only 63mpg? How can i increase it

[scorch]

My goal was to get my 2002 ninja to get into the high 90's. I got 60mpg before. Then recently switched to 39 rear sprocket hoping it would increase and only 63mpg riding very leasurely. On my 08, with this sprocket combo i got 89 in the same conditions.

Im wondering if its a carb issue. The tires and all seem to be well inflated etc...

[Alex]

Talk to @greenaero...

[alex.s]

lose some weight

i haven't gotten above 40mpg in years

[NevadaWolf]

Yep, I think anything north of 70 is going squarely into @greenaero's realm. Best i have ever gotten on my stock newgen was high 60's, tend to average mid 50's.

But in this case i know its the rider and not the bike.

[DaBlue1]

Ever considered better spark efficiency as part of the hypermiler solution?

Takai Hi-Output Super Coils

[EMSRacer07]

my pregen with carbs would get 65-70 easy. That is with stock everything and changing the sprockets to 15 front and 42 rear. Really lowers your engines speed. And just watch your throttle. I always stayed below 50% throttle.

If you really want to spend the money on efi kit from ecotrons, I was getting 80-85 with that kit easy. Always puts you in the most efficient air fuel mixture and really reliable.

[scorch]

i dont coils would help too much, specially when they cost 700$.

i filled up my 08 with regular gearing and got 67mpg last week. Ive heard from 08 owners that the new gen 250s get worse mpg, but it doesnt seem to be the case for me. my riding is mostly under 55 mph commuting too.

any ideas?

[DaBlue1]

Originally Posted by scorch

i dont coils would help too much, specially when they cost 700$.

i filled up my 08 with regular gearing and got 67mpg last week. Ive heard from 08 owners that the new gen 250s get worse mpg, but it doesnt seem to be the case for me. my riding is mostly under 55 mph commuting too.

any ideas?

Oh Sh**! you should have said....
only 63mpg? How can i increase it Cheaply?

Where did you get $700 from? They are $409 and $327 on Amazon
Would iridium plugs be too much?

[Ninjinsky]

I usually get 70 -80 (uk) MPG and ride fairly briskly in the 7-10K range.
If you ride too slow,or labor it at low RPM you are not really in the efficiency zone of the engine
It has always been a weird engine to find the sweet spot of in that at high revs it feels like a 4 and at low revs it feels like a single. Never like a twin.

Totally different to, say, the old CB 250 which gave a smooth and steady delivery at low rpm with no schizoid transformation of personality as revs rose.

[scorch]

i havent been slugging it too much. No more than usual anyway.

Could a dirty carb cause a decrease in MPG. im not sure if its the case or not. But my riding habits from the 08 to the 02 are about the same. But the 02 is reving much lower now. so id think it would get better mpg.

Thanks for the feedback. Id like to try nd make this 250 a efficient cheap commuter.

[dcj13]

The difference it cost between 10 mpg and 20 mpg is huge.

The difference it cost between 60 mpg and 70 mpg is negligible.

[greenaero]

@scorch, Step one for good fuel economy is insuring your Ninjette is running optimally: fresh sparkplugs, clean and adjusted carburetors, clean air filter valve lash adjusted ( I keep mine at the max clearances) chain lubed and adjusted, tires to the max recommended ( though I run even higher, ~ 40/40 ) , check wheel bearings and that the brakes are not dragging. After that I had a moto that would break into the low 70+ mpg range but more typically get mid to high 60's. I was a bit disappointed with this but after joining some Ninjette forums I found that most riders didn't even get 60 mpg that often.
Next I began with raising the gearing and found that 15/37 works wells for non-streamlined motos.I broke into the 80-90 mpg range.
Next I enclosed the front fender , made an aero windscreen and installed a tail and with this I began to break pass 100 MPG on good runs.
After that I replaced the stock fairing with a dustbin type that I made myself and replaced the first tail with a larger Vetter-styled tail. With full radical streamlining I was able to raise the gearing firther to 15/33. With this set-up I placed second overall at the 2012 Mid Ohio Vetter Challenge with a 119mpg run. My best run with this setup was 136 mpg.
Next I replaced my Coroplast over sheetmetal dustbin front end with a fiberglass Vetter nose that I bought from my friend and fellow competitor Craig Vetter. My front was not as rigid as the Vetter nose and did not have the best shape as does the Vetter nose. I rebuilt my tail, further strengthening it and making it more rigid and durable by reskinning the plywood frame with doorskin and fiberglass. I took 4th place overall in the 2013 MidOhio Vetter Challenge with a run of 130.7 mpg. My best run so far has been 146 mpg.
So great fuel economy for a few $: keep the moto properly tuned and adjusted, change the front and rear sprockets for taller gearings ( ~15/37 ), install a taller windscreen, and ride efficiently.
Here is a for an article that I wrote that 250 Magazine published that you may find helpful http://twofiftymag.com/2012/11/max-m...rmiling-guide/

[InvisiBill]

Originally Posted by DaBlue1

Ever considered better spark efficiency as part of the hypermiler solution?

