Spark plug carbing up at trolling speed

[todgil]

When i'm trolling with my 1979 5 hp suzuki twin it starts to carbon up just on one cylinder after about 1/2 hour to 45 minutes.<br />More often then not I have to remove the plug and scrap the carbon fron the plug.<br />I'm using BPR6HS NGK plugs.<br />Is their anything I can do to prevent this?<br />Thanks.

 

[jim dozier]

Re: Spark plug carbing up at trolling speed

If this is an auxilliary motor you may want to look into getting a prop with less pitch that will allow the engine to run at a higher rpm. It may just be that you are lugging the engine, which will shorten its life. Will this engine reach its recommended max rpm under full throttle? If not you are over propped. If the prop turns out to be OK and the engine runs well otherwise, try going to a hotter plug.