Rough Idle

[Brisco58]

I have a 1998 150 VMAX. Recently due to a bad fuel tank, I had to take the carb down and clean them thoroughly. After putting them back together and tuning them according to the seloc manual, the motor ran fine on the hose. When I put it in the water it ran fine for a bit, then started to stall at idle. I readjusted the idle screw and the pilot screws by ear because my tachometer is not working. Again it ran fine for a while, but is now doing the same thing again. I have cleaned and changed the plugs multiple times and can see no warning signs from their appearance. I was just wondering if anyone had any suggestions.

Chad,
Englewood, FL

[boats.net]

You are better off setting pilot svrews to 1 1/8 turn on port side and 1 5/8 turn on starboard side. If they need more adjustment then turn all of them 1/8 turn to keep them even. It sounds like you may have gotten more trash in carbs, may have to clean again and install a fuel/water separtor filter.

[Brisco58]

RE Rough Idle

Thanks for the adjustment tips, I will try cleaning the plugs and readjusting. I have only run clean fuel on a new 12 gallon external tanks since I cleaned the carbs. I also ran sea foam through the new fuel. I hope the new adjustments help, the motor is fine at speed, just caughs and stalls at idle. Also, I have never had any problems with the motor before the fuel tank got water in it. I left my baitwell on overnight and filled my bilge with water. I guess the fuel tank leaked on the top somewhere. I appreciate the advice.

Chad,
Englewood, FL

[jb123]

if your gas tank got water in make sure oil tank didnt also....

[Brisco58]

Good thought about the oil tank, but it sits in a comparatment above the bilge. I tried tuning the carbs again and cleaning the plugs, but I get the same result. I guess it is time to take it to the shop rather than risk damage.