MPG and modifications poll

[dbeardslee]

A recent thread got me thinking about mileage, and the corresponding affect of modifications to the stock setup. Due to limitations in the number of options available I selected 35mpg as the cutoff. I would have liked to add 'riding style', but alas, I've used up all my questions. Hopefully this will still be enough info to draw some conclusions. Heck, jumping to conclusions is the only excercise I get anymore.

[Dennyz]

My 'F' has exhaust, intake and jetting modified. If I drive it fast, I get around 35mpg. If I drive it slow, I get over 40mpg. I usually get around 35-38mpg.

I am a "double the recommended speed" cornerer and don't waist any time getting back to the speed limit (usually 5-10 over), if I ever drop below it.

I went on a 480mi ride with Meri. Being a new rider, she is very cautious on the corners and very rarely exceeds the speed limit on the straights. If the corner is marked 35mph (yellow sign), she does not exceed 35mph. This is OK, she's learning. No one should ever feel they need to drive faster than they are comfortable. On this trip I did my best to match her riding style. At one fill up I go 41.6mpg. I could not believe it. I though I made a math error. The next fill up I go 41.2. I did not know my XS could get that good of mileage.

A couple of weeks ago when the group (go fasters) made the run up around the Olympic Peninsula. Same kind of weather, same kind of roads. Different riding style, I got 37mpg.

I know if a I get on the slab and run at 70+, my mileage will be down to around 35.

Riding style is everything, if the motor is setup correctly.

[Bigfoot]

Fully dressed stock XJ. Loaded down and driving fast I was still getting 37 - 38.

[olebiker]

I did assume you are talking about an American gal.

[dbeardslee]

I did assume you are talking about an American gal.

Ole - I just can't get any mileage out of them

[SFSPECBIKER79]

1979 xs eleven special complete stock factory setup 26000 miles

i got 49.1 mpg running 60-65 mph today open highway high humidity,overcast,s.c hwy 11 scenic route nice country.

[daddyp]

I wonder if the PO of my bike jetted the carbs. It's only had 2 tanks of gas to go by; but, I am lucky to get 31mpg. The bike has a K&N filter in stock box and an Accell ignition, coils & wires. I haven't pulled the plugs to check for carbon or proper gap but she does smell a bit rich.

[Geezer]

The Mongrel I sold last year (half special and half standard) only got abut 35 MPG on the freeway with Harley mufflers and UNI pod air filters. I know there was something wrong with the carbs but it ran so good, I never felt like messing with it.

The 79 standard I have now seems to get better mileage but I'm working so much that I rarely get to ride it more than a few miles away. It seems to be getting in the high 20's in town but I haven't checked. The mufflers are shot and rattling and will soon be replaced with Harley mufflers.

Geezer

[GARTHXS]

mpg

My 78e is running a high flow bassani 4/1 mikesxs pods and up three sizes on mains and one size on pilots, I get like 25-30 but extremely quickly , still needs tweeking on sync and mix but runs pretty good with idle at about 1100-1200k

[xschop]

MPG Update

Same engine and carbs with stock xs1100 Final drive= 36 mpgs
" "xs750 Final drive = 42 mpgs
" " Chaindrive (13/42)=38 mpgs

These are averages, the 750 FD is 2.9 to 1 ratio, the xs11 FD is 3.3 to 1.....and the current ratio is 3.2 to 1......seems like getting rid of 2 right bevel drives has another benefit.....chop

[dbeardslee]

Chop - You ever dyno test with the chain drive? I'm guessing that gives you a few more ponies at the rear wheel.

[TADracer]

Two months ago I checked milage over 100 miles of varied riding (interstate, behind school bus, aggressive road riding, etc.) and averaged a shade over 41 MPG. I thought that was pretty good for 79SF with 4-1's, pods, jetted and a few other minor goodies.

[randy]

Consistent mid-40's in MPG with the setup listed below. I find I do best when I avoid 5th gear as much as possible. Well, below 70 that is.

[corey]

79 Special, Jardine pipes, EMCO pod filters, rejetted... its been so long I don't even remember the jet sizes!!! Either way, I get about 32-34 MPG. Close but no cigar!!


I should note that my mileage went up since I fixed my gas filler seal. Evaporation is a mother, ya know?

[dbeardslee]

Corey - I never even thought about evaporation. I guess I should get busy an put the new seal on mine - it's been sitting in the garage for a month. Interesting avatar you selected. Reminds me of my last physical