Next step? HELP!!!

[Rollin668]

Well, I tested the bike out after installing new fuel lines, a high-flow fuel filter, and the fuel shut-off valve... still the same problem.  It will run great for about 15 minutes or so and then it will lose power... almost dying and in some instances dying.  I will start back up but with a small amount of throttle and RARELY with the choke...

What would the necxt suggestion be to figure this one out?  The shop I had it at said the bike was fine other than needing a tune-up, but would the need for a tune-up cause symptoms like this?

HELP!!!!!

[Rollin668]

I noticed I have an oil leak on the "shifter" side of the engine... looks like it's seeping out from the case.  

Anyway, I am thinking that there must be some space between the case and the engine if oil is getting out - if an engine needs to be pressurized, then would it lose power if air was getting in the engine?

Maybe the air is getting in after I run the engine for a bit because the oil is getting thinner or the case is just moving away from the engine?

Hmmm... there must be a gasket between the case and the engine right?



Rolly

[Pkaaso]

Well lets see.  

Yes, there is a gasket inbetween the case and the engine. There are two cases on that side.  The front one has oil behind it the other is the sproket cover.  If it is leaking from here, it may be the shifter rod coming out of the engine case.  There is a seal there.  Try to determin where the oil is comming from. You can remove the Sproket cover (the one that has the clutch cable going into it) with out loosing oil.

Or,  It may be leaking from the gasket on the front case cover.  Have you tried to tighten the case bolts? (Don't over tighten they will break).  The engine oil will not thin enough to leak unless the gasket is going bad.  It most likely will need a new gasket.  You can get away with leaning the bike over and replacing the gasket with-out draining the oil.  Bob B. taught me that one.

The engine is not pressureized.  I has a blow by hose at the top of the valve cover - Make sure this is venting properly.

You other problem sounds like fuel flow problem.  I had a similar problem.  I took off the tank and noticed that while trying to drain the tank (hoses removed) the fuel was running very slow.  I checked the  filter screen by removing the pet chicken in the tank.  It was clear but fuel still flowed slowly.  I replaced with a petcock from another tank and then it was flowing strong from both res and on connectors.


Most racers do away with the selector and replace the tank petcock with a Pringle petcock and run the line directly to the carb.

It also may be the floats not being set correclty.  This will cause the engine to starve out after a few minutes of running open throttle.
There is a very easy way to check your fuel level in the bowls with a 1 foot peice of model aircraft fuel line hooked up to the drain on the bowl.  You open the drain screw and hold the hose up - the level should be right at the joint between the float bowl and the carb body.

Hope this helps a little.  Others will jump in here with more help I'm sure. Stand by,
Paul

[Kerry]

There is a very easy way to check your fuel level in the bowls with a 1 foot peice of model aircraft fuel line hooked up to the drain on the bowl.  You open the drain screw and hold the hose up - the level should be right at the joint between the float bowl and the carb body.

You may have already done this, but here's a page with pictures just in case.

EDIT: Changed link from sisna.com to bbburma.net

[Pkaaso]

It was late and I couldn't remember who I got that idea from.

Credit where credit is due.  

Thanks Kerry.