1968 Johnson 6hp CD25A engine dying

[hockeynut19]

I bought a 1968 Johnson engine. Ran ( took it for a drive on the lake) when we bought it but has been dying after running for a few minutes and will have a hard time restarting without choking. I found the fuel line( inside the engine) from the tank to the fuel pump leaking, replaced that, Replaced the spark plugs with NGK br6. Same problem. Spark plugs look good nice tan brown color. Any thoughts? TIA

 

[racerone]

I can not see or touch your engine.----So post the compression numbers here.----Does spark jump a gap of at least 1/4" on both leads.----Water pump impeller replaced ?

 

[hockeynut19]

I can not see or touch your engine.----So post the compression numbers here.----Does spark jump a gap of at least 1/4" on both leads.----Water pump impeller replaced ?

Thanks for your response. The water pump impeller has not been replaced. Engine is cool or barely warm after running for 5 mintues. I can keep it running by playing around with the choke and throttle. once running for a little bit it just dies. I will test the spark and getting a compression check on it and provide more info.

 

[hockeynut19]

Thanks for your response. The water pump impeller has not been replaced. Engine is cool or barely warm after running for 5 mintues. I can keep it running by playing around with the choke and throttle. once running for a little bit it just dies. I will test the spark and getting a compression check on it and provide more info.

The other thing from reading at Leeroysramblings it might be the condensers? After it cools down it will start again.

 

[racerone]

edited

 

[F_R]

The other thing from reading at Leeroysramblings it might be the condensers? After it cools down it will start again.

Classic symptoms of bad (cracked) coils. Have you checked them?

 

[hockeynut19]

I have not checked them. Just bought this boat and motor and few weeks ago ran fine a few times out then left us stranded, thank goodness we had the trolling motor!

 

[hockeynut19]

I have not checked them. Just bought this boat and motor and few weeks ago ran fine a few times out then left us stranded, thank goodness we had the trolling motor!

Here is what the coils and good stuff looks like. Looks like it’s been replaced.

 

[racerone]

Hard yo tell nut one set of points appears yo have more than a 0.020" gap.---Hurry to ----leroysramblings-----Best tutorial you can find to learn the simple stuff on this magneto.

 

[kbait]

Leroy/machinist‘s insights have been a godsend for me!

 

[airshot]

Thanks for your response. The water pump impeller has not been replaced. Engine is cool or barely warm after running for 5 mintues. I can keep it running by playing around with the choke and throttle. once running for a little bit it just dies. I will test the spark and getting a compression check on it and provide more info.

Playing with choke and throttle.....getting fuel??

 

[hockeynut19]

Playing with choke and throttle.....getting fuel??

seems to be getting fuel if i drop out the carb bowl screw fuel runs out.
I am going to replace the fuel pump with a OEM part. I did take the carb off and took out the slow speed idle adjustment screw noticed the packing was breaking down so replaced that with some string teflon I had laying around.
I will just rebuild the carb. Carb bowl was clean.

 

[airshot]

When you rebuild your carb get a rebuild kit, over my 50 plus years of boating, I have saw where just cleaning rarely works well, a thorough rebuild with new gaskets needle and seat is the proper way to go.

 

[hockeynut19]

When you rebuild your carb get a rebuild kit, over my 50 plus years of boating, I have saw where just cleaning rarely works well, a thorough rebuild with new gaskets needle and seat is the proper way to go.

That is what I did ordered a factory kit. Factory fuel pump. thx for your response.

 

[racerone]

A $7.00 diaphragm will fix those simple / reliable pumps every time.

 

[hockeynut19]

A $7.00 diaphragm will fix those simple / reliable pumps every time.

That is great to know!
Finally got it to purr like a kitten, set the points to .020” which were more like 0.030-0.035”, corrected the spark plug gap, cleaned/rebuilt the carb, replaced the primer bulb. The slow speed needle was set improperly. And the packing for that needle was trashed and pretty much gone. I am sure it was sucking air through the slow speed needle. Thanks for everyone’s advice!