1973 Johnson 65 Runs great until warm and then does not want to restart

[fishingwithdad]

Hi, I have searched everywhere here and I have found all kinds of info that has been very usfull. Thanks to everyone. Unfortunatly I have not come accross the issue I am having. It is possible I just missed it. I have a 1973 Johnson 65HP, MDL#6573L-ESR. It ran great all last year and now this year I am having problems. I put a new impeller in it and had to reseal the exhoust/water jackets which required removeing the power head. It start and runs fine every time, especially in the driveway. But when She hits the water and rus for a while and the is shut down while hitting that favorit fishing hole She does not want to restart, just cranks over and over untill I remove the cover and mess with the linckages to the throttle and timing advance. Get it home and I cant duplicate it. Fires every time no matter what I do unless I put it in gear or push the timing advance all the way forward and then it will not turn over at all. Seems to only be when She is warm. Any Help would be great.
Thanks, David

 

[jonesg]

Re: 1973 Johnson 65 Runs great until warm and then does not want to restart

running it on the hose at home gets it warm so its not that, maybe its when it gets hot hot.

When it quits, do you have spark?

The time to diagnose is when it will not start, unfortunately what you're doing gets it going but doesn't tell you anything.

It could be heat soak, then you remove the hood to fiddle with it and it actually cools down, what you do with the linkage might have nothing to do with it. Take a timing light with you or spark gap tester and do some troubleshooting next time. Otherwise we can all guess but its just guesses.
You might try a little spray bottle with premix fuel in it, in case its not getting cold fuel, spray into the carb throat.

 

[fishingwithdad]

Re: 1973 Johnson 65 Runs great until warm and then does not want to restart

running it on the hose at home gets it warm so its not that, maybe its when it gets hot hot.

When it quits, do you have spark?

The time to diagnose is when it will not start, unfortunately what you're doing gets it going but doesn't tell you anything.

It could be heat soak, then you remove the hood to fiddle with it and it actually cools down, what you do with the linkage might have nothing to do with it. Take a timing light with you or spark gap tester and do some troubleshooting next time. Otherwise we can all guess but its just guesses.
You might try a little spray bottle with premix fuel in it, in case its not getting cold fuel, spray into the carb throat.

Yes, you are right. Not much info and guessing is never a great idea. Talked with my fishing friends and we have decided to take the boats out with some tools and a timing light, etc,etc and diag it right on the water while it is happening. I read about heat soak and it may be that. It all started one day when I went to put it in the water and the motor would not start at all. Had no spark what so ever. (Suspected the power pack) Put it in the water and fished with the troler and later tried the motor and it fired right up and every since it has always fired right up cold and ran great until warm and then not restarted (power pack?). I also failed to mention this last time after launching the boat the motor fired right up and idled slowly past the wake zone when giving it full throttle it would not accelerate. Did this this for about 45 to 60 seconds and then suddenly came alive. I am suspecting the power pack again at this point but as I said you are right I will get out their and do the proper diag and let you know.
Thanks