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[ST] Mileage Personal Observations



Mileage...  My personal Observations:  Rather long

A couple of weeks ago I was struggling with finishing my 36000 miles service
on my '99 ST.  Thanks to those who answered my questions, it helped me
finish.  I did the valve adjust and the throttle body sync as well as many
other items. Taking the bike to work and back is 100 miles (all numbers US)
and returned hand numbing vibration and mileage South of 40MPG.  So I took
everything apart again and redid the valve adjust.  Found that I had
miss-measured a valve that was a bit tight and put in the proper shim.  Ran
to work again.  The mileage was a bit better, but the vibration was still
there and I had a high idle?

I push the other bikes out of the garage and find a spring on the floor.
Where did that come from?  It seems that when I had done the Throttle body
sync, I had removed the idle air control valve to get to the adjusting screw
on number one cylinder and when you turn the key on and off (every time the
engine dies during the sync process) the piston can pop out of the assembly
and the spring flies through the air.  Reassembled the parts correctly and
redid the sync.  Ran to work again.  Idle was back and mileage was a bit
better but still not right.

Only other things i could think of to improve mileage were clean the
injectors and clean and lube the chain.  So I filled up with a couple of
tanks of Chevron and spent some serious time on the chain.  I'm on my trip
now and for the first four tanks I filled up with Chevron fuel and the
mileage improved dramatically.  The first 700 miles return 50+MPG.  I spent
12 days on the road, 5675 total miles and had an overall average of 49 MPG.
I had a high of 65.5MPG between Redmond Oregon and Klamath Falls Oregon
(must have had one hell of a tail wind!)  My low of 36.7mpg was between
Fernley Nevada and Austin Nevada (I know I had a head wind and at 90MPH I
only passed three cars in 140 miles).  Vibration was back to normal for the
whole trip, that is, present but not particularly bothersome.