250R leaky base gasket ???

[3wheelrider]

Need some help here: Been runnin about 195 psi again and havin trouble with the base gasket again. Is this common when pushin compr. to that level?- Not sure if its pushing the gasket out this time? Hasnt been sucking air -just oily looking on the sides of the cyl. Occasionally a tiny bubble appears but thats it. ....My last base gasket did the same just only in one spot?-Ive run the piss out of this motor before and currently and never leaned out at all and had no lean symtoms but I would like to resolve this now before eventually ;) . I dont think the surfaces are uneven and theyre not gouged. Should I try a OEM base gasket?- Ive been using aftermarket (ATHENA,COMETIC,etc.) in which I have no luck with those headgaskets either.-(I have no issue with the OEM metal headgasket tho)..... Anyway, I havnt tried any sealer on the base gasket tho. -Also, Ive heard of using a punch to make dimples 3/8" or so apart on the bottom of the cyl.-should I try this?-Thnx for any suggestions

[ChrisD]

It should not leak even with 195. I run 225 on my 250 motor and have for years. You may not realize it, but your cylinder or cases could have warped. You would have to get it trued up again, but that will cost you some money and you may have to use two base gaskets when it's done.

I assume you are torquing the cylinder correctly....in stages, cris crossing as you go, then re-torquing it after break in time.

However, if you think you can get away with it, you can put a thin coat of High Temp RTV on the gasket where you have noticed the leaking. This is a back yard fix though and may not last forever.

[Dirtcrasher]

That thin part of the gasket is common to be sucked in on a healthy motor. 3 step of torque-ing it may not be enough and yes, it may not be perfectly flat on the 2 mating cases.

Every 2 stroke motor I rebuild I use a pointy punch and put 4 to 6 points in that area to help hold the base gasket.

It works as long as everything else is AOK.

[Poco Loco]

If you do use a sealer, Ive had great luck over the years with Three Bond. Its a hi grade lite silicone based sealer. Its a lil spendy but totally worth it.

I always use it on cases and the base gasket. I also use the spray copper coat on the head gasket. This is on the Gen III 250r.