1990 Yamaha Exciter Restore

grasshopper

grasshopper

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I found a PDF for a 91-93 exciter II manual. I own an 1990 Exciter. Is the manual the same? What difference if any?

I'm in the process of a complete rebuild right now. Sled is in good shape, starts up runs but has low compression 90psi. I'm going to do perform the following and will post pictures along the way.

- Top and bottom end refresh / rebuild. Depending on what the pistons and cylinders look like I may just do rings and circlips for the top end. If the crank feels ok I may just do crank seals.
- New Fuel and oil lines
- New wheel bears
- Shock refresh
- Rear Ride height raise
- Jack shaft bearing replacement
 

There are some differences but most of the tech info in the manual will transfer to your 90. The biggest difference is the rear skid and ignition. Totally different. You might want to wear a diaper when you get the price for the jackshaft bearing. Yami is stupid expensive and you will be better off going to a bearing house for it.
Use OEM crank seals. Im going to guess your mag side cylinder is low on compression??
 
Throttle Junkie35 said:
There are some differences but most of the tech info in the manual will transfer to your 90. The biggest difference is the rear skid and ignition. Totally different. You might want to wear a diaper when you get the price for the jackshaft bearing. Yami is stupid expensive and you will be better off going to a bearing house for it.
Use OEM crank seals. Im going to guess your mag side cylinder is low on compression??
Click to expand...

All balls has the bearings for the jack shaft. They were 27 bucks. Hopefully they are the correct ones.


http://m.ebay.com/itm/331258592135?_mwBanner=1

Both cylinders had exactly 90psi.

I'm going to do a leak down test now that I have the carbs and exhaust off
 
Those leads are pretty fragile at the point of attachment. You can by-pass those switches by unplugging them from the main harness, then plug the two leads from the harness into each other. A tether switch is a good idea if you decide to delete the switches permenently.
 
Ok I'm in full blown snowmobile restore mode now. I got the motor out and the top end off last night. The sled seemed to run fine when I bought it for 500 bucks. So I figured anything that runs is worth 500 bucks. I'm glad I took the time to tear it apart because it would have for sure left me stranded. This is a good piece of mind tear down and refurbish job. I also found the primary clutch had a crack in it. I ordered one of those off ebay.







 
Are the cylinders on this snowmobile nikasil or can they be bored?

What is the easiest plan of attack to replace the crank seals getting the bottom end apart? I only want to tear it apart as far as I need to to get to the crank seals.

My plan:

- Either clean up the cylinders or send them out for refurbish. Not sure on that yet
- Need a suggestion on piston kit - Wiseco standard bore is 200 bucks. SPI has just the pistons, rings, wrist pins and circlips for 75 a piece.
- The winderosa gasket set has all gaskets including crank seals. I'm think go with this. I'm hoping it has the top end gaskets if I plan to go with the SPI pistons
- I have the jackshaft bearing kit from all balls and going to replace that.
- I have new fuel and oil lines
- Some wheel bearings on the rear skid are shot. Going to replace the ones that are wobbly or don't roll right
- The rear brake is shot so service that during jackshaft bearing replacement

Thoughts, comments, criticism?

Paid 500 for it and by the time I'm done I will have close to an extra grand. 1500 dollar sled isn't too bad in my book knowing everything is right.
 
If your cylinders are in fact 1990 cylinders they are sleeved and can be bored. Do they have score marks that you can feel with your finger nail?? If not, I would give them a light hone then measure them to see if in fact they need to be bored.
I have been running SPI pistons and have no issues. You will get mixed opinoins about Wiseco's. Oem is always the best, but sometimes the price exceededs the value.
I have found widerosa to be the better of the aftermarket gaskets on the Exciters. The base gaskets are cut better than Cometic. Be sure to use some Yamabond 4 or the like on the base gasket with the aftermarket kits or they will most likely leak eventually. You will have to Torque the head/cylinder nuts/bolts after several heat cycles and then repeat a couple of times after. The after market kits compress more than the OEM and take a while to fully seat. Here again OEM is better but the aftermarket kits can be dealt with. If you do not have rubber plugs in the bottom of the cylinder, order the 91-93 Exciter gasket kit because of the way the base gaskets are cut.
As far as crank seals go, I have been using OEM when ever possible. Widerosa's are ok, but not my first choice. I dont think they are as durable as the yami stuff.
You will need to tear the rest of the engine completely apart to replace the crank seals. There is no way around that. Also I would have your crank checked out to see if it is true. Running a sled with a damaged clutch like that can throw the crank out of whack not to mention what ever caued the crack. Good luck on your rebuild.
 
