1960 johnson 18hp no power

[oldboat1]

?? Don't hurt anyone.

 

[lindy46]

Well I’m done with this motor. I put new j4c plugs gapped to .030. I took filter out. Filled the bowl up with gas. Started up seemed to run good at idle. Go to full throttle and it’s loading up with heavy blue smoke everywhere. I even squeezed the bulb to see if that made any difference and it didn’t so I assume the pump is fine.I tried turning high speed needle to the right to lean it but no luck. I took bottom plug off and it would stay running but obvious difference. I took top off and it died. Whatever that means. I’m no dummie and I’m very mechanically inclined but this has ticked me off. All my 13 year old son lives and breathes fishing and I can’t. Anyways other than getting another carb there’s nothing else to do.

It means the bottom cylinder is not firing for some reason. If you have spark, compression and fuel, it should be running. What about plug wires - are they new? It could be old wire is grounding out when connected but when you move it to connect the spark tester, it's not grounding out.... just grasping at straws now.

 

[racerone]

For some folks a new motor is the best option.

 

[dbechtel71]

if i could afford a new motor i would have by now lol!!! i can go get another johnson 18 hp that supposedly just needs an thermostat or improperly installed impeller but do i want another head ache? the plugs wires boots and metal contacts are all brand new. when i take the bottom plug off the motor wil stay running but i definately noticed a drop. when i took top plug off it stalls completely.

 

[racerone]

The motor sounds like it is running on 1 cylinder.-------Orderly trouble shooting on this simple motor must be done.-----What does a compression test show ?-----Checked reed valves ?

 

[dbechtel71]

90 psi in both. where are the reed valves?

 

[dbechtel71]

i agree that its not running on all cyl all the time. im thinking next time im gonna have it on near WOT and take a plug off and see what it does. i did that when i was at an idle. ill see how it sounds when its getting more rpms

 

[dbechtel71]

i want to get this running!!

 

[hardwater fisherman]

I put engine in a large tub and run it that way. I had the propeller off so water wouldn’t spray everywhere

Are you running full throttle without the prop?

 

[dbechtel71]

no not full throttle

 

[dbechtel71]

For the hell of it I took off thermostat housing and found no thermostat. Would that cause the problem? And of course I have water in my gear oil this after replacing all seals. Looks like the seal under the water impeller housing. Where can I find the best kit for seals?

 

[oldboat1]

Skip addition lower unit work until you figure out how to get the motor running. Return to it when ready to run. (You will need to at least pressure test to see if and where the l.u. is leaking.)

Buy a new fuel pump (cheap one is fine as mentioned above — square pump will bolt up). Borrow a known good tank and hose/bulb. Get some fresh 2-cycle oil if you don’t have it (TCW-3 rated), and fresh gas. Mix 5.5 oz. oil in each gallon of gas (24:1 ratio).

Put the prop on and test in a 32 gal trash can. Water level should be about half way up the leg of the motor, and a steady spray of water should come out of the port on the back of the leg. Keep the hose running, and don’t operate above a fast idle. Make sure the motor shifts into gear at a low idle without stalling. You really need a working thermostat to tune and run the motor.

You can come close to correct high speed mix in the test barrel without high revving. Try 3/4 open for initial setting.

 

[dbechtel71]

thank you oldboat1 i will try that