Well lets start out by telling you what I have. I have a 1997 banshee with Tony Dukas port work, trued and welded crank, cool head with 18cc domes, over ride tranny,and this thing screams it runs really good. I am running a 15-41 gear ratio.BUT I only have 100lbs of compression. I took the head off and every thing looks fine. Can someone tell me what is the deal hear.

 

When the last time you had top rebuilt?

How often do you ride the bike? If you ride alot and have not had a top rebuilt for several yrs. Then it might be time to do it.
The ring might be a little worn...

 

The top end is brand new. New piston and rings. We went and rode yesterday and this thing is awsome. I am about 300lbs and it is pulling me out of second like a rocket. Anybdy got any suggestions.

 

LEAVE IT ALONE. It runs good enough. [img]i/expressions/face-icon-small-tongue.gif[/img]

Thats just my 2 cents worth.

 

Did you have the throttle wide open when you were checking the compression?
If you don't hold the throttle wide open you can't get air in to the cylinder to make any compression.
Since it sounds like it's running good that is what it sounds like you did.

 

your rings could be stuck, bad reeds, REALLY big exhaust port. i'm not for sure if a bad O ring would cause it.


is both cylinders the same? are you sure the gauge is right? try it on another bike.

 

Thanks..

 

Dsmike is on the right track... Porting lowers your compression since the exhaust ports are raised... How much depends on the port job. The 18cc domes should increase your compression a LOT But again, depending on the porting, it's hard to say what your compression should be.

If it starts easily the the compression isn't so low as to give you a problem.... Hard starting is a sign of too low compression.

Is the compression gauge good - can you test in on another machine or try a new gauge. Make sure you hold the throttle at full and kick several times until the reading stops getting higher. And check both cylinders.

The main thing is that it runs strong.

 

Well it runs and starts good. So I guess I will leave it alone.