Fuel Economy

[El Bandito]

Greetings, and thank you BanditAlley, for existing!  

I just bought a 97 1200s and am thoroughly in love.
It's virtually impossible to keep me off of the damn thing!

But my only question is one of fuel economy..

I'm finding that my mileage is sucking in comparison to what I'm reading that I should be getting..

As far as I know, the bike is dead stock.. well, it appears that way..
it's got the stock can on it, so I assumed that I have no reason to belive that the jetting has been messed with.. and I seem to only be getting about 100 miles out of a tank!

this can't be right.

Also, when i bought the bike (about 300 miles ago) it was suddenly dead one day.. just plain wouldnt start.. and after trying everything i could think of,, i finally pulled the plugs and found them totally facocked.. but they also looked like they had been sitting in there since the factory in 97.. so i didnt pay much attention..


any thoughts? i suppose i need to get in there to look at the jetting, so can ya'all tell me what the stock set up is for this bike??
are the needles adjustable? jet sizes?

thanks!!

[99er]

If the plugs look original, the filter may be as well. This is a carb bike so a clogged filter WILL lower mileage. Check that first. We can't assume stock on any Bandits. So many are modified.

Answer some questions for the list:
1. How many miles on the bike?
2. How many teeth on the front AND rear sprockets?
3. When you say a tankful, do you mean to empty or to reserve. 100 miles to reserve IS low (about 3.5 gallons). 100 miles on a tank is obscene.
4. Original mains (at least on my 99) are 102.5.
5. Does it hesitate around 4-5K? If so, chances are that the needles have not been raised. Raising them one shim too much means about 5MPG lost. They should be lowered until hesitation is seen and then raised one shim. The former owner could have raised them too much.

On a stocker, I would expect 40MPG, depending upon altitude and wheelie habits. There were times that I got 45.
Marc/Atlanta

[PitterB4]

One quick way to see if the jetting may have been messed with is to see if the brass plugs that cover the a/f screws from factory are still there.  If someone's messed with the jetting, they likely drilled them out to adjust the mix.

[El Bandito]

Answer some questions for the list:
1. How many miles on the bike?
2. How many teeth on the front AND rear sprockets?
3. When you say a tankful, do you mean to empty or to reserve. 100 miles to reserve IS low (about 3.5 gallons). 100 miles on a tank is obscene.
4. Original mains (at least on my 99) are 102.5.
5. Does it hesitate around 4-5K? If so, chances are that the needles have not been raised. Raising them one shim too much means about 5MPG lost. They should be lowered until hesitation is seen and then raised one shim. The former owner could have raised them too much.


Marc/Atlanta

#1 about 10k
#2 rear sprocket is a 45/530 (havent opened up the front yet)
#3 i havent done a real scientific test to get an actual number, but it seems to be around 100 BEFORE reserve! (ie. i've filled the tank 3 times (just after hitting reserve) and ridden roughly 300 miles
#4 havent opened up the carbs yet..
#5 I dont notice any hesitation at 4 or 5k, as far as i can tell, the thing takes off like a bat outta hell.. but then again, I'm used to 30 year old honda 750's...

the brass plugs in the carbs seem to be intact. (i assume those are the small (1/4" dia. hole/plugs toward the top of the carb just under the top cover?)

I haven't looked at the air filter yet, and that will be the first on my list of things to check,, but can a dirty filter really affect economy that drastically?


thanks for the help guys,, does any of this raise anymore eyebrows?

[99er]

The plugs are on the base of the carbs, closest to the intake boots. There is a pin hole in the center of each - that way you will drill the proper plug. If they're covered, you very likely have a stocker and can start with a known carb condition - yahoo!

Any carb is jetted based upon a clean intake filter. Once it clogs, the intake draw will increase at the carb jets and will draw more fuel. Air velocity plays the primary role (venturi effect), I know, but a clogged filter will play a role in a carb engine. Fuel injection with O2 sensors will automatically adjust so don't let Fram tell you your injected car gets better mileage wilth a new filter - at least that's my line.

We used to have a lister that got 100 to reserve but he had 1 less front sprocket tooth and a ham fist. You should be getting 120 or higher in Cleveland.

[Red01]

The plugs are on the base of the carbs, closest to the intake boots. There is a pin hole in the center of each - that way you will drill the proper plug. If they're covered, you very likely have a stocker and can start with a known carb condition - yahoo!

And they're on the BOTTOM, just forward of the float bowls.

Just curious, when you hit reserve at 100 miles, how much gas are you putting in? Should be ~4.0 US gallons. If it's much less, there's a possibility the tank has been dented and repaired.

[El Bandito]

The plugs are on the base of the carbs, closest to the intake boots. There is a pin hole in the center of each - that way you will drill the proper plug. If they're covered, you very likely have a stocker and can start with a known carb condition - yahoo!

And they're on the BOTTOM, just forward of the float bowls.

Just curious, when you hit reserve at 100 miles, how much gas are you putting in? Should be ~4.0 US gallons. If it's much less, there's a possibility the tank has been dented and repaired.

All the plugs arein tact, as from the factory! woohoo!
pulled the air filter today, a K&N to my surprise,, was a little dirty but "recharged" it, so we'll see what happens..

also, i just hit reserve last night and when i fueled today, it took exactly 3.5 gal..  

thanks for all the feedback guys!,, but now i think im a little more confused because everything appears to be stock!

[99er]

Wow, I can't imagine putting a K&N in a stock configuration, already lean, and still being able to run at full throttle. Someone must have gone up a couple of steps on the main or at least raised the needles. I would DEFINITELY get the carbs out and check the mains and pilots. If they went high on the mains and on the needles, mileage would be crap (as well as acceleration).
Easily done by pulling the tank, loosening the clamps, and twisting the carbs (cables intact) to rest upside down in the bike. Work from the top. You can use a $10 impact driver from Autozone to get the bowl screws out. You'll get much tech help on this list
Marc/Atlanta

[El Bandito]

thanks man,,
ill get into the carbs and see what's goin on.. stay tuned, if they're not stock, i'll need some help getting this thing together in a way that actually makes sense!