Fuel mileage

[PhredValk]

OK. I bought a 99 I/S last spring and am looking at fuel mileage/performance mods.
I ride to work, the store, wherever when weather permits, and tend to visit Friends hundreds of miles away just for the ride: and ride to Toronto in the summer. I'm turning into a long distance kind of guy, and a few more miles per gallon is becoming important.
I'll do the ECT mod and polish the intakes, but what else?
I'm thinking of 4d trigger wheel, and am looking for a Dyna3000. How much will work, and what combinations are just not worth the effort and cost?
I like the performance of the fat girl (and have the photo radar pix to prove it), and don't want to lose acceleration, but fuel mileage can help in a 5000 mile trip.
Thanx in advance,
Fred.

[Momz]

Phred,

You don't need a 4 degree TW since you've already done the ECT Mod, and the Dyna unit is no longer available. Adding a TW (or the Dyna unit) will give you far too much ignition advance.
 
You could have a Glasspack/Truck stack modification to your OEM exhaust (DragonPacks, Mark Ts, or Viper), the Carolina Bike and Trike mufflers, the entire SuperTrapp system.

A good tune-up with a carb sync and a K&N filter will also help.

Merry Christmas
Momz

[sandy]

Most folks who have polished intakes say it was a waste of time. No changes. As Momz said: Only do one advance mod. ECT, Dyna 3000, trigger wheel (4deg). If you want better MPG's, get DynaJet needles and lean it out a bit. I improved my tourer's after playing with needle settings and resetting the pilot screws. No ign advance options.

[98valk]

ECT mod stops working at 3k and higher hwy rpms. even less for std ICM http://timskelton.com/valkyrie/tech/trigger_wheel_plus_dyna3000.htm  here u can see the drop off before 3k. too much advance 2.5k rpm and less will cause detonation, black spots on plugs.
the dyna for the I/S was never made.
  get rid of the ECT mod and modify your stock TW for 4 degrees for advance.
take the metal screen off the bottom of the OEM airfilter for more airflow and clean air. K&N lets in a ton of dirt. OEM filters last much longer than 12k.
polishing the intakes correctly will net a gain of 1-2 mpg. Correctly is 300-400 grit polish with 60-80 grit on the short radius.
75-90w gear oil in rear drive
either 5w40 syn oil or what I use Amsoil 10w30/30 HD diesel oil, for slight mpg gain.
different exhaust that provides a 3 into 1 collector will always boost torque and mpg.
some have played with advancing the cams for mpg.
calf bike cams will give better mpg but HP will be down about 5 HP.

I use std ICM, OEM TW modded 6 degrees and dyna ICM with -10 degrees advance under 2.5k rpm.
usually avg 38-39 mpg this includes airbox mods and jetting w/glass pack exhaust. straight hwy high 40s to 50 mpg.

[Valker]

...or what I did was save all the money I would have spent trying to get better gas mileage and buy more gas. Honestly, the only thing that has helped on my bike (125,000 miles so far) has been to ride slower. At my normal 75-82mph cruise, I get 30-32 mpg. At a sedate 45-60 on the Blue Ridge Parkway, I got 47-49mpg. Riding pretty slowly through the mountains of NM and CO just sightseeing, I have gotten over 50mpg out of two tanks.

[Red Diamond]

I ride consistantly between 65-70 MPH, get 40 MPG on my '99 I/S, no mods, all stock. If you want to create problems, make all the mods you want and get no better MPG, just more problems. Do the routine maintenance on the bike and enjoy riding it. As was mentioned above, slow it down. My .02 worth.

[Ricky-D]

99 Red Diamond's got it correct!

It's so easy to recognize a good answer!

***

[PhredValk]

Great advice, and in 12 hours. Is this place great or what? Lots to ponder while waiting for spring.
Thanks to you all,
Fred.

[Big Rig]

It also depends on how long you can sit in your saddle before stretching your legs...I am good for about 200 to 220 miles or one take of gas...each stop takes between 20 to 30 minutes...the math says, screw the gas mileage and ride it like you stole it...