Throttle Junkie35 said:
If your cylinders are in fact 1990 cylinders they are sleeved and can be bored. Do they have score marks that you can feel with your finger nail?? If not, I would give them a light hone then measure them to see if in fact they need to be bored.
I have been running SPI pistons and have no issues. You will get mixed opinoins about Wiseco's. Oem is always the best, but sometimes the price exceededs the value.
I have found widerosa to be the better of the aftermarket gaskets on the Exciters. The base gaskets are cut better than Cometic. Be sure to use some Yamabond 4 or the like on the base gasket with the aftermarket kits or they will most likely leak eventually. You will have to Torque the head/cylinder nuts/bolts after several heat cycles and then repeat a couple of times after. The after market kits compress more than the OEM and take a while to fully seat. Here again OEM is better but the aftermarket kits can be dealt with. If you do not have rubber plugs in the bottom of the cylinder, order the 91-93 Exciter gasket kit because of the way the base gaskets are cut.
As far as crank seals go, I have been using OEM when ever possible. Widerosa's are ok, but not my first choice. I dont think they are as durable as the yami stuff.
You will need to tear the rest of the engine completely apart to replace the crank seals. There is no way around that. Also I would have your crank checked out to see if it is true. Running a sled with a damaged clutch like that can throw the crank out of whack not to mention what ever caued the crack. Good luck on your rebuild.
Click to expand...

Thank you for the advice and insight.
 
We are in full blown snowmobile refurbish mode ladies and gentlemen. I've built plenty of motorcycles in my life but I'm losing my virginity and popping my cherry all together on snowmobiles now. This thing isn't that complicated compared to Grand Prix bikes. LOL!

Tonight I plan on cleaning the cylinders and performing a hone to see if they clean up good enough to use. I measured the skirt of the pistons this morning and the cylinder with a caliper and they both measure just shy of 73mm. So that's good news that they are stock bore.

I'm having an issue getting the cog axle nut off. I've heated it up and I still can't break it loose with the impact. The bearing on the left hand side behind the speedo drive popped out after heating it up trying to free the nut. I think the inner part of the bearing is seized to the shaft. I will try heating it up again to free it up. It's a good thing I caught a hair up my *** to do this because this thing needed some major TLC. When I'm done there won't be a thing I don't know about it.



I have several bad wheel bearings on the rear skid and the rear shock is locked up. Suggestions on service or replacement on those components is appreciated



And I have the jackshaft bearings as well to replace so I plan on doing that.

 
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Tell me about some upgrades I can do to this with parts that swap from different models of yamahas?

- Clutch?
- Suspension?
- Tracks?

ect....
 
YooperWoods said:
You might want to put the brake back on so you can lock the jackshaft and keep the drive shaft from turning. Then use a breaker bar to get that nut loose.
Click to expand...
Yooper woods is correct. The brake helps. Or you can put a 1'' wrench on the drive axle as well. It might be 1-1/16''?? I cant remember exactly anymore. Its been a while since I had a drive axle nut give me a headache.
Your cylinders look like you have only some transfer from the piston. They should clean up nicely with muriatic acid and a light hone.
Your going to find a lot of seized and possibly cracked/broken parts in your skid. I have everything you need to freshen it up. You have my number.
 
The brake is shot to. :)

Honed the cylinders tonight and they turned out good. Onward
 
This project is coming along. I got pretty much all the parts I need in yesterday to rebuild the motor. I found that behind the flywheel side of the bottom end there was some ooze coming out so that pretty much proves that crank seal was a bit leaky.

 
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