1992 Johnson 15 hard starting

[nation99]

A friend asked me to look at this motor. It hadn't been run in several years. I removed the carb and "cooked it out". Put it bac on and replaced a broken linkage part. It runs great once I can get it started, but it is VERY hard starting either cold or hot. Plugs look good and gas is new. Any ideas where I should be looking for this problem? Thanks!

 

[racerone]

Model # is ?-----Post the compression test numbers here.-----So when you pull the choke does the flapper close and stay closed ??-----Are you turning the throttle handle against the neutral stop for starting???

 

[nation99]

J15RLENM. I don't have compression numbers at this time...seems to be pretty good just based on the effort to pull the starter rope, but I know that is very subjective. I'll have to look at the choke. I know it closes, but I never looked to see that it stayed closed. Yes, throttle is in the start position. Raining here today so I'll check further tomorrow.

 

[racerone]

You ignore the marking on the grip.----You turn the grip till it hits the neutral stop !

 

[nation99]

Got it. that is what I've been doing, but I will try again tomorrow and check that the choke is staying closed.

 

[nation99]

You ignore the marking on the grip.----You turn the grip till it hits the neutral stop !

OK, I looked at it again today. My observations are as follows.
Seems to start better when cold.
Throttle must be tight against the neutral stop.
When running at low speed the RPS will vary quite a bit.
Big one: compression is 50psi in one cylinder and 70 psi in the other!

I assume we are looking at bad valves, bad gaskets or scored cylinders. Your comments please! Thank you

 

[racerone]

Valves have nothing to do with compression in the cylinders.----Take cylinder head off.

 

[saltchuckmatt]

OK, I looked at it again today. My observations are as follows.
Seems to start better when cold.
Throttle must be tight against the neutral stop.
When running at low speed the RPS will vary quite a bit.
Big one: compression is 50psi in one cylinder and 70 psi in the other!

I assume we are looking at bad valves, bad gaskets or scored cylinders. Your comments please! Thank you

Put some wd 40 in the cylinders and turn the throttle wide open and run your test again. Make sure you pull it 5 to 8 times or so. Those reading are no good so check your work. Otherwise, yes pull the heads and hope for a bad head gasket. Most likely she toast.

 

[racerone]

Throttle does not need to be open for a compression test on this motor.

 

[nation99]

Put some wd 40 in the cylinders and turn the throttle wide open and run your test again. Make sure you pull it 5 to 8 times or so. Those reading are no good so check your work. Otherwise, yes pull the heads and hope for a bad head gasket. Most likely she toast.

Retested today. Results are #1: 60psi & #2: 78psi. I squirted some oil in the cylinders and retested. #1: 120psi & #2: 100psi. Most likely bad rings??

 

[nation99]

Throttle does not need to be open for a compression test on this motor.

Retested today. Results are #1: 60psi & #2: 78psi. I squirted some oil in the cylinders and retested. #1: 120psi & #2: 100psi. Most likely bad rings??