Super Jet cylinder compression issue

Ahmed AN9

Ahmed AN9

Location
KSA
I have a SJ 2009 with 85mm pistons and ADA non gridle head with 38cc domes using a pump gas. When I checked the compression i got (100 PSI) on both cylinders. What could possibly go wrong???
Note: The battery is fully charged.
 
Mike W

Mike W

Infidel
Location
North Florida
I would try another gauge. Due to the even compression the gauge would be suspect. If the compression was off in both cylinders I would be concerned.
 
Ahmed AN9

Ahmed AN9

Location
KSA
I really don't want to think about piston-cylinder issues. So, check the compression with another gauge will be my first step.
 
X

X2Kid

Location
Canberra, Australia.
If the 'ski starts readily and makes good power I would suspect a faulty gauge. Below about 120 psi compression they get really hard to start and have no power. At a genuine100 psi it would be a miracle if it ran at all...
 
Blue

Blue

Judging your cheapness
Location
St Cloud Florida
Possibly its a 760 cylinder some one swapped out?? 84.5mm is max on a 61x cyl and thats paper thin but i have seen it done. Not by me though. Sleeves sometimes drop causing the ADA head orings to blow out. But try a different guage before taking it apart just to be sure.

Sent from my SAMSUNG-SM-N920A using Tapatalk
 
augustaf

augustaf

Location
central florida
Your ada head uses "deep reach/long" spark plugs. Your compression gauge needs to have the same length, otherwise you'll get a low reading (several cc's difference)P1020857.JPG
 
Funky Blaster

Funky Blaster

Location
Nor Cali
When was the last time the topend was rebuilt? Since you have the head off, what do the cylinder walls look like?
 
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