great gas miles on road trip

[yamahansolo]

i road to p-cola this week and back...

at one fill up in alkabama i got 42.6 mpg, at another on the way down i got 42.3.
typically i get about 38 mpg. the only difference is i just did an oil change before i left and put in the rottella 15w40 $11.00 at wally world.
part of the trip on the freeway i only got about 39 mpg but i was doing between 85 and someother number
these bikes are so great on road trips! and i always have people comment on how good it looks for a 30 year old!

[CatatonicBug]

Wow! Good for you! Maybe I'll get that kind of luck next weekend on my way to Kansas City!

[XJOK2PLAY]

Yamahansolo,

Have you done much prior work to your carbs?

I keep hearing that drilling the stock airbox, adding a Dynajet kit, and lowering the needles 1 notch is the trick to getting these ole bikes to achieve those MPG figures. Just curious... and congrats on awesome mileage!

[81xsproject]

That is not it. If you want to get great mileage, bite the bullet and replace the needle jets and jet needles. Wear on these two parts as the latter slides in and out of the former causes midrange richness.

[XJOK2PLAY]

That is not it. If you want to get great mileage, bite the bullet and replace the needle jets and jet needles. Wear on these two parts as the latter slides in and out of the former causes midrange richness.

Would you happen to know what the average MPG was when these bikes (XJ's) were new? Just wondered if mid-40's were the average then, and as they wear, mileage drops to low 30's at best? Do you recommend staying w/ stock needles/needle jets, or something different?

Not sure if some friends of mine had that done to their carbs as well, but they also are getting around 40. I'd love to get there!

[DiverRay]

The gas formula is different between the late '70's and now. I used to get mid 40 ALL the time, and NEVER had a tank below 39, no matter how hard I rode. Now, with a lighter bike, I'm lucky to get close to 38. The ethanol and oxynators they have added to the gas produce MUCH less power per pound. That translates to less miles per gallon.
Do keep in mind ALL the XS11 versions are designed to run on REGULAR fuel. If you run premium all the time, you WILL carbon up the heads, as the fuel will not burn as fast.

[yamahansolo]

the carbs have been cleaned once since i have owned the bike and it's been rejetted... but i will have to agree about the ethanol... i read several research articles on ethanol a few years ago and gas mileage suffered on all the tests. maybe i got lucky and found a gas station that had no ethanol mixed in...???
all the ones around here seem to have the 10% ethanol stuff...

i think i gased it up on the way there at the flyin j off of exit 158 or so on i-65 in alabama that one netted me the 42 mpg, and then i filled up on the way out of gulf breeze and netted 42.6

[81xsproject]

Surely you have taken a look at your plugs just to make sure it's not too good to be true. All the mpg in the world won't buy you new pistons.

[Steptoe]

been thrown into a tailspin

hey Diver,just about every adviser I ask down here,,I always get 2 or 3 opinions,,, will tell me to bash regular[unleaded down here] and ethanol fuels in preference for premium fuels because it will burn better, you may run diff fuels to us,perhaps a chemist could help on this one

[Crazcnuk]

Regular gives the most horsepower/fuel economy. Premium burns slower, giving less power, but it's less prone to ping or detonation on engines that need it.

If you have a regular fuel engine that runs better on premium, it isn't tuned properly, pay particular attention to timing (too much adv) and/or carbon build-up in the cylinders.

[trbig]

I know it sounds backwards from what you've always heard probably, but Crazcnuk is correct. Premium is less powerful gas and should only be used to keep the engine from knocking if it is higher compression than normal.. usually something above 10 1/2 to 1 ratio.

As for the ethanol gas, at some points, I think my bike is lean, but in the midrange, I think it runs rich. On regular gas, I can feel much more power, but on a 10% ethanol gas, I get better mileage. The ethanol gas tends to lean out old carbed motors just a bit and I usually pick up a few mpg running it.

Tod

P.S. I have been in Pensacola and Destin for several days, but didn't happen to see any 11's. Headed home today though.

[yamahansolo]

my plugs are fine... plus if i was lean i would notice the detonation... especially when hammering it up the freeway....

it could have been the led lights i installed out back... i think they add 5 hp and 4 mpg to the bike