1989 Johnson 40hp running on one cylinder

[Tubes66]

So I rebuilt the carbs and checked spark and everything looked good , has all new fuel line and no leaks , compression is 90 lbs in both cylinders and have been messing with it to get it to run right and noticed that it's not running on the bottom cylinder. What could it be it's definitely getting fuel has great spark and has the same compression as the other cylinder

 

[Tubes66]

Oh and the reed valves look fine

 

[racerone]

Compression is way too low.----My gauge would show 140 on one of those motors.---Bottom crankshaft seal checked ?-----What happens when you spray some fuel into the bottom carburetor ?

 

[Tubes66]

Spray staring fluid in the bottom carb when running and it does nothing , and how do I check the crank shaft seal . Even without spraying starting fluid and pulling the bottom plug after running the plug is super wet so it's getting fuel .

 

[Little Richard]

How are you checking your spark are you sure it's good

 

[Tubes66]

Gap tester

 

[Tubes66]

Could really use help!! Trying to get it going asap

 

[Little Richard]

So spark is jumping 7/16 inch gap. Strong and consistently. Do you have a timing light where you can confirm cylinders are firing and at the right time.

 

[Tubes66]

I'm going to try a 7/16" gap tomorrow, how do I check timing , never done timing before ...

 

[Tubes66]

And what spark plugs should it have in it? It has ngk plugs in there now

 

[Tubes66]

And 90 psi was the compression test after it had been running

 

[racerone]

Check crankcase compression on bottom cylinder.-----I would remove cylinder head for inspection ?----Head gasket is cheap.

 

[Tubes66]

how do i check crank case compression?

 

[flyingscott]

Pull the head off like racerone said.

 

[Tubes66]

So I was just messing with it and noticed and a little higher Rpms then idle the cylinder starts to hick up and fire a little bit

 

[racerone]

What does " messing with it " mean ?-----What did you do ?

 

[Tubes66]

Spark is jumping the 7/16 great ..... really stumped . What is pulling the head off gunna prove

 

[Tubes66]

Also Is there points under the fly wheel?

 

[Tubes66]

Messing with it meant starting it and reving it up seeing if it would run

 

[Tubes66]

I really wish it would let me post a video to show how it's running