Spyder John
04-22-2008, 12:56 PM
After blowing out out a head gasket on my Aisal 70 I noticed a spot at the top of the cylinder where the nicisal was eroded through, presumably from preignition at the spot where the unnoticed leak was until it finally blew out. I order a new Aisal from Provo, or so I thought. What was a KRS kit. I wasn't really happy but I assumed that it was comparable. The shape of the ports is different but the overall size looked about the same. Didn't measure the hight of the ports, although I probably will because I think port timing may be an issue as well.
Bottom line is, I can't get it tuned with my setup. Way too rich at lower RPMs and lean at the top. I can't get it lean enough with the air screw and needle to even rev up unless the main is disastrously lean. Just for yucks I stuck the old Airsal barrel on and it runs fine (95 main, needle in the middle, air screw out about 1.5 turns)
Anyone have any ideas? I don't really want to just run the questionable Airsal, not only because of the nicked liner but I'm sure I'd have to home it to get the rings to wear in properly.
FYI I'm running a Mikuni 17.5mm carb and a Gianelli NRX pipe. This setup worked (works) fine with the Airsal, so easy to tune that I can vary jetting, needle hight, and airscrew setting either way and still have a runnable setup. With the new cylinder there's nothing I can do to get it to run right.
Any ideas?
Bottom line is, I can't get it tuned with my setup. Way too rich at lower RPMs and lean at the top. I can't get it lean enough with the air screw and needle to even rev up unless the main is disastrously lean. Just for yucks I stuck the old Airsal barrel on and it runs fine (95 main, needle in the middle, air screw out about 1.5 turns)
Anyone have any ideas? I don't really want to just run the questionable Airsal, not only because of the nicked liner but I'm sure I'd have to home it to get the rings to wear in properly.
FYI I'm running a Mikuni 17.5mm carb and a Gianelli NRX pipe. This setup worked (works) fine with the Airsal, so easy to tune that I can vary jetting, needle hight, and airscrew setting either way and still have a runnable setup. With the new cylinder there's nothing I can do to get it to run right.
Any ideas?