1990 Mercrury V6 Fouls Plugs Help

[kgraham]

I have a 1990 Black Max Mercury that I am having problems with. It will run good for 6 or 7 trips then foul the plugs. When I put a new set of plugs in, it runs good, until the next time it fouls them. Now it seems like it's not quite running on all cylinders also. If anyone has any ideas I would appreciate it. I've already sunk a lot of money in this. The compression is good, stator is good, they want to put a new idle stabilizer in and if that's not it then they will go after the carbuerators. This could get very expensive. Help!

 

[Pursuit2150]

Re: 1990 Mercrury V6 Fouls Plugs Help

When you pull the plugs are they black and covered with oil?

 

[kgraham]

Re: 1990 Mercrury V6 Fouls Plugs Help

Yes they are black and wet.

 

[clanton]

Re: 1990 Mercrury V6 Fouls Plugs Help

There is specs in service manual to trouble shoot idle stabilizer, without swaping parts just to see if that was the problem, my book starts at 1992 and refs service bulletin 91-35. Did they check stator with peak reading meter and engine running?

 

[kgraham]

Re: 1990 Mercrury V6 Fouls Plugs Help

Yes, they check the stabilizer that way. To be honest, they don't know what is wrong. They know the stabilzer needs replacing and we are hoping that will fix the problem. If not, then they go for the carbs at $65 an hour for each carb. Their troubleshooting is going to cost me a lot of money, but I'm not a mechanic. Last summer I took it in and a Mercury dealer put in a new diaphragm kit and valve-check. They did several other checks and everthing was ok. I got the boat back and it started up and purred great, best it ever ran since I had it. I ran it 5 or 6 times and it fouled the plugs again. I put new plugs in and it started and ran fine, until the next time it fouled. Now it misses a little while it's running and is real smoky. Any ideas would be greatly appreciated. Thanks.

 

[Pursuit2150]

Re: 1990 Mercrury V6 Fouls Plugs Help

It's beginning to sound like too much oil!