40 HP idles rough

[Curby]

Hello,<br />New to forum. Great info here. <br />Problem: 2002 40 HP Merc 2 cyl 2 cycle Low hours.<br />Idles rough, when I throttle up it bogs down and quits! I have new tank of gas (90+ oct).First noticed problem at end of last summer when it showed signs of rough idle and slowing down at top end. I pulled the plugs and both were fouled. Cleaned them up and tried again and plugs fouled again. Engine has oil injection system. Any help is greatly appreciated.

 

[bluegillspeed]

Re: 40 HP idles rough

Sounds like the oil injection has started dumping to much oil into the engine. I havn't worked with oil injection much but you could try disconnecting the oil injection system and putting oil into the gas manually. If that solves the problem you can run it like that just fine but I would look into fixing the oil injection system as soon as possible, if you not used to adding oil manually its easy to forget and that would ruin the powerhead. you oil ratio is propably 50:1 or 1 pint to 6 gals.

 

[Elmer Fudge]

Re: 40 HP idles rough

It looks like you're running too rich, but before leaning it out check the t/stat and make sure that it is not stuck open,that can also cause the plugs to foul.