40 -45 mpg?

[Guilty]

I don't know why, but my bike seems to have a significantly lower mileage than what is supposed to be. I know what they are rated at is in perfect conditions, but as a daily commuter in town with speeds never getting over 50, I can't seem to get but around 40-45 a gallon.

I've tried using pure I've tried using pure 93 octane fuel at the one shop in town that supplies it without the ethanol, but it didn't really do a whole lot with the mileage. Although, it did seem to make things sound and feel a lot better with acceleration. I have done all of the necessary 7.5k maintenance procedures, oil change, air filter, valves. But it still gives the same amount of mileage as a freaking Prius.

What's up with that?

[jkv45]

Is it possible that you are short-shifting and bogging the engine? That would lead to more throttle-opening than needed, dropping mileage.

Try cruising in the mid-range near the torque peak, allowing a smaller throttle opening but higher RPMs.

You may need to make adjustments to the idle mixture, or sync the carbs also.

Regular 87 octane without ethanol should give you the best mileage.

[dcj13]

No offense intended with any of this:

Are you significantly heavier than the average person?

Do you spend a lot of time idling the bike? (in traffic? or while you're working on the bike?)

Lots of stop and go traffic?

Have you verified that your odometer fairly accurate?

Have you determined your gas mileage by dividing your miles traveled by the exact amount of gasoline you put in the tank? And checked it over several tankfuls? (again, no offense... some guys have made some really goofy assumptions/estimates/guesses about this in the past).
Is your air filter fairly clean?

Does the bike run well?

Do the wheels spin freely?

Do you ride the brakes?

Do you live a fairly hilly area? (like San Francisco, maybe?)

[Brother Michigan]

Just speaking from my personal experience using my 300 as an in-town commuter, that sounds about right. Get out an run a tank through it on some highways, state routes, etc. away from traffic lights; you should see the mileage jump pretty considerably.

[Ghostt]

I average about 45mpg, I have noticed a few more if I use Shell 87.

My weight with gear is about 230lbs and my bike is geared +1/-2

[snot]

any mods on the bike?

[Motofool]

Originally Posted by Guilty

......... as a daily commuter in town with speeds never getting over 50, I can't seem to get but around 40-45 a gallon.........

That is not normal, unless you go through many stops-starts with strong accelerations.

Combined with a leaky petcock, one of these may be leaking when stopped, just enough to be slowly evaporated.

[Alex]

Fuel mileage poll thread here:

https://www.ninjette.org/forums/showthread.php?t=13536

[HoneyBadgerRy]

I weigh 130, hammer the **** out of my bike, and get ~50mpg, so something is likely wrong.

[cbinker]

Sounds normal to me when I had it street legal. -- 6'1 185.

[Sarge1992]

I beat the piss outta my Ninja and get 55-60mpg, granted my valves were adjusted, carbs rebuilt and synced, and full tune up was just done within 1k miles. I also use only ethanol free gas, not sure if that makes much of a difference on carbureted bikes or not. I'm also 6' 180lbs if that helps.

[Brother Michigan]

The biggest difference is the stop-and-go nature of commuting in-town. Spirited riding with infrequent stops is very different from even relaxed riding between stoplights spaced every five hundred feet. See my anecdote above.

[greenaero]

I would check to make sure that your moto is in good condition and everything corrected adjusted ( Valve clearance, carbs, compression, no fuel leaks, etc.). Make sure your chain is lubed and correctly adjusted and that your tires are inflated properly. If everything checks out OK, look at how you are riding your moto; are you riding it hard with high RPMs , racing up to every stop sign ? A rider can burn up a lot of fuel in a hurry if they overuse their throttle. Conversely one can get good to amazing fuel economy if you take a disciplined approach; moderate acceleration to target cruising speed, maintain target cruising speed in the highest gear without lugging the motor, anticipate stops and slow downs and get off the throttle, coasting to the stop. When I hypermile my moto it's like riding a toboggan; maintain momentum, minimize braking , and corner hard. It's all about using the energy you expend to get up to speed and get you down the road as far as possible. Good luck YMMV

[2fiddy-trackpair]

My commute goes like this. About 20 miles averaging 65 mph with a couple of towns where the speed limit is 35 mph. Then about 15 mile of 70 to 75 mph highway driving. I average about 43 mpg. Might need to adjust and synch the carbs.

[Ghostt]

Originally Posted by 2fiddy-trackpair

My commute goes like this. About 20 miles averaging 65 mph with a couple of towns where the speed limit is 35 mph. Then about 15 mile of 70 to 75 mph highway driving. I average about 43 mpg. Might need to adjust and synch the carbs.

Your carburetors are most likely okay, and don't touch the sync!! Vacuum synchronization isn't a true synchronization.

When was the last time you adjusted the valves? Serviced the spark plug caps? Check the plugs?

I have noticed that the brand of fuel makes a difference in my mpg, the best I have found is Shell around here.

[hfd1 tuner]

Originally Posted by Ghostt

Your carburetors are most likely okay, and don't touch the sync!! Vacuum synchronization isn't a true synchronization.

