1985 90hp decarb questions...

TBarCYa

Senior Chief Petty Officer
Joined
Apr 13, 2005
Messages
781
Today I decarbed my engine for the second time. After the first time, it ran much better but sounded like it had a miss. Today, I ran it for a couple hours and had a miss late in the day so I decided to decarb it again. My question is when I was spraying the Seafoam into the carb throats, the upper carb caused the engine to stumble and slow while the lower carb didn't have as significant of an effect. Does this mean that the upper cylinders have more carbon buildup than the bottom or is it meaningless??<br /><br />I had been running this engine with 87 octane gas and 40:1 QuickSilver oil and I'm wondering if I should move up to 89 octane with this engine?? I've already switched to 50:1 mix per the manual.<br /><br />Thanks.
 
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