1983 YTM200 trouble splitting the case and removing the timing gear from the crank.

[Tanman496]

Hi all I am doing a total overhaul of a 1983 ytm200k and Yamaha uses Phillips screws to hold the case together and about half of them are oxidized and I have been using a impact driver to try to get them out but not having good luck and my second issue is removing the gear on the crank that turns the timing chain. Looking for any help or special technique that you guys might use.

[MonroeMike]

Those are JIS screws. not Phillips, just so you know.

http://gofastinnovations.com/

[Tanman496]

Thanks Mike I will get a Jis screw driver but I am not messing the head of the screw up it won't turn at all. It's like oxidized.

[El Camexican]

Thanks Mike I will get a Jis screw driver but I am not messing the head of the screw up it won't turn at all. It's like oxidized.

You have to beat those screws so hard at times you might think you're going to break the cases. Just make sure you don't miss the impact driver and ventilate your engine with the hammer. You can heat them with a torch *carefully* first, it might help loosen the corroded threads.

[MonroeMike]

I use penetrating oil (Kroil or GM heat valve lubricant are my favorites) on those corroded screws. I set the engine on it's side (or the whole bike, if it's still in, oil and gas drained first) to let the penetrating oil get down in there. I also tap the screw heads with a small brass drift to help loosen the corrosion. I have had some take days to loosen (or not) spraying/tapping multiple times each day (bikes that sat outside for years).

That being said, I have used Nico's methods also, when mine failed and I'm pissed.

[Tanman496]

thanks again MIke , what about the timing gear on the crank it should come off with a gear puller am I right?

[Tanman496]

Thanks El Camexican for your input and I already broke the clutch side cover at one of the screw corner before posting my thead.

[DAM shop]

Send a pic of the timing chain gear you are attempting to remove

[Tanman496]

247568 Dam shop I hope this works I tried to post a picture of the gear for you.

[Tanman496]

Thanks for your help guys I got the case apart so I am all set . Thanks again

[DAM shop]

247582
Here is the info on your sprocket..

[El Camexican]

Thanks El Camexican for your input and I already broke the clutch side cover at one of the screw corner before posting my thead.

Oh, man, that sucks! What's your repair plan?

BTW, when I get to the point that I think I might break something and the screw looks more like a rivet that a screw I sometimes spot weld an old screw driver to what's left of the head. The heat almost always breaks them loose and then I just spin them out with the screwdriver.

[Tanman496]

247582
Here is the info on your sprocket..

thanks for the info I need to get a repair manual.

[Tanman496]

El Camexican I owned this tri moto back in 2001 and it past hands many times since so my girl friends son ended up with it and when I told him I owned it back in the day he gave it to me so I figured it was up to me to do a full restro on it. Its a 1983 Ytm200 the frame wheels and have fresh paint and I installed new rearend bearings and new steering stem bearing. Now I am rebuilding the engine. What I am trying to find is a good rear fender for it.

[DAM shop]

Tanman,
Check ebay for your fenders, I saw a few what appeared to be good sets of rear fenders for an affordable price..