Hi my saw blew up about a month ago so i have ordered a new meteor piston and jug, I'm waiting for it to come from the states. So whilst I have been eagerly awaiting the new parts I have been modding the muffler and practicing windowing the piston. what do you think. I am welding the exhaust tomorrow any hints or tips whilst i'm doing these mods....I don't know anyone in the UK who has been doing the mods like you guys. Whats the easiest way to wash all the aluminium particles off everything once its ready to re-assemble? I don't want to rush this project and would love to have a saw rivaling some of you guys across the pond!
re-building my 362/372 xp hybrid
- Thread starter benjy
- Start date
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SawTroll
Information Collector
You need to find out why the old top-end failed, and fix the issue, before you put a new top-end on the saw! :msp_wink:
The windowed pistons generally come with the closed port engines where the lower transfer ports enter into the side of the cylinder wall.
With the 372, the lower part of the intake transfers have their own entrance directly into the crankcase. Therefore windowing the piston serves no real purpose other than making the piston lighter.
With the 372, the lower part of the intake transfers have their own entrance directly into the crankcase. Therefore windowing the piston serves no real purpose other than making the piston lighter.
UK Rich
ArboristSite Operative
Good man. I'm the 'southern fairy' on here now then... Cheers!
Me mod my saws? Yeah most of them - Not as much as some of the dudes here, the wife wont let it.
was straight fueled by my dad :S
UK Rich
ArboristSite Operative
parrisw
Tree Freak
Sounds awesome that way! One of mine is like that. Love it.
i'm hoping so! i saw the thread you linked for me in a different post of mine. thanks for the help i appreciate it!
Logger4Life
ArboristSite Operative
I agree with the statement from above there is no reason to window the piston it will just weaken the piston and believe me you do not want to have a piston come apart at 14,00 rpm showing off to your friends and the next thing you now bang and out comes the rod though the case. It will rev plenty quick and have tons of snot just ask Parrisw or Mastermind for some timing # that work for that combo I would ask Mastermind because he has been playing around with thoses Metror kits so he is the expert for this question. Set your squish and screaming you will be .
ok thanks for the advice on the windowing.. i guessed it might just be another thing to F**ck up. Parrisw has been great already but i shal seek further advice! thanks
parrisw
Tree Freak
My 372 with that same muffler mod has had the piston windowed, no problems yet.
parris can you give me the machining specs of your pop piston?also the timing numbers? or anything else i will need for saw like yours? if i could buy you a beer i would but i cant so this will have to do! 
parrisw
Tree Freak
parris can you give me the machining specs of your pop piston?also the timing numbers? or anything else i will need for saw like yours? if i could buy you a beer i would but i cant so this will have to do!
You really need to do some measurements. But that one has a .030" popup, .020" squish. I think, 160* int and ex duration, 20* blowdown. It's all in the thread of that saw. I'll find the link.
