engine running wierd

[Jigsaw404]

Hi,

I have a 1976 4hp Johnson seahorse, I am at a lost. The engine starts but only runs on one spark. I know this because on very rare occasions I let it idle and play with the lean and rich settings...then the second spark starts to work and the engine runs great. They are new plugs. I tested 2 new packs of plugs to test..and still the same problem. I dont know what to check from here on out, I have a great supply of fuel, compression is good. The only thing left is to check the electrical. So, I have cranked it a few time with the spark plugs attached and grounded and both light up very noticably... so again I dont get it. I'm almost ready to give up and bring it in, but I pretty sure its something easy to fix. Has anyone had this sort of a problem?

 

[JB]

Re: engine running wierd

Howdy, jigsaw.

Welcome to iboats.

You have one of the best outboards ever made, by anyone.

She deserves the best care. She will then give another 40-50 years of great service.

You may have 2 problems. Playing with the mixture should not affect any change in spark, but it might allow a cylinder to fire temporarily on a poor spark.

At her age your outboard deserves new coils. They need to make good spark in the cylinder under pressure.

You will do yourself a big favor and probably save a lot of bux over time if you get the factory Service Manual. www.outboardbooks.com.

Good luck, and let us know how you do.

 

[Jigsaw404]

Re: Engine running weird

Re: Engine running weird

Thanks JB,

The engine was giving to me since the guy who had it didnt want nothing to do with it. It was not starting(I put a carb kit), the main seals in the foot were leaking(replaced those). Under the cowl, it's immaculate just like it was bought yesterday. So, I jumped on it, I needed an outboard for my 12foot aluminum. I'm sure glad I did decide to invest a little money, being light weight and simple mechanics I know when it will be working fine, it will last me for good.

So, I took off the flywheel... and sure enough the coils were in a million pieces. At the touch of my fingers the casing that surrounds the coil was falling off. I cleaned up all the mess... One of the coils had a hole in it and was shorting on the base plate(where everything is attached).

Last question, is there anything else I should replace while I have the flywheel off. The points look mint, and the condensors seem to be in great shape. Whats your input?

 

[CATransplant]

Re: engine running wierd

If the points and condensers look fine, I'd just keep them and replace just the coils. But, that's just me. It doesn't cost that much for new ones, and lots of guys would replace everything, just for good measure.

Do torque the flywheel down to the proper torque setting. I don't know what that is for your 4 hp.

Once you're done, you should have a very reliable little outboard for your 12' boat.