1/4 speed at wot

[larryg]

i have a 1985 joh 20.j20crcos.i have replaced both coils,powerpak,plugs,plug wires,all new fuellines on motor n to motor.it runs great then all of a sudden it loses power and runs like a 10 horse.it will pik bak up after a while.today it ran great then did the same thing then never picked back up.it starts right back up after i shut it down.and it still has spark,tested it with tester when i gt home.

 

[Monte1961]

Re: 1/4 speed at wot

When was the last time the carb/s were overhauled? If yer thinking that its coils breaking down when hot, that needs to be done when issue is happening, otherwise you could get false readings.

 

[larryg]

Re: 1/4 speed at wot

rebuilt 5 days ago and tore apart yesterday before i went out today.i have no clue what it could be,if it were the coils there would be a problem starting?it fires right up.

 

[Daviet]

Re: 1/4 speed at wot

Use an inductive timing light to check spark when the problem happens. If you have good spark, you still have a fuel problem. When you overhauled the carb did you remove the high speed orifice and make sure it was clean?

 

[Monte1961]

Re: 1/4 speed at wot

Coils can be tricky, When they get hot, they can try and short themselves out. When cold they work fine. If you can get your hands on some known good ones to see if it cures issue, I would do so! Good luck sir!

 

[Randy J]

Re: 1/4 speed at wot

good ol outboard did ya check for fuel tank vent to be open or closed ?? i forgot that a few times in old days lolo

 

[larryg]

Re: 1/4 speed at wot

yes i leave it open all the time.yes the carb was complete ripped apart.here is a pic of the plugs.one on right is from lower cylinder.

 

[Daviet]

Re: 1/4 speed at wot

The plug on the right looks pretty fouled, install it in the upper cylinder and see if the moves to the top cylinder.

 

[larryg]

Re: 1/4 speed at wot

i was initially having problems with the motor restarting.took it to some backyard mechanics.they got it running,bt i didnt hv full throttle,n it was hard to start out in water.i fixed throttle and turned low idle out abt 2 turns,starts right up,when i pull start it n it fires ,it has a slight bak fire for a few seconds then straightens out.should i just turn it back in??

 

[Daviet]

Re: 1/4 speed at wot

If it is backfiring at an idle it is usually called a lean sneeze, turn the low speed jet OUT about a 1/8 to 1/4 turn and see if ti helps.

 

[larryg]

Re: 1/4 speed at wot

it is turned almost 2 turns out already.couldnt get it sounding good at 1 1/4 out within that area.the motor had seafoam put in it abt 3 tankfulls ago.1 can to 6gal.i go out 1or twice a week.

 

[nrf414]

Re: 1/4 speed at wot

Did you replace those plugs after you ran the seafoam through? The plug in the right looks pretty nasty. I would be suprised it ran that good just judging from the plugs.