starter barely turns engine over 79 Johnson 100hp

[ssutter76]

I have a 79 Johnson Javelin 100 hp 4 cylinder that with a starting issue. Despite fresh batteries and a jump box, the starter does not have the power to turn the engine over fast enough to start. I have verified fuel delivery and spark. The starter freely turns the engine over with the spark plugs removed. With the plugs in, the battery connection gets hot. I suspect an exhaust back pressure issue but am not sure. Ideas?

 

[Calpastor]

Re: starter barely turns engine over 79 Johnson 100hp

I have a 79 Johnson Javelin 100 hp 4 cylinder that with a starting issue. Despite fresh batteries and a jump box, the starter does not have the power to turn the engine over fast enough to start. I have verified fuel delivery and spark. The starter freely turns the engine over with the spark plugs removed. With the plugs in, the battery connection gets hot. I suspect an exhaust back pressure issue but am not sure. Ideas?

I'm having the same problem with a 69 Johnson 85 hp, I have ordered a new starter.

 

[ssutter76]

Re: starter barely turns engine over 79 Johnson 100hp

I have a 79 Johnson Javelin 100 hp 4 cylinder that with a starting issue. Despite fresh batteries and a jump box, the starter does not have the power to turn the engine over fast enough to start. I have verified fuel delivery and spark. The starter freely turns the engine over with the spark plugs removed. With the plugs in, the battery connection gets hot. I suspect an exhaust back pressure issue but am not sure. Ideas?

I'm having the same problem with a 69 Johnson 85 hp, I have ordered a new starter.

 

[Barnacle_Bill]

Re: starter barely turns engine over 79 Johnson 100hp

Your starter probably needs to be rebuilt. But check all your connections to be sure they are clean and tight. Look for signs of corrosion at the base of the lugs. They can corrode inside where you can't see it. It cost me $130 to learn that lesson.

 

[jtexas]

Re: starter barely turns engine over 79 Johnson 100hp

Those starters are pretty easy to rebuild - cost me $50 for a brush set - prestolite, out of production - if you have the American Bosch starter might be more economical.

But yes do check connections & cables first.

Directions are in the manual - seloc and OEM.

 

[dsinger]

Re: starter barely turns engine over 79 Johnson 100hp

Brush Set for $14.00 american. Check with your local automotive electircal shops. Just take what is left of the brush set with ya and the brush holder. And you will need some rubber bands or wire ties.

 

[emdsapmgr]

Re: starter barely turns engine over 79 Johnson 100hp

Make sure that your timer base is moving correctly. Specifically, that it is going back to idle timing when in neutral. If the base is advanced, you will get the high compression, hard starting you mentioned.

 

[ssutter76]

Re: starter barely turns engine over 79 Johnson 100hp

Thanks for the suggestions. I am in the process of rewiring the entire boat (79 Hyrdostream Viper that has been significantly altered electronically) and have also ordered a new starter (the gear interfacing with the flywheel was significantly worn and I could not find that part individually). I'm curious as to how to verify that the timer base is moving correctly - when the motor was running it seemed to alternate between idle and in-gear speeds normally; however I do not know how to verify this when it is not running.

 

[funpilot]

Re: starter barely turns engine over 79 Johnson 100hp

You can visually inspect the timing base to make sure that it is moving with the throttle, that won't tell you if it is right, but it will tell you if the linkage is stuck. If timing is too advanced at idle, the ignition of the spark will not allow the starter to overcome the powerstroke as it tries to turn the engine over. That's why early cars had manual spark advance on the column so you could turn the engine over with the crank, and then advance the spark once the engine started. I've seen four cylinder car engines with their timing so advanced that the starter wouldn't turn them over until timing is properly set.

You can put a timing light on it once you get it started. You will be able to see the idle timing (low, somewhere around four to six BTDC I would imagine) and see it increasing at higher idle speeds. A manual should tell you how to check your timing. It's important to get it right.

fp

 

[ssutter76]

Re: starter barely turns engine over 79 Johnson 100hp

You can visually inspect the timing base to make sure that it is moving with the throttle, that won't tell you if it is right, but it will tell you if the linkage is stuck. If timing is too advanced at idle, the ignition of the spark will not allow the starter to overcome the powerstroke as it tries to turn the engine over. That's why early cars had manual spark advance on the column so you could turn the engine over with the crank, and then advance the spark once the engine started. I've seen four cylinder car engines with their timing so advanced that the starter wouldn't turn them over until timing is properly set.

You can put a timing light on it once you get it started. You will be able to see the idle timing (low, somewhere around four to six BTDC I would imagine) and see it increasing at higher idle speeds. A manual should tell you how to check your timing. It's important to get it right.

fp

 

[F_R]

Re: starter barely turns engine over 79 Johnson 100hp

You say the battery connection gets hot. That should be a clue. Heat is caused by resistance. Check the connection and cable. Also, very high amperage may heat up the entire cable, but that's a different story.

 

[ssutter76]

Re: starter barely turns engine over 79 Johnson 100hp

Thanks for the info - the timing base seemed to be in proper alignment and therefore, I went ahead and installed my replacement starter. FYI - This was purchased off of Ebay for 126.00 and proved to be quite the installation challenge. The mount locations appeared to be correct on inspection; however I found them to be quite a bit off once installed. This required bending the starter mounting brackets considerably to match up with the flywheel. I don't know if this is a common occurrence in boat engines; however I was regretting not ordering the OEM part half way through the installation. Regardless, the issue is resolved and I'm back on the water. Thanks for the information!

 

[AlanR]

Re: starter barely turns engine over 79 Johnson 100hp

Yeh id say cruddy conection or the burshes in your starter