I have a new-to-me NSF9.9B, serial 10430, shortshaft estart tiller. I have had several 4/5/6 4-stroke Nissans, but this is my first twin cylinder. I don't yet have a service manual, but will get the factory one soon.
Checking everything over before I go and try to start. It only cranked over 1/2 turn with the pull start when I was buying it, but I found out someone had laid it down the wrong way and the bottom cylinder was full of clean oil. I pulled the plugs and pull-cranked it to clear out the oil, then put the plugs in and it appeared to have compression in both cylinders (just from the pull starter effort).
Getting it home, I checked compression in both cylinders. Bottom one was 180+ but the top one was <50. I was using the estart to crank. Used a leakdown tester and the top cylinder had 8% leak and it was leaking out the intake. Bottom cylinder was ~2-4% and no obvious leak any direction.
I'm not 100% sure I was at TDC though.... if the dots (one per cylinder) on the cam gear are pointed towards the crankshaft, is that the right spot for TDC for each cylinder?
I am going to pull the carb to clean it, not knowing how dirty or clean it is but especially because of the oil issue.
Can you pull the cover to check out valve clearance without removing the powerhead? Any other model-specific suggestions or known issues that would cause a cyl #1 (is that the top cylinder?) issue?
Also... when laying these engines down, is it the same as the 4/5/6 series... only lay down on the handle side?
Checking everything over before I go and try to start. It only cranked over 1/2 turn with the pull start when I was buying it, but I found out someone had laid it down the wrong way and the bottom cylinder was full of clean oil. I pulled the plugs and pull-cranked it to clear out the oil, then put the plugs in and it appeared to have compression in both cylinders (just from the pull starter effort).
Getting it home, I checked compression in both cylinders. Bottom one was 180+ but the top one was <50. I was using the estart to crank. Used a leakdown tester and the top cylinder had 8% leak and it was leaking out the intake. Bottom cylinder was ~2-4% and no obvious leak any direction.
I'm not 100% sure I was at TDC though.... if the dots (one per cylinder) on the cam gear are pointed towards the crankshaft, is that the right spot for TDC for each cylinder?
I am going to pull the carb to clean it, not knowing how dirty or clean it is but especially because of the oil issue.
Can you pull the cover to check out valve clearance without removing the powerhead? Any other model-specific suggestions or known issues that would cause a cyl #1 (is that the top cylinder?) issue?
Also... when laying these engines down, is it the same as the 4/5/6 series... only lay down on the handle side?