Merc Misses past idle

[dstuard]

Well I finally have fire on all six now. Replaced the switch boxes. When I went out to test it, I did not have full power. Idled as good as could be. It was like it was bogging down and missing at the same time when I went past idle. It really was more like a surge in power than a miss though. I am thinking that my carbs are due a cleaning. I know I ran some bad gas in it when I first bought it and it has never really run right. Would anything else cause these sudden surges? They don't last long. They are just like a miss but I can feel the surge rather than the miss. <br /><br />Same old 83 Merc 115 HP that will run right if it kills me.

 

[Yepblaze]

Re: Merc Misses past idle

Yea, pull the carbs and make sure the jets are fully open by holding them up to the light and perhaps probe them with a piece of wire.<br /><br />Do the fuel pump(s) with the kits that include the check valves.

 

[dstuard]

Re: Merc Misses past idle

I did a fuel pump rebuild but did not replace the check valves. I have been wandering if that has been my preblem the whole time. I know it is not working properly b/c it is not replacing the fuel in the filter as fast as it is leaving.

 

[dstuard]

Re: Merc Misses past idle

Took it to the lake today to try and make sure it was a carb problem before I started pulling them off. Misted the carbs and it made it run worse. Got home and took out the plugs. Two were pretty black and there was lots of carbon on them. They are only a month old. My question is will a spark plug make me miss only when I have it under a load? When it finally planes off it runs fine right up to full throttle and then starts to miss. Planning a decarb and a new plugs for tomorrow. Anyone have any other ideas?