switch ever so slightly so it no longer made contact. Now, where was I?
So it was purring away, neutral light works, time to test the clutch then. I backed out of the garage, click first gear and feed out the clutch. We're away, but not much power. I turned around at the end of the driveway and head back, it seems to be dropping cylinders under load. One more squirt to the end of the drive and its getting worse. I just get back to the garage (we're only talking about 10-15 metres here!) and it conks out.
Too late to run it anymore tonight even if I could, so I syncronize the upper and lower carburettors. The righthand pair are out a bit, but the left are ok, although syncronizaton between the lefthand and righthand sides seems to be out. Cant be arsed doing anything about it now though. It was still blowing clouds of smoke, I think I will try and squeeze a bit more adjustment out of the oil pump. I read the other day that they overoil a bit when set to the factory setting and it was suggested to set it 1/6 - 1/8 of an inch on the lean side. No way I can get that much adjustment, but I'll try and get it to factory specs.
Might ditch the two stroke oil too, I'm using Castrol TTS2 fully synthetic but I've had trouble fouling plugs in the IT250 with that oil when things werent right (i.e too rich from a dirty aircleaner). Which reminds me, pull out the aircleaner element, yuck! Its fairly dirty (I can see things on the surface) and super, super oily. Will clean it today (17/2/04) and perhaps try the trusty Mobil Extra 2T semi synthetic.
9/4/04
Ok, I havent forgotten the RZ, I've just been really busy. I got rid of my car and got another secondhand one which needed some work plus I've been gettting my house ready for renting out so I havent had time to work on the RZ for a while. Also I hit my thumb really hard with a hammer which wasnt conductive to doing more work!
Its waiting patiently for me in the garage, and I will get back to it soon (I hope)
27/9/04
The madness is upon me once again! It's time to attack the RZ. I've actually been motivated for a while, but lacked the time due to fixing up my dodgey car and fixing my really dodgey dirtbike.
Anyway, where were we? Well, I pulled out the air filter about 7 months ago and it promptly disintegrated. Great. So I got a new genuine one and finally got around to installing it last night. I had to clean out the airbox first, as whatever oil was in the old filter had turned to goo and there were bits of partially disolved air filter stuck all over the place. Then I cut a gasket to go between the top and bottom halves of the air box. I'm not certain this is actually needed, but there was some kind of foam rubber which was now well past its use by date in there (I had to chuck it out) so I thought I'd better put something back. I cut it out of an old inner tube cut and laid out flat, it's less than ideal so I'll check the parts listing and see if there needs to be anything in there at all.
I put about 1 litre of Mobil Extra 2T in the oil tank (I drained the Castrol ages ago), and bled the oil pump. Next, time to clean the plugs for about the eight hundredth time. I checked the spark, yep, that pathetic feeble RZ500 spark was there. Why is that? Why does the RZ500 have such a pathetic spark? Maybe I'll try some car ignition coils. So then it was time to dance! It went the usual way, I kicked and kicked and kicked and kicked and kicked until I was out of breath, then I kicked some more. As usual, the RZ remained slient. Time to pull the plugs, lower plugs wet, but not too wet, upper plugs dry as a bone. How is that possible?!!! The fuel has to run through a T junction right at the upper carbs before it can get to the lower ones! ARRRGH!
I cracked the drain screws on each carb and watched fuel come out (the fuel tap was already switched to prime), so there was fuel getting to all the carbs, why not the cylinders? Sigh. I put the plugs back in and try again, run out of breath and give up. The battery is quite weak having sat for 7 months, perhaps thats part of the problem? I try the horn and the neutral light goes out. Hmmm, there's not enough charge to run the neutral light and the horn at once (horn didn't make any noise either). I pull the battery and whack it on the charger, maybe a fully charged battery will help? Ha ha ha ha ha ha! Yeah right...
28/9/04
Tried with a fully charged battery, not surprisingly there was no difference. Consultation with the workshop manual ignition system trouble shooting section reveals tests for the stator coil and ignition coils which I recall doing before. I do them again anyway, and they check out fine, the next step in the troubleshooting is to replace the CDI unit. Thanks for nothing Yamaha! Guess it's time to follow that line of inquiry as this is really giving me the shits badly. As a final test, I put one of the plugs into the IT250 plug cap and kick it over to compare the spark. The IT has a nice bright blue spark, even turning the motor over slowly. By contrast the RZ500 has a weak purple spark and only if you turn the motor over fast. Looks like this problem is beyond my ability to repair.
29/9/04
On the recomendation of SuperMoto (the best bike shop in the world!) I contact Betta Bikes in South Australia. The guy I talk to is friendly and helpful, for $55 they will load test the whole ignition system then quote on necessary repairs. Load testing is vital as resistance testing can only reveal so much about the heath of your ignition system. This should be $55 well spent (a new CDI is $919, yes, that's right folks, nine hundred and nineteen dollars), will pull the stator and both ignition coils off tonight and send them off tomorrow.
