Carbs don't need cleaning?

[davejohnson]

I was having some problems at low RPM's with my '78 inline six. Stalling. It would idle very nicely forever, but stall when I nudged the throttle forward. Thought it was bad spark or fuel delivery. So, my last effort was to try and adjust the idle upward a bit.<br /><br />Throttle cable and gear cable go into the motor through a rubber boot on the port side. There's a threaded bit that passes through a brass sort of barrel, held immobile by a plastic clip. Undid the clip, spun the threaded barrel three or four times clockwise, reseated the brass parts, and the idle came up a bit. Now, no stalls around the dock, and it putters in the no-wake area very nicely.<br /><br />Question: my thought all along was that the carbs were gummy. Is it true that if the motor will idle, then the ports are clear? Seems logical, but this motor defies logic more often than not.<br /><br />Thanks,<br />Dave

 

[JasonJ]

Re: Carbs don't need cleaning?

Generally, any gasoline engine has a tendency to want to stall when pushed to work off idle. That is why there were accelerator pumps on automobile carbs, to give it that extra bit of gas to assist with acceleration at off-idle. It has been my understanding that with Merc inlines, enriching the idle circuits a bit helps with that off idle stutter. My 1250 wants to stall when I pop it in gear, but I always get it in gear and give it a goose of throttle to overcome that sudden load that the engine sees when put into gear. 2 strokes have great upper end power, but they have crappy low end torque, so it isn't a big surprise when they want to stall when put in gear but not given addition throttle. The motor should idle around 800 rpm in neutral, and around 5-600 rpm in gear. In answer to your question, if it idles good, and provides good power throughout the rpm range, then it is highly doubtful that the carb is dirty. Your problem is more of an adjustment/settings problem. Good luck....

 

[davejohnson]

Re: Carbs don't need cleaning?

Appreciate it, Jason. Excellent plain-English reply as always. Cheers.<br /><br />DJ

 

[Clams Canino]

Re: Carbs don't need cleaning?

Perfect J. (take all 3 screws 1/4 turn out)<br /><br />-W