Superjet compression

[Loganight]

Howdy, I have a 99 superjet 701 that Was completely stock with dual carbs and a type 4 dry pipe compression read 145~150. I added a Blowsion head with 37cc domes(calls for 165~ Psi) TDR waterbox, 9/15 hooker. My compression reads exactly 130 PSI on each cylinder and I can’t figure out why it’s so low. I rode it to seat the gasket and what not and re- torqued the bolts. I tested it with one spark plug in, throttle wide open, Brand new battery, and with a Snap- on compression tester with the correct adapter. If anyone has any ideas shoot them my way please. Thanks! I attached a picture as well

 

[Loganight]

Isn't this an O-Ring based Head? No need for a Gasket for these type Heads.

Did you use a Gasket? Then that would explain the Compression Drop...

Holy sh*t u got to be kidding me. Why thank you

 

[Jhucke]

Howdy, I have a 99 superjet 701 that Was completely stock with dual carbs and a type 4 dry pipe compression read 145~150. I added a Blowsion head with 37cc domes(calls for 165~ Psi) TDR waterbox, 9/15 hooker. My compression reads exactly 130 PSI on each cylinder and I can’t figure out why it’s so low. I rode it to seat the gasket and what not and re- torqued the bolts. I tested it with one spark plug in, throttle wide open, Brand new battery, and with a Snap- on compression tester with the correct adapter. If anyone has any ideas shoot them my way please. Thanks! I attached a picture as well

Hopefully you plan on figuring out a way to bolt up the two rubber isolators on that pipe, or you're going to have issues.