johnson with no power lol

[drewandamy224]

I have a 78 140 johnson and the boat is new to me sat for 2 years. when i go out on the water it will jump up and plain and then i lose power.i have changed plugs,new fuel lines filter and hand pump.cleaned out the carbs with carb cleaner but no change.could it be the coil? please help first boat for me and i'm sinking with the family fast.

 

[Chris1956]

Re: johnson with no power lol

Drew, Have a helper pump the primer bulb, when it starts to die out. If the motor speeds up, you likely have a fuel delivery problem, usually caused by a weak fuel pump or bad venting on the gas tank. If the primer bulb collapses, it is very likely a bad (plugged) vent on the gas tank. If it turns out the fuel pump is weak, you can easily(and cheaply) rebuild it.

 

[fireman57]

Re: johnson with no power lol

Sounds like it's time to disassemble and rebuild your carbs. You probably have gunk in at least one of the high speed jets. Before you do this (even though in my opinion it should be done) check for spark when you lose power with a timing light and a friend. report your findings and Welcom to iboats!

 

[Chum Slick]

Re: johnson with no power lol

Did you just spray cleaner in the carbs or remove them and give them a good cleaning? You can't really clean them by spraying cleaner in them.

 

[drewandamy224]

Re: johnson with no power lol

I just sprayed them down with cleaner. will pull them tonight and do it right. and my hand pump just colapses it wont hold presure at all.

 

[drewandamy224]

Re: johnson with no power lol

now with the muffs on at home i get rael good power but under a load it just dies out

 

[fishnfiend]

Re: johnson with no power lol

The primer bulb needs to get firm and stay firm before you start the engine. When running, as the fuel pump draws fuel, the bulb is about half full (not firm when running.) If the bulb won't get firm when engine is off, check for fuel leaking externally. If no external leaks, you probably have a hole in the fuel pump diaphragm as Chris posted. Rebuilding the carbs (clean out ALL passages with syringe/alcohol or a fine wire) is a good idea after sitting too long. Don't run engine too much with junk in carbs - lean condition can scorch a cylinder.

 

[rwise]

Re: johnson with no power lol

Originally posted by drewandamy224:<br /> and my hand pump just colapses it wont hold presure at all.

just a thought here, try removing the gas cap (at least lose) and run it, if this lets it run you have a vent that is closed or pluged.

 

[drewandamy224]

Re: johnson with no power lol

thanks everyone will check all tonight