New Project - Not a GS but still a Suzuki

[Guest]

I brought this bike home last night, a 1994 Suzuki RF900R. I've got two standard bike and wanted a sport touring machine. Didn't pay much for it and it had a clean title. Bike has not run in about 3 years. The PO told me that the bike lost 2nd gear and now the bike is stuck in first gear. There is something definitely wrong with the transmission. First order of business is to remove the engine, take it apart and see whats going on with the transmission. It is missing some small parts but mostly everything is there. The plastics have a few cracks but all in all it seems like a solid bike. If any one here has one of these bikes I would like to get your feedback on it.

Here are some pics of the bike:

[akckhim]

The rf900s are a very nice bike had great reviews when they came out good score.

[almarconi]

I removed the engine and completely took it apart. Spent about 8 hours so far.

When I removed the oil pan, I found this:


Upon further inspection I found this:







That is what is left of third gear. I was lucky to find a used transmission on ebay so it should be a relatively easy repair, just very time consuming. It makes sense why the PO lost a gear and the transmission was stuck. There was bits of gear stuck every where.

Now I have to clean everything so I can start measuring. I am really enjoying this project so far

[almarconi]

Have not been working much on the project lately. After a more thorough disassembly and inspection of the output shaft, I noticed wear on 2nd gear. It really is hard to see the wear until everything is taken apart. I opted to replace 2nd ,3rd and 5th gears just to be on the safe side. The counter shaft gears showed very little wear. After measuring the shift forks, I decided to replace all three forks and the shafts also. The shift drum had some deep knicks on it so that will be replaced as well. Pretty much ready to start reassembly.

[Nessism]

Looks like a fun project. Thanks for the nice photos.

I had a RF600 for a short time and enjoyed it. Suspension was sort of choppy but bike handled nicely.

[chef1366]

Chew it up and spit it out
Subscribed.

[wedoo2]

What caused that? Poor metal (I doubt that), poor shifting, bad clutch, downshifting? No oil (if that was the case there would be engine problems I imagine)?

[dazzo]

Been wheelied alot from the sticker on the seat unit i guess?

[Bevo]

Im having trouble seeing the damage on those gears

If your that deep in and the engine is out it may make sense to pull the top end and inspect with a new set of rings and a valve job...can't hurt at this point.
Don't forget the crank!

I would hate to do all that work only to find I have to take it all apart and do something else and hey, your having fun so keep at it!!

[quexpress]

Subscribed!

I need to do this to a bike that can't go from second gear to third (can only use 1st or 2nd) ... but I will then be out of my comfort zone (am not very familiar with xmissions).

Thanks for the great pics and info!

[steve murdoch]

Notorious for the 2nd gear problems, a buddy had one years ago.
Under cutting transmission dogs was a recommended fix but the cost of a Fast By Gast fix was very high. He ended up using an early 90's GSXR 1100 transmission.
I like the look of those bikes.

[almarconi]

Under cutting transmission dogs was a recommended fix but the cost of a Fast By Gast fix was very high. He ended up using an early 90's GSXR 1100 transmission.

I've gone back and forth about having the transmission undercut, at least 2nd gear. I am not an aggressive driver and I can count on one hand the times I've missed a shift. In the case of this bike, I'm sure it was abused. The PO was a young guy with a driveway full of wrecked cars and bikes. He had a gsxr 750 that he blew the head gasket on trying to keep up with the big boys. You get the picture. It would seem that the transmission can jump out of gear at wide open throttle. The bike has a top speed of about 160 mph, I don't ever expect to have the bike at WOT in any gear much less 2nd. Having 2nd gear undercut is about $150 but I just can't see spending the money for my situation. I have replaced all the suspect transmission parts with new OEM parts, don't plan on driving like a crazy person, so I don't think I'm going to have any issues with it.

I've already cleaned up the head and replace the valve seals. I also plan on a hone and fresh piston rings. There was very little wear on the bores, mostly some rust spots where the pistons were sitting. The rings were stuck on two of the pistons again from sitting.

[almarconi]

Well its been along time since my last post. I am happy to report that the engine fired up and runs great . Still need to sync the carburetors and fine tune everything.

The transmission now shifts the way it should. I ran into a bit of a problem when I installed the transmission. The replacement counter shaft I used was from a 95 and did not fit the 94 clutch hub. I ended up having to use my original shaft and swap the gears. It sucks having to tear down the bottom half of the engine when you realize that the clutch basket won't bolt on. A definite WTF moment. I ended up installing a factory pro shift kit and a four degree advanced ignition rotor. After I installed the engine, I rebuild the rear brake caliper and rear master cylinder. While I had the wheel removed, I installed a new 530 X ring chain and sprockets. I kept the stock rear sprocket and went down one tooth on the front sprocket. Supposed to give better acceleration off the line.

I am going to replace the tires at some point but I wanted to get the bike running first. I noticed that both the wheels have flat spots in them. The tires hold air so I don't know if this will be an issue or not. Now that the mechanical work is pretty much done I am going to start working on the body work. The tank has several dents and some rust that needs to be taken care of. The plastics have numerous cracks and holes that will need to be repaired. My plan is to get the bike tagged by the spring time. All and all this has been my most satisfying old bike restoration to date.