new piston

[mad4106]

Hey guys im overhauling my bike i had a 11:1 wiseco piston piston with a curtis sparks exhaust and stage 2 hotcam i want to drop the compression down to a 10:1 or 10:5:1. I want my bike to be more reliable any suggestions on piston size its standard bore by the way? i dont wanna lose too much power is their any better brand yall would suggest?!

[ridehonda400ex]

do 10:1, stg 2 hc and a sparks timing key, will need at least 93 gas and wouldnt hurt to mix some 100 in there

[4WheelinDemon]

i have a 10.5:1 compression in mine. It all depends on what your going to use the bike for and how frequent will you be riding it? are you using it mainly for racing? or just to cruise around on? if your raceing it, then go with the higher compression. If your just going to use it to ride around on and your going to be using it frequently, go with the lower compression. lower compression will give your top end a longer life, higher will of course shorten the life. basically it all depends on what your using it for.

[CJM]

11:1 is plenty reliable, I run it and so do many others. I wouldnt drop it down unless you need a rebuild.

Key to being reliable with hi-comp-JET IT RIGHT. To lean and you will burn it up. Hi compression is where the power is.

[Pipeless416]

Agreed with CJM. also, you do NOT need to mix 100 octane for 10:1 :o . That's just throwing money away.

[mad4106]

Thanks guys with 11:1 with the standard bore which is 85 can u still run 93 pump gas? thats wat im using

[Pipeless416]

yes, but if you don't mind me asking, why is it still going to be stock bore? it should at least be cleaned up since it's most likely a little out of round.

[CJM]

Yes, Pipeless is right: You need to go up .5-1mm or so b/c by now your bores probably outta round-at least hone it otherwise if you already bought the piston. This would ensure a good sealing surface for the new rings. Also, make sure to gap the rings properly when installing-it will make a world of difference.