Poor Fuel Mileage

[Guest]

Ok Wing gurus. I have a 85 Interstate. It is getting about 33 mpg. I bought and synced the carbs. Still getting 33 or so mpg. When I was syncing the carbs I had pulled number 3 spark plug wire and left it off. Set the sync tool and started the bike. All with #3 not connected. Started and ran same as when it was connected. Shouldnt this have caused the engine to run rough? This bike is new to me (1 month) so maybe Im not getting fire on all cylinders? That would explain no change in running? I am grasping here, please bear with me. Is this normal for no change in running if #3 disconnected? Any other ideas for poor fuel mileage? I have checked fuel hoses, seem to be ok. Going to change anyway. What else can I check? Thanks

CR

[William_86]

hi, the the carb synchronizer tool is basiclly a vacuum gauge, no matter if the engine is firing or not, the cylinder is still working and pumping, thats why you may not notice a change on the tool. yes it will run rough but the vacuum will be the same.

the engine should sound different when you pull the wire, but if the engine sound doesn't change then you may be having a problem there, try swaping the sparkplugs and check the connections of the wires, if it was the coil, both 3 and 4 cylinders were not working as is the same coil. so i think the problem begins after the coil

[MikeM]

Check compression with all four spark plugs out and throttle wide open. Also while doing the compression check, stick the #3 spark plug back in the wire and lay the plug on the valve cover. While cranking the engine for the compression test look to see if the plug is firing and a good blue spark. If good compression and good spark then #3 is not getting fuel.

[Guest]

After finding my compression gauge, found out it would not fit. So I could not check the compression. BUT I did check all 4 plugs for spark. I am getting spark, but I dont think its very good. Had to shield the spark plug to see the spark. What would cause all 4 to be weak? I have not tested any further as I need to remove the top cover. Also I have noticed while riding that the top cover gets almost to hot to touch on both sides above the engine. Is that normal or a by product of weak spark on all 4 cylinders?

Thanks

CR