Vector88
New member
hey
did anyone ever try the SPI pistons in a viper? im planning on rebuilding my motor next week! new pistons, needle bearings, rings, and wrist pins! got it on the way as we speak! my friend has SPI piston in his middle cylinder on his mountain max and the other 2 cylinders have the orignal stock OEM pistons from yamaha. he said they seem to work great! well anyways, im going to rebuild the top end on my viper. oly planning on ding this because i have low compression compared to normal! 100 on the PTO cylinder and 110 on the middle and mag cylinder. after the machien is warmed up i got to hold the throttle to get her going because she wont get started until i haul 3 or 4 times. my viper has almost 8400 km on it now. put about 1500 km on in 1 month! i say some of you guys dont get that much all winter! lol well any help or recommendations would be great!
did anyone ever try the SPI pistons in a viper? im planning on rebuilding my motor next week! new pistons, needle bearings, rings, and wrist pins! got it on the way as we speak! my friend has SPI piston in his middle cylinder on his mountain max and the other 2 cylinders have the orignal stock OEM pistons from yamaha. he said they seem to work great! well anyways, im going to rebuild the top end on my viper. oly planning on ding this because i have low compression compared to normal! 100 on the PTO cylinder and 110 on the middle and mag cylinder. after the machien is warmed up i got to hold the throttle to get her going because she wont get started until i haul 3 or 4 times. my viper has almost 8400 km on it now. put about 1500 km on in 1 month! i say some of you guys dont get that much all winter! lol well any help or recommendations would be great!
mopar1rules
Active member
I wouldn't be doing what your buddy is doing....running 2 different brand pistons. they won't weigh the same. will be a little out of balance. my .02 I guess. you shouldn't have any problems running the spi pistons. they are a popular piston I know for ski-doo's and probably the other brands.
Take some measurments on your pistons. They may be within spec and if so just re-ring your motor. Most people recommed the stock pistons in the yamaha's. I rebult my SRX at 14,000 kms and just did the rings as pistons were fine. Here is a website for a company that has great prices on stock Yamaha parts. Prices are on site as well. http://www.cyclepartswarehouse.com
Sorry, just noticed that you already ordered your stuff. They will probably be fine if your changing all three.
Vector88
New member
also, after i get the sled goin after i press the throttle as i haul she will be good. and there is no problems with the carbs! she idles at 1500 rpm like normal. i say its time for me to rebuild the top end on this motor.
Vector88
New member
ya they will probably do fine if not ill get genuine yamaha!
Vector88
New member
anyone know why she is so hard to start just after shuting the engine off? my viper is real easy to haul over compared to my buddys mountain max 700. sometimes it takes 4 hauls and it starts the first haul when i press the throttle while a haul. but sometimes she dont act like this! anyone?
mopar1rules
Active member
you should clean the carbs while the top end is off. you can do the carbs before your pistons come.
lol, you can pull all day or just give it 1/16 throttle and it will start right up. totally normal for a yamaha triple.rx-1mountain said:
mopar1rules
Active member
YamerDown said:
X2.....