strange rh crank o ring set up?
 

Hi all.

Me and a buddy are into a complete rebuild of a 01 ec 200. The crank main drive gear is put on with a cir-clip, and there is a bushing which the seal rides on to create seal. on all gasgas i am familiar with (have 2 an 02 xc 250 and txt 280) and according to the only manual circulating currently, the oring goes against the crank, then bushing, then tighten nut against drive sprocket. which creates seal. This one however looks like there is a groove in the crank, which you slide a thin o ring into then slide bushing over so o ring is actually inside of bushing. Has anyone seen or is familiar with this setup? is it 200 based or year based? or am i out of my mind. in ordering parts we got an o ring which is far to big to go into the bushing, looks like its the o ring for later style engines with nutted cranks (have no year based parts catalog only a 2000 and a 2003 which are clearly different.) there is clearly o ring marks inside of bushing, and it looks like at some point in its life the bushing was flipped because it has symmetrical polished marks inside of bush. I did not take engine apart and have no year specific breakdown, and manual i have is the generic one size fits all one everyone seems to have.
So is there actually a different thin oring which rides IN bushing? Has anyone seen this?
Help me please i have been staring at it for a couple of hours and all the info i have read mentions nothing of the type of seal.

any help is greatly appreciated

thanks
Asshat

Yes there is an O ring in there. It is part number ST950207 for the 200. You can used some 1000 grit sand paper to clean up the bushing. If the grooves are significant you can get a new bushing or if you are replacing the seal, you can drive it in a little less deep so it will ride on a different portion of the bushing.

http://www.manualslib.com/manual/386...00.html#manual

Zman thanks........
 

Zman. Thank you. I did see that pic in manual. Honestly I am not sure what I see. That appears to show a shouldered bushing inside of crank bearing? Isn't reference to the newer 2 style bearing?still confused? And feeling stupid. O ring sent to us was me250112011.

As I recall the crank has a shoulder that inserts inside the bearing. The bushing provides a replaceable wear surface. The o -ring seals the bushing to the crank shoulder I guess to prevent compression loss.

Zman thanks........
 

OK. This could be issue. I am using 2003 parts manual. Its closest to the 01.Shows only one number for o ring Which is same as 250 and 300. 2004 parts manual shows 2 different numbers. The one you gave me,(st950207) and me250112011. I have the ME o ring which must be wrong. No way I am going to get that in. Newer and perhaps larger engines show o ring against crank shoulder, then bushing on top. This one appeared to have o ring slid into groove ( only on 200 as seen on parts breakdown) then bush slid OVER o ring. Not compressed against shoulder as most appear to be. Makes sense. If you have right o ring.. I will order other o ring and hope its way smaller and I can slide bush over without peeling it out. The breakdowns are only for a reference I am realizing, and may or may not include info needed. All breakdowns show bolt holding main gear on, not circlip or even a part number. My other bikes have bolt holding gear on. Gasgas your killing me.
Thanks again
Gordon

Sorry my mistake. I took the number from a newer 2006 manual. I would use the O-Ring data you have from 2003. I suppose another option is to put a very light coating of oil resistant rtv on the face of the bushing and put it back together. I cant imagine it leaking with all of the force of the jam nut.

oring help
 

There is no jam nut. a circlip only. so rtv would not work and bushing on 01 200 is different than others. it is much lighter. and o ring runs inside of bushing not under. i will figure this out.
thanks for input
asshat

Im sorry I have not seen one like that before. The 2002 200 I rebuilt had the nut.