I use the old mercury sync set-up! The new "safe" ones suck butt.... So school me on how to true sync is done? Not too old to learn a new trick but I even sync throttle bodies with my rig.

[Ghostt]

Originally Posted by hfd1 tuner

I use the old mercury sync set-up! The new "safe" ones suck butt.... So school me on how to true sync is done? Not too old to learn a new trick but I even sync throttle bodies with my rig.

Okay, here's my official write-up, and its also the same I did over at ninja250.org

It states the reasons why vacuum method has it's faults, and why.

http://faq.ninja250.org/wiki/How_do_...ch_sync_method

You can sync with the carbs in hand. Back the idle adjustment off to close that carb then match the second carb to it with the sync screw. You can then turn the idle adjustment up while using a thin feeler gauge (maybe .002") between the throttle plate and the throttle bore, adjust to just fit, and then check the second one and adjust to match. If you have good feel for this it will run fine once installed.

It would do folks well to take a minute to review and understand what a sync tool does, how it works. And take another minute to look at the carb linkage and sync adjustments available to fix irregularities that might occur. It can help take some of the mystery out of this as well as stop unnecessary carb sync screwups.

Meaning, that the carbs were right once, the butterflies were matched and it performed well, but then changed. Undecided And the problem somehow occurred in the butterfly direct shafts, or the sync screw turned or wore that pad that it rests on, or the carburetor pairing/ bridging brackets twisted in relation to each other, and enough so that the butterflies no longer operated in sync, such that performance noticeably suffered. And a fix will be accomplished by changing the butterfly position, the only thing the sync adjustment does. Hmmm. Really? Undecided

Meanwhile, the tool measures vacuum at each individual runner. That's all it does, how it works. And vacuum is effected by a huge list of things, butterfly position being only one of them, and the only one addressed with that tool while turning those sync screws. The rest of that list includes, valve adjustment, jetting, float level, compression differences between cylinders caused by wear as well as factory CC differences in the head, intake runner, as well as flow by port variations, etc. Variations in cams, wear or factory tolerance. Then there's the potential big one, pilot jets and pilot screw mixture settings. All of those effect the vacuum and will be read by the sync tool, accurately identifyng the difference that exists, and with the only adjustment being used to "correct" the problem, move the butterfly relationship, one to the next.

It's that clear understanding that has me of the opinion and long time practice to not touch the sync screws on a set of carbs that were right once and were never dismantled from the rack. And jet cleaning as well as float needle changing doesn't require that they be dismantled. And further, if I DID dismantle a set of carbs, I just matched the butterflies on the bench at assembly, using a feeler gauge, and then never touched them again, never gave them another thought.

That method, properly executed, will have THAT portion of the complete equation, balanced flow to each cylinder in a multi-cylinder/ carb application due to butterfly position, satisfied entirely adequately. And in fact, it has worked for me every time I've done it on every bike (as well as individual runner/ butterfly V-8 intakes, all eight) that I've ever owned or any that I've fixed for others. And the times I fixed for others was usually after an attempt by others to sync the carbs, chasing a problem, or sometimes not even chasing a problem, but one they created wth a sync tool, chasing a problem from that list, that was never a butterfly position change problem. Those linkages are so direct and simple that they don't know how to screw themselves up. Not enough to care about.

I'm sure this will start a lot of controversy so I won't argue it, just offering it for those who understand the whole picture that I outlined and might make good use of it. It is what I've done, on every engine I ever worked on, including blue printed racing engines as well as regular old, high mileage street stuff. I've had at least four, four cylinder bikes with over 100,000 miles that ran quite well, the whole time, and never had a carb sync performed. When they did finally get a total disassembly, this is how I set them up, on the bench. Over the years I've straightened out at least a half dozen messed up ones, probably more, and on the bench, after fixing the original problem which was fouled pilot jets.

I only posted this because it seems like its coming up fairly often, especially with problems from a sync gone bad. One I would suggest was never a sync problem to begin with. A big or sudden change in performance is NEVER a sync problem. NEVER. Remember that. Cool If there is a problem, and you connect the gauges? YES, there will definitely be an imbalance indicated. But because that hole has a problem that is from the rest of the list. A bad plug, a plugged pilot jet, a screwed up float, a bad valve or setting, etc. Every one of them effecting the vacuum in the intake but NOT from a sudden move of a butterfly position, a sync adjustment.

[hfd1 tuner]

Yes a sync will not fix a poor running bike due to carb dirty poor compression spark plug dirty tight valves ect. Carb sync is a fine tune thing the LAST thing on the list. It just evens out any weirdness that is just part of carbs and air flow. The main deal is it gives the same pull on the pilot circuit. so in the theory is if the holes are the same size to the pilot you get the same shot of fuel into the intake. The is always a little difference on how one carb works with the other.

[hfd1 tuner]

Yes I start with a dial caliper while cleaning carbs to set the blades the same. I can see if they are off and look for the tell tail signs others have messed with the carbs.