Merc 170 Stumbles on take off under load

driver26

Recruit
Joined
Jun 9, 2003
Messages
2
I have an '86 Mercruiser 170/ Alpha One 19" pitch prop that stumbles and sometimes pops back through the carb when you accelerate under load. (pulling up skier, going up river)I just did the electronic ignition conversion and that's about it(new to me boat). This problem was happening before to conversion but it idles much better now just stumbles and bumbles sometimes. I am planning on doing plugs and wires and new coil. Since that probably hasn't been done in a while, what next? Rebuild the carburator? Maybe timing? Any help would be great.
 

KCBINWV

Recruit
Joined
May 28, 2003
Messages
5
Re: Merc 170 Stumbles on take off under load

Sometimes timing could cause this. I had the same problem on my mercruiser. When I was coming up in RPM while planing off, if I goosed it around 2000 rpm, it would really hesitate. This would even occur without a load (skier). It acted like if it would get worse, it would backfire, but never did. I got a timing light and reset the timing and the problem went away. I don't know if this is the problem, but its worth a try.
 

horndog

Petty Officer 1st Class
Joined
Aug 6, 2002
Messages
279
Re: Merc 170 Stumbles on take off under load

either the timing or the carb accelerator pump needs to be adjusted or both
 

pshead

Recruit
Joined
Jun 10, 2003
Messages
1
Re: Merc 170 Stumbles on take off under load

Get a Mercruiser Accelerator pump and install it.<br /><br />I "chased" this problem with the aftermarket carb kit and finally got the Mercruiser Accelerator pump and it works perfect now.
 
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