Setting idle speed on 150 looper

[Fl_Richard]

I have an OEM manul and I've read the forun to determine the proper way to set the low speed mixture on my 1995 150 looper.

Last week I took it out on the water and while my trusty mate was at the wheel I removed the engine cover and started with #2 carb and began turning the slow speed screw in slowly 1/8 turn at a time, waiting 10-15 seconds and turning in some more. Eventually my wife ran her aground and in the confusion I lost count of the turns I'd made. So I backed it off a few twists and called it a day.

My point is I never bottomed out the screw and I also never got it to the point where it sneezed. Approximately how many turns out is the average running position? I remember reading that 1.5 turns out is the starting position and you adjust from there. I think I turned it in at least two maybe three turns in before giving up and I have no idea how many more twists it would take before bottoming out.

Also is the sneeze definite? I mean will I know it when when I'm at the right spot?

Should I just turn them all in until they seat, back them off 1.5 turns and start from scratch? Or spend more time and slowly crank them in one at at a time?


Many thanks,

Richard

 

[CharlieB]

Re: Setting idle speed on 150 looper

Go to a carb that you haven't messed with, carefully count the turns in until very lightly seated.

These idle screws have a VERY FINE thread, be very careful to use only two fingers to rotate your tool or you will distort the needle and seat turning in with any force.

Tie the boat off to a dock and use a small digital tach to see the change in idle RPM in forward gear. DO NOT TRUST your ears.

 

[ezeke]

Re: Setting idle speed on 150 looper

I regret that I don't have the manual for your motor, but I believe that your initial setting is incorrect and should be 3 turns and possibly 4, depending on the model number. The 1996 motors used 4 turns initially, I believe.

I hope that someone who works on those motors will jump in with the right information.

 

[Fl_Richard]

Re: Setting idle speed on 150 looper

Your right ezeke, just checked my manual. It's three turns to the seat!

As I said I've never turned them in fully. They have always been at the point they were adjusted to when I bought th boat five years ago.

Given I dont know how well they were originally adjusted and the engine has an occasional sneeze at idle do you recommend that I re-seat them all and adjust from the baseline. Or slowly turn each one in until it sneezes then back it off and go to the next one. I cant tell which cylinder is sneezing.

If I buy a small digital tach as CharlieB reccommends am I looking for a slight drop in RPM?

Many thanks!

Richard