Kev55 Posted September 11, 2010 Report Share Posted September 11, 2010 I just finished rebuilding my engine and went from size 67mm back down to 64.75mm cylinders. So I dropped the engine back into the shee and try to get it to start but I'm getting nothing... I checked the compression and its like 60psi on one and 67psi on the other. I'm getting spark. So I'm guessing it has to be fuel. I'm thinking that the carbs need to be tuned because of the now smaller cylinder size but I would have thought I could at least get it to fire or just run like shit. anyone have any ideas? Quote Link to comment Share on other sites More sharing options...
Phelps Posted September 11, 2010 Report Share Posted September 11, 2010 not enough compression..... are you still running the head/domes for the big bore cylinders? Quote Link to comment Share on other sites More sharing options...
Kev55 Posted September 11, 2010 Author Report Share Posted September 11, 2010 yeah i'm using the same head. what should my compression be at? Quote Link to comment Share on other sites More sharing options...
Phelps Posted September 11, 2010 Report Share Posted September 11, 2010 yeah i'm using the same head. what should my compression be at? 110-140 depending on your elevation. if you have a stock head i would suggest putting it back on. Quote Link to comment Share on other sites More sharing options...
Kev55 Posted September 11, 2010 Author Report Share Posted September 11, 2010 im pretty sure the head is stock but I'll check again when i get the chance. the gauge could be faulty too, the rubber end that you push in the spark-plug hole is pretty old and cracked. thanks for the input Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted September 11, 2010 Report Share Posted September 11, 2010 Need one that screws in , adapter same length as plug threads. Quote Link to comment Share on other sites More sharing options...
alf44 Posted September 11, 2010 Report Share Posted September 11, 2010 A good tester is definantly a must. You need to kick it about 30-50 times to get a good reading and get the compression up where it needs to be. If its not sealing your not going to get the right reading. Quote Link to comment Share on other sites More sharing options...
DallasGDub Posted September 11, 2010 Report Share Posted September 11, 2010 the gauge could be faulty too, the rubber end that you push in the spark-plug hole is pretty old and cracked. My tester has an end that you screw into the whole just like you would the spark plug. I agree, check the tester. (even if it is low, better off knowing for sure) Quote Link to comment Share on other sites More sharing options...
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