ignition/fuel delivery question 1999 Johnson J90 PLEEB

[Tex Aggie]

i have gone through all 4 carbs. When I crank motor at idle or high idle, the motor seems to be missing/sputtering/spitting. I have tried moving spark plugs, wires, etc...

On the muffs, I revved the motor up good and got her opened up a bit. This motor had been sitting for several years. I've been thinking that it needed to be ran and gotten warm to "clean her out some." so to speak. At fast speed, the motor smoothed out and wasn't missing anymore. Then when I was throttling back down, it didn't want to immediately drop RPMs and come back to idle right away. Then after a few seconds it idled back down and ran smooth.

I let it sit a few minutes and cranked it again on the muffs. Same issue. It wasn't running right at idle or high idle. It likes to sputter trying to get up to speed, then smoothes out when it is running fast.

After this i took the spark plugs out of all 4 cylinders. The starboard side top and bottom plugs are wet, while the port side appear dry and normal.

Is this a fuel delivery issue with the carbs? a needle valve not set properly? what am i looking at here?

thanks for any help!

 

[Haffiman]

Re: ignition/fuel delivery question 1999 Johnson J90 PLEEB

If you want to kill the engine, keep reving it on the muffs! If you are real lucky, you end up with a 'run-away' that will self disintegrate in your yard!!!
Running on muffs is idle only!!
Test it in water under load, or hook it to a dyno and get some load on it.

 

[Chris1956]

Re: ignition/fuel delivery question 1999 Johnson J90 PLEEB

Sounds like the carbs are still an issue. Did you clean and rebuild them with new gaskets, floats and inlet needles and seats? Did you adjust the idle mixture.