60 HP Johnson 1970 starting issue

[navytech79]

I have a problem when starting the above outboard motor. I was able to start the engine about a week ago with relative ease. I tried to start it yesterday and it would crank, rev up really high and then die. I only used the choke on the initial start, and after that did not use it. Also, when I was able to start it last weekend, I took it out and noticed that the engine started to die when I was almost at full speed. I changed out the fuel, but still no joy. Please help.

 

[CharlieB]

Re: 60 HP Johnson 1970 starting issue

Is this motor new to you or is this a new problem?

Additional fuel from a choke or enrichener will cause RPM to jump until the majority of the additional fuel is burned off. If the engine is still too cold it may die without another quick touch of the choke /enrichener again for just a heartbeat. Retouch as required until the engine warms enough to idle at a moderate speed that you can control with the fast idle lever.

When operating the craft at or near WOT and the engine does not seem to perform well, first pump the primer bulb, if performance pick up again then you can be pretty sure there is a restriction in the fuel supply, a weak fuel pump, air leak into a line, restricted hose, fitting, or vent. IMMEDIATELY REDUCE THROTTLE as continued operation at WOT with a restricted fuel supply WILL CAUSE DAMAGE due to leaning mixtures elevated burning temps.

 

[navytech79]

Re: 60 HP Johnson 1970 starting issue

This motor is new to me. I have only had the boat long enough to take it out once, and I did not have a starting issue like this. But the person I bought the boat from did warn me that sometimes it was hard to start. Thanks for you help. It is much appreciated.

 

[navytech79]

Re: 60 HP Johnson 1970 starting issue

I tried to start her up yesterday and it would not turn over. I decided to check the spark plugs. They looked clean (relatively new) but I am not sure what the gap should be. When I re-installed the spark plugs and tried to start her up again, it did turn over this time, but the engine revved up high again and then shut off. I tried to crank it again after this and it would not turn over. So I removed the spark plug again and re-installed it and she started up and did the high rev thing and shut off once again. Is this an air mixture issue? Please help me.

 

[navytech79]

Re: 60 HP Johnson 1970 starting issue

The spark plug gaps look good, and they are firing. Checked the fuel flow to through all the hoses and they are good, but did notice that the bottom 2 carbs are not getting fuel, so I think maybe the float is damaged. Will check that today or tomorrow.

 

[navytech79]

Re: 60 HP Johnson 1970 starting issue

The floater pin was getting stuck and blocking any fuel flow to the carb. Cleaned them out and engine started right up. It is still idling extremely hard and dies out a few times until the motor is warmed up. Also noticed that the engine dies when switching to F or R and not accelerating quickly. Any ideas would be appreciated.