mag piston looks the best out of all of them, as it shows the wash marks and good even coloring. so whatever the jetting is in that cylinder you should duplicate to the others. What year is the ign system on this srx engine?
how come you have a aftermarket piston in the mag and yamaha pistons in the center and mag? You need to ditch those stock wristpins too and put in some lightweight ones.
how come you have a aftermarket piston in the mag and yamaha pistons in the center and mag? You need to ditch those stock wristpins too and put in some lightweight ones.
take the pto piston off and look on the bottom of the piston dome should be chocolate brown if its black and burnt then its lean
Wait………what ??? Your reading the bottom of your pistons?
YAMMIEGOD3:16
Active member
i will say close. possibly a tad more jetting if your making long pulls. i don,t like mix/matching pistons. 3:16 (yammie tony)
hey don i did u know i had different piston.. i didnt know myself lolll...how can u tell that from a photo ????...the curious things is the mag cylinder run 155 and the two other run 158.8 ...the ignition is a 2000-up system that i put on a 98 motor ..i weld the trigger closer still not sure if it well at the perfect place for timing
just looking at the picture i did realise ....i guess that piston was in my box and didnt realise the difference
Absolutely, theres a good sign of whats happening on the bottomside of the piston as well, Ron is right on the money!!
check the tech section for the piston wash reading, theres pics there of what Rons referring to!
Absolutely, theres a good sign of whats happening on the bottomside of the piston as well, Ron is right on the money!!
check the tech section for the piston wash reading, theres pics there of what Rons referring to!
Thanks, good to know. I've only read the tops.
DOes the mid and pto cylinder look lean ? why u ask about the ignition don
I can tell because its stamped with "std" thats not for sexually transmitted disease...LOL, it means standard bore which the yamaha pistons do not have. Also, it has no arrow for exhaust, and it doesnt have the center round bump that the stock yamaha pistons have where they are parted from the forging.
I asked about ign system because the mag cylinder lokks the best, on a 98-99 engine the mag runs the hottest so it needs the larger jet placed in the mag instead of the pto as the 2000-02 srx is.
Are the needle settings all the same on all 3?
pilots the same?
have you ever checked the squish to see if its the same in all 3 cylinders?
same compression numbers in all 3?
Needle are set all the same .. PIlot are 45 ,compression all the same all across , the only thing I could see is the air box that doesnt fit the same way under the viper hood since i change the hood.but I just buy one from a viper I will see if something change ...
hey don do u think the aftermarket piston can have different dome angle
jetting is 155 153.8 153.8 ....I will raised them some
put 156.3 viper main jets in all 3 and ride it and forget about it!