1985 Johnson 50Hp HELPPPPP!!!!!

[jeffro9]

Hello all New to the site and love it already!!

I am posting this for my grandfather he is having problems with his motor.
all started last season .. would start fine and idle fine and troll but once opend up it would pick up speed then sputter and die right down to a low speed almost like its under load. would prime the bulb and it seemed to surge and pick up again. Figure this was either carb or fuel pump problems. So carbs have been cleaned and rebuilt . Linage all adjusted, And apparently the fuel pump is fine acoording to the marine mechanic who has been working on it. have took it out to the lake 3 times to test after he has fooled around with it and same problem.

seems to run fine at the dock .. get up to speed then boom .. cuts in and out and die right down.

Any suggestes ?????


here is a video of how it sounds after its been up to speed and dies off

http://www.youtube.com/watch?v=um11C_QxRgQ

after this we could not get it to idle down low enough to get it into gear so we had to use the kicker to get back in!

Any suggestions Comments welcom

thanks in advance!!!!!!

 

[fireman57]

Re: 1985 Johnson 50Hp HELPPPPP!!!!!

Welcome to iboats. Sorry no one has tried to diagnose your problem yet. It sounds to me like a stuck float. I know that you had a mechanic working on it but the new needles have a coating on them that makes them prone to sticking. You are probably running on one cylinder when you are trolling because they will start and sound like they are running right on one cylinder. You may not be getting gas to the other cylinder. It is easy to check. Put the engine in a trash can full of water, I hate muffs, and pull the spark plugs and watch for a mist to come out of both cylinders. If it only comes out of one then pull that carb and check the needle valve under the float. If you have mist from both cylinders then you have to check spark. Make sure that you have good blue spark on both cylinders. when you pump the primer bulb and it picks up that is the test for a bad fuel pump. Disconnect the fuel line going to the engine and crank it over and make sure that it pulses fuel.

 

[jeffro9]

Re: 1985 Johnson 50Hp HELPPPPP!!!!!

Hmmm makes sense to me! I seemed to think it was only running on one cylinder to but i was unsure. so to check that you would put the muff or can of water to it and start it and pull one plug at a time and make sure its spraying fuel if not then check that carb that feeds that cyl.

 

[fireman57]

Re: 1985 Johnson 50Hp HELPPPPP!!!!!

pull both plugs before you start it and look for mist when you crank it.