Merc bogs on accel then fixes itself

[schmoedog]

I have a newly rebuilt 1979 Merc 115. It starts fine,it idles pretty good (I haven't fine tuned it all yet) but on acceleration it starts to bog down at about 1/4 throttle for a couple of minutes then fixes itself then it runs fine at all speeds until I stop again. Since the power head is new I have been running double oil. I'm on my second tank of normal mix and it still does it. Any thoughts? Fule starvation or timing? Also I'm not getting the high end I expected. I'm running it on a 16 foot Wellcraft trihull and topping out at about 38 mph. I have a 19 stainless prop. Thanks

 

[Bob_VT]

Re: Merc bogs on accel then fixes itself

How are you getting to 1/4 throttle? You should hammer the throttle down to the plane and back down to it. It sounds as if you might have to clean the carbs too. Bogging down might be too much gas and your flooding it out.<br /><br />Bob

 

[wet dog]

Re: Merc bogs on accel then fixes itself

I had that same problem after rebuild. too much oil, had to clean the carbs really good.

 

[Gold Bear]

Re: Merc bogs on accel then fixes itself

Schmoedog,<br /><br />See if your idle circuit is lean. That can cause the problem you are describing. Turn your idle screws out 1/4 turn and see if that helps (test in the water). If not, try another 1/4 turn. If there is still no change put the setting back to original.<br /><br />Good Luck, Gold Bear

 

[schmoedog]

Re: Merc bogs on accel then fixes itself

Thanks ya'll. Goldbear wins. My mechanic told me the same thing. Now it runs like a new one