Idle Speed Problem

[bm258]

1990 Johnson GT100. I have started having a problem when i am running in forward & reverse at idle speed. The engine almose seems like it is going to shut off. Almost like the enging is not getting enough gas. I just switched to a 19 pitch from a 17 pitch prop. I did not have this problem with the 17 pitch prop. I do not have this problem when running any faster than idle speed. Could the vent holes being open have anything to do with this problem? Thanks for any help.

 

[JB]

Re: Idle Speed Problem

Sounds like the idle speed may have been set when the engine was not under load and on muffs, BM58.<br /><br />Having the exhaust outlet in the water when setting the idle speed is very helpful, as it provides the same exhaust back pressure it will get in real use.<br /><br />Good luck.

 

[bm258]

Re: Idle Speed Problem

Thanks JB. What should my idle rpm's be for this motor it is at @ 1000 right now whils this is giong on. Should i try and get it up 1200 or so?

 

[Dhadley]

Re: Idle Speed Problem

If the carbs are clean and the motor is otherwise healthy, 1000 in neutral, in the water is almost too much. Neutral is usually around 900 or so. Look for 650-750 in gear, in the water. With a healthy V4 cf 550 is not out of the question.