Spark Plug Fouling

58Whaler

Cadet
Joined
Jan 17, 2003
Messages
15
I have a yammy 80 four stroker. I ran it at idle for about 30mins the other day. It ran fine but I was wondering if my plugs would be fouled. If not how long does it take for them to get fouled from running at low speeds?
 

dmessy

Chief Petty Officer
Joined
Jul 8, 2001
Messages
505
Re: Spark Plug Fouling

Your plugs wouldn't oil foul which is the most common type as you have a 4 stroke. You should be able to troll(or run at idle) for a very long time without any problems. You may have blown a peice of carbon off, bridging the center/side electrode gap causing a misfire but this too could be eleminated if you are running(or can get) permagap type plugs( no side electrode). Pull your plugs and do a read, should be dark tan colored. Black would indicate a too rich of a situation, so an idle mixture or slide needle (if equipted) adjustment would be in order.
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Spark Plug Fouling

I run a Honda 15 hp 4stroke for a kicker while fishing at 1.5-3 MPH w/ my 23' Seacraft and run 5-6 hours at a time @ slow speed and never have trouble w/ fouling. Your could not do that w/ 2 strokes w/o reeving up once in awhile. I have ran a 9.9 Evenrude & a 9.9 Johnson and that was what I had to do to keep them idling for long periods. Just my $.02
 
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