Hi guys, well after our third race we suffered our first engine damage. And the worst part is that is all caused from the failure of a 50 cent rubber vacuum cap! I have the new Titanium reed cage/intake, and I put a threaded plug in place of the smaller vac. fitting, but just used a rubber cap on the larger fitting. Well I didn't know it but it cracked and after last weekends muddy races we have only 150 psi compression instead of the 195 we started with. Found gray gritty stuff inside of the ports and on top of the piston. The cylinder looks good, only noticible mark is where the ring gap is... The airsal kits come with a single ring piston. I washed out the crankcase with the mixed gas we run, and am hoping the bottom end is ok. Has anyone ever ran one of these 52mm aluminum airsal kits on a 90 and can you tell me if I can run a WISCO piston kit in it???? The only obvious visual wear we suffered is on the piston skirt. No scuffing or grooves, it is just worn smooth, so that the machining grooves are gone. And can I lightly hone the cylinder so the new rings will seat or is the nikisil lining too thin??? Please help!!! P.S. I noticed the Airsal piston doesn't have the piston ports in it like the stock piston, but the cylinder ports are all in the same positions????

 

Get a stock or wiseco piston it will work and do not hone the airsal cyl the coating will be destroyed. Yes the piston ports help topend power.

 

have you used the 52mm airsal cylinder kit??? Lakes motorsports says to use the airsal piston... better performance. And he also said that i can hone the cylinder. Not sure what to do, the cilinder looks fine... only slight wear, but I would think at least a light hone would be better than not at all. Thanks.

 

My opinion is that most engine builders would not tell you to hone a nicasil coated cylinder. Get a second opinion before you hone it call Rich at Hetrick Racing or Billy at WRH racing.

 

do not hone the nicasil, anybody who builds engine would tell you NOT to hone it, it will ruin it.

 

Thanks guys, I will try billy holt and see what he says.