29/10/04
Got the bits back from Betta Bikes but heading down the coast for the weekend so will have to put it back together next week.
2/11/04
Put it back together and checked the spark, still looks the same as before, possibly I don't have to spin the motor as fast as before, but it's hard to tell. Betta Bikes bench tested the stator, ignition coils and CDI and found no fault besides a small leak to earth at high rpm which wouldn't affect starting. I had the stator repaired anyway because presumably I will get this running one day! Anyway, in with the plugs and lets give it a try. Added a bit more fuel just to be sure, and wouldn't you know it, the bloody cantankerous beast decided to fire up. All was not well though (surprise surprise). Instead of the smooth V4 rumble I got a weird surging rough idle kind of brrum----brrum----brrumm, like it was firing on alternate cylinders or something instead of brrumbrrumbrrumbrrumbrrum (forgive the childish description, but it's hard to explain unless you heard it). One possibly important thing I noticed is that the tacho wasn't working, but intermittently the engine would drop into smooth, normal running and the tacho started working.
There wasn't much more I could do, as once again I was completley mystified by the RZs refusal to behave, and it wouldn't run if you opened the throttle. Since you can only run on choke for so long I gave up. I did come back later in the evening and fire it up again, just to see if it would basically. It did, and this time it was idling smoothly, but as soon as you cracked the throttle even the smallest amount, the tacho dropped to zero and the engine died. Truly bizzare. I will ring Betta Bikes and see if they can offer any advice.
3/11/04
Well Steve from Betta Bikes isn't there at the moment, so I'm on my own until next week. Well not entirely on my own, I did post a question at http://www.yamaha-rd.com/ but no one could really shed much light on the situation. One thing I did discover is that the strange running might have been attributed to the fact that it was only running on the left hand cylinders (well it was tonight anyway). I pulled the plugs and they were all wet, so fuel isn't a problem. However it would seem spark is - mine is now gone all together. Where did it go? Stuffed if I know, but I suppose on the upside at least now I've got a hard (as opposed to intermittent I mean) fault it should be easier to find...I hope...
I pulled the upper fairing off and began investigating the wiring from there. Didn't take long to find some scaryness, two black wires piggy back soldered onto another, one yellow wire piggy back soldered onto another. Hmmm, not great. I suspect that a large section of the bike has been rewired for some reason, but at this stage I will just redo the insulation tape and see if I find anything *really* bad further along.
11/4/05
Surprise surprise but I gave up on the stinking RZ500 again. Spark, no spark, running on 3 cylinders, running on 2 cylinders. It all got too much!! So whaddya gonna do? Buy another one of course! Crazy isn't it, but there you go. Have a look. At the moment I'm canabalizing this bike to tidy up the new bike which is running and registered since this one's been so naughty and wont work, but I haven't taken much off it and will make sure it gets back to the correct condition in time.
I think I might know where the spark went though, since I briefly had the same problem on the new bike (you can bet I was shitting blue lights when that happened!) Same symptoms on the new bike, i.e. no spark whatsoever. Zero, zip nothing, nada. I had bumped one of the wires on the pickup on the stator which triggers the cdi to fire the coils while removing the left hand carbys. So hopefully armed with this new knowledge I can find the problem on this bike. That, and I will try changing the stator over as I was talking to a mechanic about the problem and he said he had once had a stator rewound and although it measured correctly it didn't work and had to be rewound again!
25/7/05
Well, just over three months, that's not bad considering how long it usually takes me to get back to this bike. I treated RZ#2 to new headstem bearings, which snowballed into new paint for the wheels, new wheel bearings, new chain and sprockets and new tyres. I also replaced the sight glass as I couldn't see if it was eating all it's gearbox oil (I suspect it was, but it doesn't seem to be since I whacked some thick diff oil in there. Yeah, yeah, whatever, I'll be buggered if I'll split the cases on this one, look what happened last time I took an RZ500 motor apart!!)
Anyway, where was I? Ok, RZ#2 is running good, handling a million times better than when I got her and just generally being what a motorcycle should be. So after a major reorganise in the garage I find myself actually having access to RZ#1 again. So lets check the pickup coil resistance, it's perfect. Check the wires to the CDI, again, AOK. Hmmm, well, as silly as it seems, what with my stator all being tested and reparied and such, I'll just give it a test anyway since I'm in the area. Looking for 118 ohms, I find I have an open circut :-/ Not real impressed considering the dough I forked over. Since it's been so long since they did the work I doubt they'll fix it under warranty (assuming they offer any warranty on their work) so I'm not 100% sure what to do. I don't really want to send it all the way to South Australia again anyway so I'll check my options. See you in another 3 months.