i just had my crank balanced w a venom 12.25 stock bore piston and im wondering if i can upgrade to a 480 pump gas piston without rebalancing? i weighed the stockbore if iu remember right it was 266 grams? sound right ??

i'll post the weight a bit later

not trying to rush you but i nee dthis info to order my new piston to get my build together

i forgot all about it with all the LTR dyno work i was doing....

so sorry...

stock bore 12.25:1 = 286 grams

480cc\97mm 12.25:1 = 297 grams


i will tell you this though..... switching from the stock brick in the 04-05 TRX's... to a much lighter aftermarket piston... there is no noticeable added vibration whatsoever...and there is usually at least an unbelievably HUGE 80gram difference there....

stroker cranks require re-balancing because of the huge amount of steel they take off the cranks for piston clearance @ BDC.....

the stock cranks are pretty much vibration free with a wide range of pistons sizes and compressions....

cool thanks for the reply, just to be safe im gonna see what crankworks thinks but ill def be calling for a piston in the next day or 2

just talked to crankworks and they said 10 grams is ok- 15-20 might be too much tho

oh yeah where should i send the cylinder to get bored???

milennium
max power
U.S. chrome

any of those places will do a great job

sent you a pm, i weighed both pistons and got different #'s


266g 450

295g 480

im pretty frustrated and out of $$ i may just bore the cylinder and run the + 30g piston and hope for the best

if you don't have a stroker , you will be fine...

the rpoble comes from the crank...not the piston weight