Takai Hi-Output Super Coils

Semi-related, has anyone tried adapting a coil-on-plug setup from another bike to work on the 250? I did a quick search but didn't see anything that looked related and just found https://www.ninjette.org/forums/showthread.php?t=118112.

A couple people have swapped COPs from 600/650cc Kawasakis onto the 500, and I have a set ('04 ZX636, same part number as the '05 alex.s mentioned in the other thread) that I'll be putting on mine eventually. I got the 4 COPs and the wire harness for $20 on eBay. It's basically just adapting the wires from the CDI to go into the COP instead of the coil, and possibly adding a resistor.

I realize that they're not high-output aftermarket coils, but COP might be helpful (though I've read that the new COP systems actually put out less power, as they're designed to match up with more modern and precise computer-controlled ignitions which don't require as much). The 500 has some reliability issues with the plug boots and wire ends, so even just equivalent output from a COP system is still a bit of an upgrade for me (though the others seem to find them to be an improvement).

Even if the OEM COPs are only half as much improvement compared to the Takais, there's something to be said for $20 vs. $400. As alex.s said in the other thread, there really shouldn't be a difference on a stock bike, but if the stock ignition is just barely good enough (I have no idea if it's just barely good enough or way more than needed), going to a slightly better OEM ignition could help in the most extreme conditions where the stock system isn't quite cutting it. It sounds like the COP design is just inherently a little better.

Originally Posted by alex.s

the gains from this type of coil comes from the lowered resistance going from the collapsing field into the output coil and into the plug... if you look up joules law you'll see as you lower that resistance, you get higher inductance joules going through the plug for the same amount of charge current (from cdi) which means the spark is hotter and will last slightly longer.

Originally Posted by alex.s

well so if you have a weak spark, you are only igniting a part of the fuel, and then that fuel ignites the rest. if you put more joules through the plug (joules is basically heat... factor of power over time) then the spark contributes to igniting more of the fuel. if you are running very high RPM with high compression (lots of other circumstances but these effect it the most) then its possible to complete the burn cycle while still having unburnt fuel. having a hotter spark can start the combustion faster, which means you are able to get a more complete burn. more fuel burnt, more power output.

[nickjpass]

63 mpg not good enough?

[jkv45]

Originally Posted by nickjpass

63 mpg not good enough?

My SV650 can do that...

[sharky nrk]

^^ I would be pretty happy with 63 mpg, I struggle to maintain 55

[alex.s]

i donno about that alex.s guy. i would just go with stock coils. they're good enough.

[choneofakind]

How much cheaper of a commuter are you going for that 63 mpg isn't good enough?

FWIW, 63 mpg sounds totally normal for average riding. I see nothing immediately wrong mechanically with your bike. I'm able to get ~63 as well on my pregen with mixed riding, no particular emphasis on mileage. I'm a calm/casual rider and I have my fun without always being wide open. But the bike is my toy so I really don't care about the gas mileage. It's just an added perk to riding vs. driving my car, which gets about 27-30 mpg, again, no particular emphasis on mileage.




EDIT: the other thing to remember is the 08+ is intended to make more power in the mid-range. It has cams with less duration and has relaxed ignition timing at about 36 degrees BTDC. Compare that to the pregen, which is tuned for high end power. The pregen cams have more overlap and the ignition timing is advanced at about 42 degrees BTDC. This means that your engine on the '02 will be in its most efficient range at a slightly higher rpm than the 08+ bike. (correct me if I'm wrong)

[scorch]

good suggestions aero.

Today i had a bit of better luck 68mpg. but it isnt very good now that i have 15/38 gearing. and i only filled up because i thought i was running out of gas. THe bike seemed to be have running out of gas, and then i slowed down and it seemed to have fixed it. But it was an odd feeling of the bike struggling as if it didnt have gas.

[scorch]

no 63mpg isnt that good for a 250 these days. Specially when you are a poor teacher

[Ish]

i weight 125lbs and only get 40 mpg

i ride her spirited.

I am lucky to get 18 MPG on my truck, so I'll take 40 mpg all day any day

[accumack]

Do they still use winter blend gas in MD? When i lived there it cost 3-5 mpg in my 4 cyl chevy s10. When spring came and they switched to summer blend it would go back up.

