Rebuild

[biggdadd]

Hi, I realize this is my first post here and I am at a roadblock in the rebuild of a Banshee. I have had both cylinders bored with new piston kits, replaced the crank with a new one along with bearings and seals. Everything seemed to go together well but the compression was below 80psi. It will run if you pull start it and seems to run fine but will not kick start.

 

So, split the cases again to double check to see if something might have not been done correctly. The case halves were bonded together and the seals seemed to be ok. Replaced everything including the reeds and only gained 10lbs of compression, up to 90lbs. I have rebuilt many motors in my time and this is the first time that I have been stumped.

 

Any input would be greatly appreciated.

[sheefreak]

You didn't replace a Stroker crank w/a stocker did you? Do you have zero dech height or near? Are your domes recessed at all?

[68chevyc10355]

Was the compression at 80 psi immediately after rebuild? (No running time at all?) Also, are you sure you have the correct pistons and rings.

[Jereme6655]

what kind of pistons did you rebuild with? did you have it bored/honed or did you just slap some pistons in there?

[Jereme6655]

and what fuel mix are you running?

Edited November 20, 2010 by Jereme6655

[biggdadd]

The pistons were Wiseco and the cylinders were bored to match. The clearance between the wall and the skirt are to specs. The crank is not the issue. There pistons come to the top of the cylinders and the head is stock. The fuel ratio is the 32:1 mix and the reeds sit flat on the cage.

 

This is the first banshee that has given us this problem and there is not a clear answer that we can put our finger on as to how to fix it. The bike came to us with a locked up crank. The cylinders on the exhaust ports seem to be really tall but it doesn't show the signs that they were ever ported.