View Full Version : Gas Mieage, This can't be right!!!

21st December 2004, 14:57
I have had my conversion (883 to 1200) done for ohh about a month. I have put almost 200 miles on it in that time. (Its cold here) I had to put gas in the ole girl and doing the math I am only getting about 39 miles per gal. I run 93 octane in it. Or a gal of racing fuel and 2 1/2 gal of 91 (we have 1 place here that sells 93 across town and i was on reserve) Any way is this indicative of my conversion, will it stabalize out, or is my Mikuni to rich? I am not sure how to tune a Mikuni, I have Bassani Pros and I have Thunder Monster baffles ( these thing are so worth the dough)in it. Will I get better gas mileage? What is up? :eek:
Or is it my riding style. Ok yes i did wind 3 gear out to 82 mph once......... ok twice (this is what i looked like :yikes ) Damn shes got get up and go. :D Any help would be great...

Happy Holidays!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!

21st December 2004, 15:05
could just be warm up time eating a little more gas then normal, since there have been some cold mornings in OK lately.

21st December 2004, 15:16
this is common during break-in of a new engine...after my 1200 conversion I was getting about 40mpg...now I'm back up above 50 (if I ride in a sane manner)...I would give it some more miles and keep track of it tank to tank...just to see if it is getting better :)
Hope this helps,

21st December 2004, 15:20

21st December 2004, 22:18
G'day Skip

I would say you have a combination of a few things.

As said ...run it in first.

Your Mikuni is maybe a bit rich and the accelerator pump is probably comin on too early.

The octane fuel you are runnin is probably too high ....go to lower stuff.

now ya got more power you are probably using it (which doesn't help in the acc pump area)........that'll settle as the novelty wears off...

Stephen Hawk
23rd December 2004, 14:39
I wouldn't be concerned about the 40 mpg at this point as the engine is fresh and needs time to break in. Many issues come in to play when figuring gas mileage however, the biggest of them all is run time at a complete stop. When it is cold, the bike requires far more time to warm up and many of us do allow the bike to warm up. While doing this we are getting a big fat zero in terms relative to actual gas mileage. Therefore, if the bike were getting 48 mpg during the warmer months, it is probably getting the same relative mileage now however, it figures to be less because of the stationary run time. Put the bike on a ride log and begin to monitor the mileage. I think you will find things to be quite normal when all is said and done. In the summer months I am filling my 1200R at roughly 125 miles but during the winter months when the temperatures are near freezing, I am filling around 110 miles. Typically the bike is getting about 5 less miles per gallon or 15 miles per tank.


26th December 2004, 15:07
Given the newness of your engine that doesn't sound to bad. My 1200R gets lo-mid 40s usually, but then our "normal" back road speed is in the 85-95 range, and of course any curves require acceleration! When new the engine burned a bit more than now. Given that my other 3 Sportys would all run @ 50mpg, but sustained speeds were @ 70-75 max., the mileage on my 1200R (premium pump gas) seems OK to me. Besides...the bike is so much fun to run back roads with...who cares about a few mpg??! DFO :D

26th December 2004, 15:43
I'm back up above 50 (if I ride in a sane manner

That pretty well sums it up. We have a tendency to want to work the throttle and enjoy the power.

26th December 2004, 16:50
I was gettin about 115 miles per tank. I just ran the first tank through after breaking in the conversion and had to grab reserve at 96 miles. Most of that is hammering though the twisties. Once I get another 400 miles it's off to the dyno for tuning. I don't think I'm too far off but I didn't change any jetting for the conversion since I was pretty close with the taxes paid jetting. I did read that someone went to a 165 main once he got it to the dyno but that sounds extream.

26th December 2004, 17:00
Your mileage will improve as the bike finally gets broke in. 200 miles is far from broke in. give it a few thousand more and then worry if it does not get better. Jetting should be checked also. New motor means new fuel needs.

26th December 2004, 17:01
It ain't no moped but I'm gettin around 42-45 on the open road , in town I get about 4 :laugh

26th December 2004, 17:34
I did read that someone went to a 165 main once he got it to the dyno but that sounds extream.

That's interesting as most of us go with a 175. I disadain dyno tuning in favor of reading the plugs but I'm not much into the performance thing as others.

26th December 2004, 19:11
Will, I used to use a 160 before I switched to the S&S. Every bike runs dif. I also had a dif. needle and dif. screw adjustment. Only reason I switched to the S&S was top end on the autobahn otherwise it rode great with the c.v. jetted with a 42/160 combo. The S&S was also free. I had about every jet size so I could try out every combo until it fealt best.

27th December 2004, 15:34
Lets not forget about the cold weather here. When it's cold, you do let it warm up longer, but that's not the only factor. Cold air is dense air, which means your card needs to add more fuel in order to keep the mixure right. This is true of any vehicle. I would think after break-in, carb tuning, and the return of warm weather, you'll see mileage around what you were expecting.