Super Jet How mutch compression is too mutch ???

[STOMPER]

Put an old greater yamaha head that i had laying around on my stock sj with pipe & msd ignition enhancer.the compression was 215 cold.must i run higher octane fuel,or will it be ok?i like to ride at full throttle!

 

[amitchell]

pretty sure 185 is the max you want on pump gas.

 

[txsuperjetfreak96]

it all depends on lots of stuff the jetmaniac/blue motors r running that compression and more on pump gas,

 

[JetManiac]

it all depends on lots of stuff the jetmaniac/blue motors r running that compression and more on pump gas,

not for much full throttle use though!

if you like to ride WFO much, then no more than 180ish.

 

[waxhead]

Depends on the condition of your compression gauge

 

[DAG]

what is your the bore and dome size?

 

[sjetrider]

WTFO = 185 max comp and no more that 25 degrees advanced timing is my rule of thumb
Freestyle no more than 195 comp and 28 degrees advanced
for pump gas 93 octane that is.
If you have an option of AV Gas you may be ok.