Aftermarket MPG [ Archive] - GasSavers.org - Helping You Save at the Pump

Question, what can I do/buy for my bike to increase gas mileage 2001 cbr f4i, over stock. Will changing to nicer/aftermarket spark plugs, wires, and filters increase my gas mileage or will it just increase my horsepower. Will a slip on increase anything mileage wise. I hope someone has answers, what in general besides better oil can I do to my bike to get more gas mileage not just more horsepower or does it all go together more horsepower = more mpg.

Thanx

OEM components are pretty good on Japanese production motorcycles.

Various emission mandates have made the fuel injection relatively lean which will be good for mileage.

Will a slip on or an aftermarket exhaust help mileage? Unsure.

You could go to a 520 chain (lighter) and differnt sprockets for better gear ratio for your application.

more power (low end tho) plus bigger sprockets to gear it down

Gearing it down will be bigger sprockets in the front (counter shaft), but smaller in the rear. One can do both or either. Really depends upon what you're looking for.

The problem is what the motorcycle was designed for. Your bike is designed to make a lot of horsepower out of a relatively small engine. The way manufacturers achieve the tremendous performance from these motors is making all of the engine systems work at peak efficiency at a high rpm. The intake, the cams, the pipe are all tuned to produce maximum horsepower beyond 10,000 rpm. What that means for fuel mileage is at low rpms the engine is much less efficient. The intake is to large, the cams have too much lift and overlap, etc.... A complete pipe or a slip on may lean out the mixture, thereby increasing your mpg, but it might make the bike run so lean it will require reprogramming the fi. I have had slip ons that just plain made the bike noisy and caused it to loose hp. No gains. My best guess would be 1) light weight synthetic oil (within manufacturers specs) 2) slow down 3) read the websites that deal with your bike and see if any slip ons or pipes add performance without reprogramming the fi (I put a full Muzzy on my Kaw and the hp went up and the mileage went up slightly) 4) realize your bike was meant to excel at a different kind of performance than what you are asking it to do.

Actually, they are much more efficient at lower RPM's. But by spinning the motor way above its most efficient RPM, which is substantially below redline, they can continue to make more power. Might be at 60% efficiency at 13k, but it's jamming so many power pulses in, it continues to make power.

Really, one would need a dyno with a "sniffer" to find out where the AF is. Lots of bikes seem to come from the OEM a little lean on the higher revs and some times a little fat in the lower revs.

Problem from an efficiency point is that most fuel injection programers, Power Commander, Techlusion, etc., can't take fuel away, they can only add fuel.

An air box with longer intake runners is going to give you more low end power, same with a smaller around exhaust, most after market exhaust systems are designed for more power at high RPM and often require the idle to be bumped up as the engine will often hardly run at lower rpm they also can make it really hard to ride the bike around in town because of the lousy low end power.
Touring tires are often longer wearing harder rubber then high performance tires but should still give you plenty of traction if you fallow the speed limit and ride at safe speeds.
New spark plugs are often a good idea in a motorcycle because they wear out fast (more revs, high heat).
O-ring chains keep the grease in so they last longer if you tend to ignore lubing them but non o-ring chains are much lighter for the same braking strength.
If you find that you spend alot of time in top gear then you might want to go with the next larger size sprocket in the front, I just did this the other day and the change is amazing.
Don't over inflate motorcycle tires! but do make sure that they are pumped up as under inflated tires are almost more dangerous on a motorcycle.
I have a pile of K&N filters that I stopped using on my motorcycles because of the amount of dirt that they let pass, I switched to foam filters and found the performance to be the same but that my intake and oil stays alot cleaner.

An air box with longer intake runners is going to give you more low end power, same with a smaller around exhaust, most after market exhaust systems are designed for more power at high RPM and often require the idle to be bumped up as the engine will often hardly run at lower rpm they also can make it really hard to ride the bike around in town because of the lousy low end power.

O-ring chains keep the grease in so they last longer if you tend to ignore lubing them but non o-ring chains are much lighter for the same braking strength.
Sorry to micro manage this thread, but some of these things apply to what I do so...

The F4i has a pressurized air box. It's pressurized from the ram air system. Actually, it's very, very, very hard to improve upon.

Aftermarket exhaust? They will bolt on fine and work very well. HP increase? Honestly, if there was a 1-3HP increase on a system on top, I'd be surprised even after the fuel injection was tuned in. Might do a better job of cleaning up the middle RPMs and even small throttle openings. Weight loss might be the biggest gain, but I don't remember the F4i's having a catalyst with a lot of weight.

Non o-ring chains are only slightly lighter. Additionally, very quickly, they loose their lubrication and begin to actually heat up and rob power through friction.

I might think about using a non o-ring chain for qualifying (a handful of laps), but, after that, it would cause frictional problems that an o-ring or an x-ring chain would not cause even over a long period of use.

i ride a honda valkyrie, and have found the biggest gain in mpg depends on how you treat the throttle. most guys average 33-40 mpg. I average 45- 50 mpg by riding smoothly and staying at the speed limit

I wish that Honda would make a fuel economy, Atkinson cam for my XR650L. Then I could reduce pumping losses without lugging the engine.

what is the best size sprocket size to get to increase mileage, any specifics on how many up or down in the back or front?