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Subaru EX21 low compression?

farmhard

farmhard

ArboristSite Lurker
Joined
Nov 2, 2019
Messages
37
Location
Buffalo, New York
Hi all, I have a 7hp Subaru giving me problems. Had spark, had lots of fuel. Oil is full and clean won't run. I went through the carb but it sounds like a Honda GX with bent valves hissing out vent into valve cover. Compression was 50lbs. Pulled covers, timing appears to be correct. Comp tested with rocker arms removed. 50lbs. Wet test 50lbs. Pulled head. Gasket looks fine, no carbon. Piston looks fine, no wobble, no scores. Valves are sealing. I did read these have compression releases but that should not affect testing with rocker arms removed.
Am I looking at rings????? Can't seem to find any info on these.

Thanks in advance.
 
frank_

frank_

ArboristSite Guru
Joined
Nov 5, 2019
Messages
672
Location
b/ham uk
the timing gear on the gx is only a pressfit on the crank eh (we used to shift it on the karts) maybe these are the same and it got very hot ?
 
farmhard

farmhard

ArboristSite Lurker
Joined
Nov 2, 2019
Messages
37
Location
Buffalo, New York
Hi Frank, Thanks for getting back. I checked the timing mark on starter with piston at tdc and cam timing was spot on. I guees I better pull the piston but the oil was clean, cylinder is perfect cross hatch and no carbon anywhere.
 
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