tmrperformance
Well-Known Member
got some useful info on your beloved zenoah engines once again!
so far i can name several builders that have had these cylinders fail, whether or not it was a cold seize on the piston in the transfer area, or a lean seize on the exhaust, or even a cracked base of a cylinder.. when the zen heads first came out a friend of mine had tipped me off and told me to watch the plating, if it looked spotted send it back! well till now i had not encountered that issue, but like i said until now.... well the cylinder i just ran was not ported, and did not appear to be blemished, and after a few pulls on the dyno my paranoia(lol) about these failing kicked in. i took the top end off to find my cylinder looking like a spotted leopard! there are tiny grey-ish spots everywhere!
needless to say i am not pleased with zenoah again!
i know im going to get crap for this but.... the cy 290's have gotten a bad rap for a while now but zen has cy beat in the failed cylinder department now! you say how is that?????? well lets think about this, the cy 290 came out how long ago??????????? and how many thousands were sold????????
and with all that time out you only here of one failing from time to time right??? well zen 36mm kits haven't been here 6 months yet and i myself have had 2 junks! not to mention all of the other people that i know of that have had them fail! to count off the top of my head i can name a total of 6 failed 36mm zens! thats not good odds for the time they have been available!
CLIFF NOTES: if u purchase a 36mm zen make sure you inspect it before installing it! you still may have a failure however if u spot something early you can possibly avoid having to make another top end purchase...
so far i can name several builders that have had these cylinders fail, whether or not it was a cold seize on the piston in the transfer area, or a lean seize on the exhaust, or even a cracked base of a cylinder.. when the zen heads first came out a friend of mine had tipped me off and told me to watch the plating, if it looked spotted send it back! well till now i had not encountered that issue, but like i said until now.... well the cylinder i just ran was not ported, and did not appear to be blemished, and after a few pulls on the dyno my paranoia(lol) about these failing kicked in. i took the top end off to find my cylinder looking like a spotted leopard! there are tiny grey-ish spots everywhere!
needless to say i am not pleased with zenoah again!
i know im going to get crap for this but.... the cy 290's have gotten a bad rap for a while now but zen has cy beat in the failed cylinder department now! you say how is that?????? well lets think about this, the cy 290 came out how long ago??????????? and how many thousands were sold????????
and with all that time out you only here of one failing from time to time right??? well zen 36mm kits haven't been here 6 months yet and i myself have had 2 junks! not to mention all of the other people that i know of that have had them fail! to count off the top of my head i can name a total of 6 failed 36mm zens! thats not good odds for the time they have been available!
CLIFF NOTES: if u purchase a 36mm zen make sure you inspect it before installing it! you still may have a failure however if u spot something early you can possibly avoid having to make another top end purchase...