[greenaero]

Originally Posted by scorch

good suggestions aero.

Today i had a bit of better luck 68mpg. but it isnt very good now that i have 15/38 gearing. and i only filled up because i thought i was running out of gas. THe bike seemed to be have running out of gas, and then i slowed down and it seemed to have fixed it. But it was an odd feeling of the bike struggling as if it didnt have gas.

@scorch, it sounds like you may need to clean your carburetors. When was the last time it was done?

[Ish]

Originally Posted by greenaero

@scorch, it sounds like you may need to clean your carburetors. When was the last time it was done?

Looks like you are the fuel econ expert :P

Does gearing really help?

My gearing is stock at 14 front and 45 rear My freeway RPMS are at 10,000 on top gear keeping up with traffic

Don't mean to hijack the thread, but didn't think gearing would make a diffrence

[n4mwd]

I changed to a 15/45 ratio a while back and there was no noticeable improvement in mpg. I have seen 80 mpg under two conditions. When I was first learning to ride and never went over 45 mph. And when I go on long trips and keep a constant speed less than 60 mph. Around town I get between 60-65 mpg. I weigh 220# and based on what other people are saying, its not that big of a factor for mpg. My weight is probably more of an impact on 0-60 times.

It is my personal unproven belief though that the lower ratio sprockets do make the engine last longer by virtue of it making fewer RPMs.

One thing that will give you more mpg easily is to switch to ethanol free gas. My observations say that it isn't much of an improvement, but its there. Not really worth the extra $1 a gallon IMHO.

Reportedly the new 300 will do over 100 mpg if you ride it like a grandma on Valium and never exceed 40 mph.

[DaBlue1]

Originally Posted by n4mwd

....One thing that will give you more mpg easily is to switch to ethanol free gas. My observations say that it isn't much of an improvement, but its there. Not really worth the extra $1 a gallon IMHO.

A $1 extra a gallon! Wow.
I only pay .10-.20 cents(depending on where I get it) more than regular. In a lot of places around me regular gas is more than the E-free.

[n4mwd]

Originally Posted by DaBlue1

A $1 extra a gallon! Wow.
I only pay .10-.20 cents(depending on where I get it) more than regular. In a lot of places around me regular gas is more than the E-free.

Here in Palm Beach there are a lot of people with boats that have to use ethanol free. So they jack up the price in order to gouge them. Unfortunately, bikers pay the price. I've been told that some of the older Harley's don't run well on E10. The proposal to switch to E15 has nearly caused some bikers to have coronaries.

But for a fact, if I could buy E0 for only 10 cents more a gallon I would.

[greenaero]

Originally Posted by Ish

Looks like you are the fuel econ expert :P

Does gearing really help?

My gearing is stock at 14 front and 45 rear My freeway RPMS are at 10,000 on top gear keeping up with traffic

Don't mean to hijack the thread, but didn't think gearing would make a diffrence

Thanks ! Yes , taller gearing will improve fuel economy (FE) as long you don't try to match the acceleration that you had with your stock gearing. The reduced mechanical friction losses allows the moto to operate more efficiently at the same cruising speeds. If you accelerate just as hard as you did with the stock gearing you will need larger throttle openings and will probably see very small to no gain in FE.

Taller gearing in conjuction with reduced aerodynamic drag is where you see the large gains ( ~ 100% improvement over stock for my streamliner). The 15/33 gearing I'm running on my streamliner is usable only because of the reduction in air drag from my bodywork. It is a complete dog with bodywork removed . Without radical streamlining I've found that 15/37 is about the maximum you should go and still have acceptable acceleration. My other Ninjette ( Silveraero/aerotrunk project) is partially streamlined ( aero windscreen and enclosed front fender) and is running with 15/37 gearing. With the aerotrunk/tail on, I see about a 16-20 % improvement in fuel economy due to the reduced amount of energy needed to overcome air resistance.

[DaBlue1]

Originally Posted by n4mwd

Here in Palm Beach there are a lot of people with boats that have to use ethanol free. So they jack up the price in order to gouge them. Unfortunately, bikers pay the price.

If they got the bucks to own and fill up a boat, that extra $1 probably ain't gonna kill'em in the pockets, like the bikers.

I know I won't use anything else in the bike or lawn equipment if I don't have too.

[n4mwd]

Originally Posted by DaBlue1

If they got the bucks to own and fill up a boat, that extra $1 probably ain't gonna kill'em in the pockets, like the bikers.

I know I won't use anything else in the bike or lawn equipment if I don't have too.

Yeah, I saw a guy at the station put 100 gallons in a speedboat when the price was abut $4.50/gallon. That $450 would have bought a lot of groceries.

