Side cover gasket issues

[68chevelle]

I have been running a modified clone motor in a race bike and keep blowing part 0f the gasket out of the side cover. Could this be an issue with crankcase venting? I am running maybe too small of a line out of the valve cover? or maybe the dowl's in the side cover are not allowing the proper seal of the cover.

What should be the size of the vent tube from the valve cover?

 

[JamnJM]

Try metric 10.9 grade bolts or studs yet?

 

[68chevelle]

I have not tried the stud kit yet...it might not work with my jack shaft plate mouted to the motor.

 

[JamnJM]

You mean that AGK plate jackshaft? Got a close up of it installed? I'm thinking of getting one for a modified Mini bike with a Minicycle rear swing arm and rear wheel combo.... :grind:

I have go from #35 chain to #40 chain with a jack shaft but both on the same left side of the bike.

 

[metalhead100]

Permatex spray gasket tack.......spray each side of gasket (hang it on a wire) let it dry 5-10 min.......install.......

 

[metalhead100]

could have a warped cover/crankcase too causing a spot with no pressure from the bolts....try a dry fit of the cover and look for voids in the contact around it

 

[68chevelle]

update: I pulled the cover off and inspected it...all looked good. Checked the dowl pins and noticed they were not the same size. This may have been the issue, so I removed part of the end to see if the cover seated better. I installed a new gasket and used a little honda bond gasket sealer in the problem area. Hope this works.

Attached picture of jackshaft setup. Yes it has been modified.

 

[JamnJM]

Thanks for posting that photo....is there a dbl bearing in that thick alum plate to support the sprockets?

 

[68chevelle]

Yes it has a double bearing. This is a new version made by GTC...very well made. I like it better than the old version.

 

[JamnJM]

I'm doing a Meyers lynx and thinking of using a 3/4" jack shaft with left sprocket outside of frame to clutch and rear wheel just inside that same area.....then I could make fast left side sprocket changes too.....:thumbsup:

 

[saychz316]

had the same problem on my first clone i built. went to side cover studs and vented my crankcase. problem solved.

get rid of the stock bolts if that is what you are using. studs are good! :thumbsup:

 

[Andrewp]

Can you post a few more pics of the bike? That chain tensioner is pretty cool.

 

[68chevelle]

Can you post a few more pics of the bike? That chain tensioner is pretty cool.

Check out this post for more pictures:

http://www.oldminibikes.com/forum/g...oms-frankenbikes-oddballs-200.html#post528406

 

[68chevelle]

Well I bit the bullet and added a new valve cover with duel vents...cost more than the motorut: added a new bolt kit to the side cover...hope she don't leak no more...