gas mileage/setting valves

roger 04 rt said:

Here is a good list of the things that effect fuel economy: Fuel Economy Factors.

The things that jump out, worst case:

Winter vs Summer Fuel: ~3 - 8%
Winter vs Summer Air Drag: ~5 - 13%
Headwinds: ~2 - 23%
Speed (70 vs 55 mph): ~25%
Acceleration Rate: ~12 - 20%
Idling/Warmup Summer vs Winter: up to ~20%

So if your usual mileage is 41 mpg in the summer, in the winter you could see 5% for fuel, 8% for drag, 10% for headwinds and 8% for other or about 30% worse mileage on the wrong day. 70% of 41 mpg could bring you to low 30s or lower.

Click to expand...

Thanks for the responses. I thought perhaps I might have done something wrong, but apparently not. The bike is running beautifullyand surge is virtually absent.
Anyone out there heading for Americade? Lake George is gorgeous this time of year.

98 r1100rt

A buddy has an 1150 and runs the valve clearance tighter than stock by 2/3.
And seems to get some result he likes.

I experimented with this on the 1100 and found that it increased peak power maybe a perceptible amount at the top of the rev range.
It sagged everywhere else, and became more sensitive to conditions contributing to surging.
I did like the nearly-no-rattle sound of the motor when set this way, I admit.
I should also mention that some forum members cautioned me that the exhaust valve in particular may run hotter than it is supposed to.

Since returning the clearances to stock I have been a lot happier with the motor.
It runs cleaner and pulls harder at low to mid RPMs, allowing earlier (less clunky) shifts.
And is much nicer on parking lots now.
Over the years I have become proficient at getting them set where I want them.
The main problem I had initially is not getting all four exhaust and all four intakes set the same, mostly due to ineptitude with the feeler gauge itself.

I have read somewhere that increasing the lash above stock can give a boost to low-end grunt, similar to putting the GS/R intake tubes on.
I have not tried it, if I did I would try 4/3 of the stock values.
I would surely only embarrass myself trying to explain why this would do anything useful.

I would not expect bulk fuel consumption to change much.
I guess it is reasonable to assume that opening the valves later means they are closed more of the time, consuming less air, and therefore consuming less fuel as well.
But that's kind of a chain of assumptions.
I get around 46 MPG but it varies with weather and mood.