Ethanol is disastrous for lawn equipment.

But going Ethanol free is good for the bike. I have already had to replace the hose that goes from the petcock to the carbs because it was decomposing and clogging the carbs.

But back on track, I don't think 63mpg is that unreasonable. You can change the jets and lean up the mix, but you run the risk of burning the pistons if you do. So considering the cost of rebuilding, its not worth it.

[scorch]

Originally Posted by greenaero

@scorch, it sounds like you may need to clean your carburetors. When was the last time it was done?

i might have to clean the carb. But yesterday it did the same but in low speed. I pulled into a gas station, tand the dark thing would not want to start up again.

i had a extra fuel line and removed the old fuel line with the filter and with the new one directly tot he carb, and it started up. and didnt have any more hesitation. The filter must have been dirty.

So far with changing the fuel line i have not computed the mpg. But ill do it tommorow and see how much better it is.

I filled up last friday, and i got 68mpg which is better. but still not that good.

Ill have to look at the carbs, and would not mind doesnt the aero front thing.

[n4mwd]

If you examine the hose and find that it is full of black dust, then the alcohol has eaten it up. I replaced mine with an alcohol resistant hose from advance auto. The problem is that the hoses sold here are US inch sizes and the bike fittings are metric. If you have time, it might be good to order a metric hose online. I think 7mm is what fits it.

[scorch]

fFilled up this morning and i got 78mpg. Much better. But still want better. im riding backroads and not getting up past 60mph much.

I got a touring wind screen and panniers which could decrease in mpg.

[scorch]

Originally Posted by greenaero

Thanks ! Yes , taller gearing will improve fuel economy (FE) as long you don't try to match the acceleration that you had with your stock gearing. The reduced mechanical friction losses allows the moto to operate more efficiently at the same cruising speeds. If you accelerate just as hard as you did with the stock gearing you will need larger throttle openings and will probably see very small to no gain in FE.

Taller gearing in conjuction with reduced aerodynamic drag is where you see the large gains ( ~ 100% improvement over stock for my streamliner). The 15/33 gearing I'm running on my streamliner is usable only because of the reduction in air drag from my bodywork. It is a complete dog with bodywork removed . Without radical streamlining I've found that 15/37 is about the maximum you should go and still have acceptable acceleration. My other Ninjette ( Silveraero/aerotrunk project) is partially streamlined ( aero windscreen and enclosed front fender) and is running with 15/37 gearing. With the aerotrunk/tail on, I see about a 16-20 % improvement in fuel economy due to the reduced amount of energy needed to overcome air resistance.

Aero, where do i begin by making some aero mods to get better mpg?

[agentbad]

Link to original page on YouTube.

[scorch]

i like the aero idea, except i dont like the way it looks. I wish there were better mods to do that would allow it to be more efficient and aerodynamic without it looking like a high school project.

[greenaero]

@scorch, good job getting 78MPG!

The mythbuster segment shows the effectiveness of streamlining but their streamlining is pretty crude and way larger than it needed to be. Too bad they didn't contact me, Alan or Craig to show them what good streamlining looks like.

For the easiest, best bang for the buck effort, read my Aerotrunk thread that I posted in the Cargo section. It covers the construction of the aerotrunk as well as details the improvements to the stock 2005 Ninjette( taller gearing, aero, windscreen, enclosed front fender. If you are not into fabricating your own stuff go with the taller gearing and a taller windscreen. Those improvements with some efficient ridning should easily get past the 80MPG barrier. YMMV

[scorch]

Thanks Aero, i got a touring windscreen at the moment. I will check out the thread about the aero trunk. Im not good at fabricating stuff, but i can give it a try. im leaving on a trip to deals gap this friday, so its going to have to wait until i get back.

Originally Posted by greenaero

@scorch, good job getting 78MPG!

The mythbuster segment shows the effectiveness of streamlining but their streamlining is pretty crude and way larger than it needed to be. Too bad they didn't contact me, Alan or Craig to show them what good streamlining looks like.

For the easiest, best bang for the buck effort, read my Aerotrunk thread that I posted in the Cargo section. It covers the construction of the aerotrunk as well as details the improvements to the stock 2005 Ninjette( taller gearing, aero, windscreen, enclosed front fender. If you are not into fabricating your own stuff go with the taller gearing and a taller windscreen. Those improvements with some efficient ridning should easily get past the 80MPG barrier. YMMV

[scorch]

got 81 mpg today. still trying to improve. i think my carbs might be gunked up. I think my 08 will get better mpg with this gearing as i have gotten 89 in the past on it.

[greenaero]

Good job Ricardo! The taller gearing and clean carbs will help.