Alittle help please !

[Superchamp05]

I have a 2004 ox66 225 and just noticed a slightly rough idle, when I crack the throttle to get on plane it is fine ! Recently I have found a fishing spot that doesn't require me to run at all ! Alot of 6 mph ! What should I do or look at first ? Thanks !!!!

[falcooon]

No expert but...

I would check that the plugs are clean and the o2 sensor. This issue may be difficult to solve as being in gear and at idle can be tricky to iron out small roughness in operation. Air, fuel, and oil ratios are not very predictable in these low rpm areas...

[Rich Z]

Yep…plugs, check for excessive coloration and if they haven’t been replaced in a while I would go ahead and install new ones. How old is your cranking battery? A degraded batter even though it’s freshly charged can put a drain on your charging system and motor will run rich. Lastly, if the injectors haven’t been serviced in this motor then it’s about time. We find flooding injectors on these motors every single day and sometimes cleaning is not enough. They may need to be calibrated back to spec. Call Brucato for injector service. They are the best.

[Superchamp05]

Thanks guys ! Plugs are new every season, cranking battery is brand new ! May check the 02 sensor clean it then take it from there ! This just started a week ago ! Hopfully I'll get to the bottom of it !

[Rich Z]

I’m positive that the Potomac season starts in Mar and if you installed your plugs in Mar, I don’t think they are new anymore…just sayin

[Superchamp05]

Got the 02 out and boy what a mess ! Been 7 yrs never taken out ! got it soaking in some seafoam ! Also took the 02 mount off and have to take it to work to clean this thing out very clogged ! Boy I need to stay on top of this crap but it something that I didn't know about ! Will keep you guys posted thanks !

[Lunkerlure]

I have twin 250 ox66's and I clean the o2 sensors every year. Seafoam works great but last time I used the Evinrude brand of decarb spray and I think it worked better. Did you also pull out the little tube that runs between the sensor and block?

[TX187Champ]

Ive noticed mine doing this as well but I have a vmax 150 carbed version , but It only dosent after say I fish a spot and crank up to leave itl idle real low and almost die in gear but in nuetral its fine. But if I go ahead and hit it itl jump out and run like a sob all the way to wot and then it will idle fine till I kill it agian and restart it. Ive changed the spark plugs and put a new yamaha fuel/water filter on it and still seems to do it, I might just need to clean the carbs out anyone else have this problem or any ideas

[Rich Z]

The carb motor also have a lift pump. you may want to check that out.

[Superchamp05]

I removed and cleaned everything ! have a tourney this weekend gonna check it out ! Thanks to all !