Rough idle and wet fouling the plug

[Big Daddy J]

Hey folks if you could help me, I have a 1995 20 hp evinrude and it's loading up on fuel and wet fouling the plugs. Fire is good and so is the carb. What's the problem you ask; it's idling rough and wants to stall at slow idle. Once it warms up it seems to run fine but if I shut it off after it's warmed then start it again it does the same thing.???? what dod I fix?

 

[Dhadley]

Re: Rough idle and wet fouling the plug

Welcome!!<br /><br />Lets get some basics. What spark plugs are you using? Are the thermostats in and working properly?<br /><br />All the grounds and connections clean on the coils? How old is the fuel? What oil? What ratio mix?

 

[MCM]

Re: Rough idle and wet fouling the plug

Welcome Big Daddy J, <br /><br />Just to add to Dhadleys advice and questions, you say the fire is good. Having spark and having the proper spark is not exactly the same thing, is the spark strong, blue and snappy or weak and yellow in color? how far will the spark jump? You say the carb is good, was it cleaned/rebuilt recently?

 

[Big Daddy J]

Re: Rough idle and wet fouling the plug

Thanks for the imput the spark is good and the plugs are new the are ngk perma gaps(the right ones). the carb has just been dunked and had a new kit in it. Grounds all seem good. The machine takes right off (starts great). It seems more like improper fuel delivery. Fuel is mixed right and the gas is new high grade gas. Is there some way to check the fuel pump.

 

[Big Daddy J]

Re: Rough idle and wet fouling the plug

One other thing the spark plugs that were in it were champion but they were fouling as well. There also seems to be a lot of exhaust. More than normal, it's blue grey.

 

[Dhadley]

Re: Rough idle and wet fouling the plug

OK, good info. Lets start with getting the right plugs in there. Champions only in an Evin/John. I'd suggest the QL77JC4's. Then lets get the correct fuel. That motor is designed to run on 87 octane. Just make sure it's fresh. <br /><br />How about the thermostats? Are they in there?

 

[Big Daddy J]

Re: Rough idle and wet fouling the plug

The outboard did have good L77JC4's in it but it was still doing the same thing, champ or ngk either made no difference.

 

[Dhadley]

Re: Rough idle and wet fouling the plug

Switching back to Champs may not solve the current problem but we need to get back to square 1. The Evin/John motors are designed around the Champion plug. Another brand plug may or may not have the same burn characteristics which may create other problems / symptoms. We also dont want to risk a burned piston. Especially with high test fuel.<br /><br />How about the thermostat? Is it in the motor and working properly?

 

[Big Daddy J]

Re: Rough idle and wet fouling the plug

Thanks for the info i'll have to get back to you about the thermostat after the holidays.

 

[Dhadley]

Re: Rough idle and wet fouling the plug

Cool (so to speak)! Have a great and safe holiday!