high comp. pistons [Archive]

super90

01-20-2008, 02:21 AM

My 200x is starting to smoke a little and Im looking into getting a 10.5:1 high comp. wiseco piston for the rebuild. How much more can I expect from it? Will it be gaining any speed or mostly mid. range power and torque? Also what kind of fuel should I be running? I know the 12.5 compression pistons you need race fuel and could grenade your engine, but how reliable would a 10.5 be for trail riding? :wondering

TeamGeek6

01-20-2008, 02:38 AM

Mostly depends on the crank/rod bearings and ignition system. Stock ignitions dont work well with high compression.

350xrider911

01-20-2008, 02:45 AM

tell us more im running the same but in 350x and its smoking

SWIGIN

01-20-2008, 02:49 AM

10.5 is perfectly fine and pump gas friendly

super90

01-20-2008, 03:05 AM

My engine is pretty solid, im almost positive its still on the origional bore and has never even been tore down except by me. Hopefully the cylinders not worn and needs bored out. This is the first time im rebuilding a 4 stroke engine so I dont know a whole lot about the top end. How would I know what bore its on and the size of the piston? Im having a friend help me do it, but im just curious myself.

MTS

01-20-2008, 08:56 AM

My engine is pretty solid, im almost positive its still on the origional bore and has never even been tore down except by me. Hopefully the cylinders not worn and needs bored out. This is the first time im rebuilding a 4 stroke engine so I dont know a whole lot about the top end. How would I know what bore its on and the size of the piston? Im having a friend help me do it, but im just curious myself.

Take it to a shop, have it Bored/honed for a new wiseco, cut the rigs, or you will seize it up quick

Liquid-Darkness

01-20-2008, 11:19 AM

Yeah Super90 your best bet is to pop the top. Take the jug down to your local machine shop or mechanic that does bore work. Mike it and buy a piston kit of your choice. Then have it bored out for clearence. Lap the valves on your head and replace the valve seals. Then you got a like new topend. 10:1 runs great on premium. 12:1 requires some race gas. I am running a wiseco bored .040 over 12:1 piston and can run 50/50 110 race gas cut with premium and it runs great with my 86 350x.