#4 plug on 1986 Johnny 140 sooty

[talkinghead4]

The number 4 cylinder is sooty after about 35 hours on new plugs. I switched #3 and #4 coil to see if it was a weak coil but #4 still soots (is that a word?) up. The others are tan. Could the carb be a bit lean or is the VRO pump leaking some fuel in?

Oil side is disconnected - I premix.

Any suggestions appreciated.

Just wondering before I throw any money at it.

BTW This motor has Very low hours on it

Mark

 

[jonesg]

Re: #4 plug on 1986 Johnny 140 sooty

I think sooty means its running rich on that cyl, I'd look to the carb.
Sure the jets didn't get swapped by mistake ?

if it was the coil the plug would be wet.

 

[ezeke]

Re: #4 plug on 1986 Johnny 140 sooty

Test the VRO pump for a damaged membrane - #4 is the pulse piston for the pump.

 

[talkinghead4]

Re: #4 plug on 1986 Johnny 140 sooty

Thanks,
My carbs are clean and I did not pull or switch any of the jets when I cleaned out the carbs and I have no real engine running problems. Idles fine, on a plane in about 3 seconds. Good WOT. I think the fuel side of my VRO may be acting up and leak a little raw fuel into cylinder #4. I was suspicious of the VRO pump anyway. Very low hours, but that rubber membrane in the VRO does not last forever (23 years)!!!

Just to let you (ya'll' I'm in texas) this motor sat up more than it was run. I'll rebuild the VRO pump. I was kind of conserned about this anyway.

Thank You Iboats. forum/ the best on the net

Thank You
Mark.

 

[kenmyfam]

Re: #4 plug on 1986 Johnny 140 sooty

Rebuild or replace. Only the fuel side is re-buildable.

 

[talkinghead4]

Re: #4 plug on 1986 Johnny 140 sooty

Thank You,

I'll do that.


kenmyfam We have the same outboard. Darn good machines aren't they!
Someday I'll have more knowledge so i CAN CONTRIBUTE!

Thank You'
Mark

 

[talkinghead4]

Re: #4 plug on 1986 Johnny 140 sooty

ezeke'
jonesg
Thank You for the reply.
Life is great on water@!!!!

 

[kenmyfam]

Re: #4 plug on 1986 Johnny 140 sooty

Thank You,

I'll do that.


kenmyfam We have the same outboard. Darn good machines aren't they!
Someday I'll have more knowledge so i CAN CONTRIBUTE!

Thank You'
Mark

They are a great motor. Dependable with minimum maintenance. As far as contributing, you just did.