2003 125 outboard idle rough

[boater pat]

I know about the no idle circut in 2 carbs. Every time i come off plane runs rough. I noticed the top 2 carbs have idle adjustment screws with springs while the bottom 2 have screws with no springs turned all the way in. Any advice to fix this problem would be helpful.

 

[MarineTechStudent]

Re: 2003 125 outboard idle rough

is the only time that you have the condition when you come off plane?

 

[imported_JD__]

Re: 2003 125 outboard idle rough

boaterpat,<br />What you are experiencing is a transition from running on four carbs/cylinders back to two. First; when you come off plane, don't just shut the engine down to an idle. Keep the engine just under 1800 rpm's for a few seconds.(or below whatever rpm the two other carbs kick in). This will burn up all the remaining fuel in cylinders 3&4. When you come off plane, idling or trolling around, keep the cowl/engine as level as possible. <br />JD

 

[Elmer Fudge]

Re: 2003 125 outboard idle rough

Hi Boater Pat, try cleaning those carbs and change your plugs,inspection of the old plugs will tell you if you're running too rich/lean.Keep posting and let us know how you progress

 

[Hooty]

Re: 2003 125 outboard idle rough

^<br /><br />c/6<br />Hooty

 

[Mercury140-I6]

Re: 2003 125 outboard idle rough

Another option is to buy 2 more of the carbs that have the idle circuit and replace the 2 that don't. That way it will run on all 4 all the time.<br /><br />It's an option.<br /><br />Craig

 

[dilligafda]

Re: 2003 125 outboard idle rough

If it's a 2003, is it in warranty?

 

[WillyBWright]

Re: 2003 125 outboard idle rough

Forget the changing the carbs idea. Sorry. They did that because the prototypes ran like pure crap on all four cylinders. Then they had to enlarge the holes in the throttle plates to get the right RPMs while idling on just two carbs. Put 2 more of the same carbs on and it'll idle way too high and there's nothing you'd be able to do about it without really screwing-up the timing. This motor has a lot of issues that you just plain have to put-up with. Look for this motor to be discontinued altogether in the very near future. They sure run-out nicely, though. Just these nasty few quirks that drive a lot of people up walls.

 

[SingleShot]

Re: 2003 125 outboard idle rough

I have the same motor, I assume your done breaking in. Mine ran like crap until I finaly weened it off the pre mix in the tank. Runs great, but like JD pointed out, when you come off plane run it just below the breaking point and you will be fine. I needed to do this any ways to keep the wake from rolling over the transom. Once I found the sweet spot on the throttle it runs like any other motor. Idles great for running on only two cylinders.<br /><br />SingleShot

 

[boater pat]

Re: 2003 125 outboard idle rough

Thank you all for the great responces. I think i have found somthimg that works well. As long as i keep the engine at idle in the trimmed out postion for a couple of minutes it idles good. Thanks agian!