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Murcury 2 stroke 9.9 hp runs a little rough

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Ahlstrol

New member
I have a Murcury 2 stroke, 9.9 hp outboard motor with a WMC5A carburetor that seen to run a little rough. The motor has about 20 hours sense new and has been in storage most of the time. The motor start good on first pull and run good at both idle and high speed, except for running a little rough. I pulled the carburetor and cleaned it, but that didn’t seem to make any difference, before I pulled the carburetor I cleaned the fule tank and filled it with new gas/oil mixture. I adjusted the idle mixture to the point it starts and idle the best. I pulled the pluges to check them for gap I notice they seem to have oil on them, so I replaced them, no noticeable difference. I am beginning to think this running a little rough is normal for 2 cycle engine. Any body have any ideas?
Thanks Larry
Sent from my Ipad
 
Probably buildups in the carb from gas evaporation while sitting. You could try running a fuel additive that is advertised to clean the carb and fuel system. I'm 70 and been running outboards since 1955. It's the fuel system/carb 99% of the time. Gasoline, today, is terrible. It may burn clean, but it breaks down rapidly compared to fuel when I was young. I always use a fuel conditioner.
 
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