Please help Johnson 15 HP

[ajohnson035]

I have a 94 johnson 15hp I have been working on seems to have a fuel problem. The carb has been rebuilt with no success it has new plugs in it as well. I have taken this motor to the shop twice and they have not been able to fix it. It takes 6-8 pulls to start the motor and it only runs for about 8 seconds then cuts off it will not idle what so ever and it also will not restart after it cuts off. I pulled the plugs out and they are wet the float is not sticking on the carb and the only adjustment on it is the idle screw so I don't know what else to do as the carb has been rebuilt with all new gaskets needle and seat as well. I thought at first it may be starving for fuel but it seems to be flooding out. Please help because the mechanics have been no luck twice just took my money and left me with the still headache. Thanks for your time and effort.

 

[JB]

Re: Please help Johnson 15 HP

Check the fuel pump and fuel supply. It is burning up the fuel in the carb, which is not getting any more fuel.

 

[clanton]

Re: Please help Johnson 15 HP

Go to brpparts look at diagram for carb, If part # 30 plug is not installed correctly, crab could run rich or lean. Sometimes the carb body will corrode in same area of plug, the plug will not seal. If plug is driven too deep into the carb body engine runs rich. Some aftermarket carb kits donot always have these plugs and seals.

 

[Rick.]

Re: Please help Johnson 15 HP

Hello there. Sorry to hear about your problem. In the "engine faq" part of this forum you will find a whole lot of information that may help with your problem. It sure sounds like fuel to me. Pay special attention to the needle adjustment by Joe Reeves. That could be all you have to fix. There is the link and sync as well and just a wealth of good information. Have a read and try to accomplish some of the checks mentioned. Let us know if you gain any ground. You will certainly gain some knowledge either way. Best of luck. Rick.

 

[Vic.S]

Re: Please help Johnson 15 HP

People often cannot find the engine FAQs (They click FAQ in the blue banner above and learn about how to use the forum instead!)

Engine FAQs are HERE

Lot of info on 15hp engines in an item near the bottom of the first page. Joe Reeves instructions on carb needles immediately above.

 

[mikesea]

Re: Please help Johnson 15 HP

you may have a broken diaphram in the fuel pump which is allowing fuel to pass thru the pulse and flooding the engine,remove the fuel pump leave hooked to the fuel line,squeeze the ball,if gas comes outwhere the pulse hole is on back its the fuel pump,