low compresion

[longmont]

i just cheaked my compresion and it was real low 90 i was wondering how to tell if i am going to need to bore out the sleeves or if i could put stock pistons in. the sleeves dont look bad no scratches or anything the pistons measure 64 mm how much performance will i get by going with a larger set of pistons and with putting new pistons in is it going to fix my compresion problem

[gregrob]

i just cheaked my compresion and it was real low 90

 

Did you hold the throttle wide open? Did you kick it until the needle stopped moving?

 

i was wondering how to tell if i am going to need to bore out the sleeves or if i could put stock pistons in.

 

You need to have the cylinders mic'd (measured with a very precise tool) when you take them apart. That will tell you if a stock bore size piston will be in spec or if you need to go bigger. More than likely you will need to bore it one size .020 over and get a .020 piston kit.

 

the sleeves dont look bad no scratches or anything the pistons measure 64 mm how much performance will i get by going with a larger set of pistons and with putting new pistons in is it going to fix my compresion problem

 

 

Very little gain to be had from a small overbore. Some, but not a lot. Stroke is where it's at.

 

New pistons and new bore with properly set tolerances will cure your low compression woes.