Poor Fuel economy on Gl 1100

[bjcrit]

I have an 81 GL 1100 STD and have been riding to work for better gas milage. She runs fine, no back fires, no missing, smoth as can be. Easy starter.
When I recently noticed I'm only getting approx. 10 mpg or less. 5.3 leter tank, I can go 150 miles then reserve.
Obviously, new plugs, filters (oil and fuel), timing, valves.
Anything else I should be looking at?

[WingAdmin]

Actually it's 5.3 gallons, not liters. And 150 miles on 5.3 gallons is 28 mpg, not 10 mpg.

On the highway, I could normally get 45 mpg, or about 225 miles on a full tank. In the city, 30-35 mpg would be more common.

The standard things you listed - tires inflated, air filters, etc. will all help get your mileage up.

[bjcrit]

Sorry for the miss information.
Do you think the carbs need to be syncronized?

[WingAdmin]

In my experience, the only time carbs DON'T need to be synchronized, is when they've JUST been synchronized.

Yes a carb sync can help increase mileage. And you'll love the smoothness it creates. You can't hurt anything by doing a carb sync.

[bjcrit]

Thanks again for the info!

[dnehasert]

Is it running rough ? A bad coil will cause poor mileage, check coils and wires.

[bjcrit]

Not at all, idles great, no back fires, quite responsive to throttle, starts easily.
How would I know if the coil is bad?

[dnehasert]

A quick would check the coils , wires and caps. Measure across #1 to #3circuit cap to cap. Same on #2 to #4. Using an ohmeter you should read over 10,000 ohms, resistance of the pkug cap. If an onfifite reading then you have an open circuit. Could be coil ,wire or plug cap.

[dingdong]

150 miles at 4 gallons (one gallon left at reserve) is 37.5 mpg. I'd say that is pretty good for commuting. Won't hurt to sync but I'll bet you see no difference. Pull and read your plugs that will tell you if there is a problem.

[seabee_]

How about the air filter. You made no mention of that. If it's old or dirty that will affect the fuel mileage. Bad filter will cause less air and more fuel used.

[bjcrit]

Thanks for the info guys;
Filter just done and plugs are all the same greyish brown color and dry, but I will replace them anyway. I have about 4000miles since last change.