need help getting my engine to fire

[Kev55]

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?

[Phelps]

not enough compression.....

 

are you still running the head/domes for the big bore cylinders?

[Kev55]

yeah i'm using the same head. what should my compression be at?

[Phelps]

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.

[Kev55]

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

[Larry's Shee]

Need one that screws in , adapter same length as plug threads.

[alf44]

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.

[DallasGDub]

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)