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Increasing mileage

4K views 39 replies 6 participants last post by  AlbertaBeef 
#1 ·
I am having horrible mileage on my bike. I get 200 km, which is 125 miles out of a tank on the highway, doing 110 km/hr (70 m/h). IS this normal for this bike? I bought it last year, and was surprised at how low of a range I get on it. It has been re-jetted and vance & hines pipes put on by a dealership. It is carbureted, not EFI.

would a K&N fileter and new intake help?
would I need to get it re-tuned?
I run premium fuel, and try to avoid heavy throttle.
I would love a taller gear.

I would love some suggestions on this.
 
#2 ·
That is about what I get on mine with FI. That is 3 gallons and where the low fuel light comes on. Mine has Vance and Hines pipes and I have the original pipes. I did not see much if any difference between the original and the V&H pipes. An indicated 70 is about 65 for my bike. I did get 62.5 miles per gallon once. I rode with a couple of friends and we drove about 65 on a short trip. I went 125 miles and used 2 gallons, but the last gallon (3rd) always falls really fast. I very seldom push the last gallon in the tank since the lower fuel level is not good for the fuel pump. (injected)

So my typical average is about 38 - 42 MPG.
 
#3 · (Edited)
I have a 98 1500 Classic...with a carb..

Only performance upgrade is V&H Pipes and jetting --- and yeah....about 120 - 125 miles between fillups.

That's about 75% freeway and 25% riding around on surface streets...

I'd be interested in what others say about upgrades..

I like to think I pay for the smiles, not for the miles....just to put a positive spin on it...
 
#4 ·
I run premium fuel, and try to avoid heavy throttle.

try to use regular octane and not premium, because your 1500 is not over 10:1 compression and under 10:1 using premium fuel the combustion will not get hot enough to burn all the additives in the premium and those unburnt carbons will cause cylinder piston buildup and also a lot of soot in the pipes, those high compression motors over 10:1 need premium to prevent pre-ignition from the heat in high compression, but your 1500 only needs 87 octane
 
#5 ·
on your 200 km run, do you know how many litres the bike used? was 200 km a full tank to empty?
 
#8 ·
you say your bike was re-jetted, was that done before you bought the bike or after
 
#10 ·
does the bike have now a stock intake or aftermarket intake, i mean air intake
 
#11 ·
a couple things, when changing the stock pipes to V&H pipes, and keeping the stock air intake, most mechanics will just adjust the pilot jet mixture screw, they would open it up counter clockwise another full turn from the stock position, and not change the stock pilot jet or the stock main jet but leave those 2 jets stock. When changing the stock air intake to aftermarket air intake, is when a mechanic will increase the pilot jet (PJ) and the main jet (MJ) sizes. Being that the Honda dealer only changed the pipes to V&H, and if the PJ was increased, and/or the pilot jet mixture screw opened up too much, that could be the reason why the bike is using more fuel, so yes the culprit for your poor gas mileage could be the incorrect adjustments made to the carb, the fix to it would be to find out what the stock size is for the 1500 PJ and MJ and then find out what PJ and MJ sizes are in the carb now and what setting is the pilot jet mixture screw at, if the dealer did not change the PJ and MJ but left them stock, then the culprit is the pilot jet mixture screw setting
 
#15 ·
ya a K&N filter could benefit, I mean if you're carb is putting in more fuel then required for your present stock intake and stock paper filter then changing out the paper filter to a K&N could let thru more air and correct the suspected overly rich fuel mixture. The new K&N could fix the poor gas mileage when you're only using 1/4 throttle on the highway going 110 kmph, but if you open up the throttle more beyond that the inner workings of the carb is going to draw more fuel thru the Main Jet (MJ), and that might be a problem because your present MJ size is suspected by us to be the stock size, not sure the stock size but I will take a wild guess at it and say your stock MJ size on your bike is a 138. So when you open up the throttle then a 138MJ is going to be too lean a fuel mixture for combustion and things could get very hot inside those 2 combustion chambers, but I don't know exactly and the only way to know for sure is to have the bike with a K&N filter on your stock airbox be on a dyno with a gas analyzer to measure fuel mixture ratio when the bike is on full throttle position, but dyno's are not economical when all you want to do is increase your mpg a bit more from your current 12.5 km per litre, (200 km from your 16 litre tank), 12.5 is too low and you should be at least a minimum of 15 km per litre
 
#16 · (Edited)
the term 'rejetted or rejet' refers to changing out the pilot jet and/or main jet, and since we don't know what size your carb jets are, we don't know if the Dealer mechanic just adjusted the mixture screw or changed the stock jet sizes to something else, we don't know and we're just flying blind at this point. so you will need to decide if you want to dig into this with some of your time and some metric tools and remove the carb and investigate what is in there, including checking to see if the needle is still stock or did they install an aftermarket needle, or do you want to live with your 12.5 km per litre setup, or do you want to buy a K&N air filter and try that, which you'll have to judge by the seat of your pants and intuition on that to determine if using a K&N increases your km/litre range yet the bike does not get too hot at 1/2 throttle position and you'll need your intuition on this to judge this, also by the bike hesitation or surging, all these are signs carb modifiers use to judge if carb is too lean or too rich, I hate running blind on things like this but I guess the only way to really know is do a dyno or else return to that Dealer you bought the bike from and find out exactly what was changed inside the carb, or else investigate the carb jets and needle yourself to know for sure. got any tools? is bike in a garage?
 
#18 ·
what if he were to inquire at the Dealer where he bought the bike what information he can gather on what was done to the carb, it would also be nice to have the maintenance and modification records on the bike if the Dealer has them
 
#20 ·
I have had more bad information from dealers than I care to list. The ones I dealt with had mostly young guys fresh out of school with limited experience with carbs, or anything for that matter. One of them, a pimple-faced kid of about 21, tried to tell me he was certain that an electrical problem I had was the kill switch shorting out without even looking at the bike. (It wasn't, it turned out to be a wire on the fuel pump had rubbed against the frame and shorted out).

The dealership where I live now sells mostly 4 wheeler ATVs, jet skis and dirt bikes. I found an old guy who was a Kaw and other metric brands bike mechanic in the 70s, 80s and into the late 90s who works out of his own garage who does a much better job.
 
#19 ·
I bought the bike used in a private sale last April. I bought it with these mods done. I have the receipt for the jetting, and was given the old jets. I no longer have them.
While it is true I can't do anything until spring to the bike, I have found this trhead very valuable on possible issues that I can investigate. I can source and purchase a new intake and filter, and have them ready for when I have access to the bike again.

While the mileage has been poor, so has the power. Perhaps more breathing capability will increase that too.

I really appreciate all of the comments so far, thank you. Would a new intake be recommended, or is the stock circle intake adequate?
 
#21 ·
I am not a big fan of partially modding a bike. These machines are set up from the factory to reach the optimum balance between performance and efficiency. They are set up on the lean side to meet environmental standards, so the fuel, air and exhaust are all fairly restrictive on these bikes. When you alter any one of the three components of combustion, you are upsetting the balance. I know lots of guys will tell you that if you just change the pipes, you won't have to rejet. Maybe, maybe not. It depends an awful lot on the bike, where you live, how you ride, and more importantly what pipes you put on the bike- length, diameter, head pipe curvature, baffled or not. Exhaust controls the volume of air and the velocity by which it leaves the header. It is often assumed that more volume = better performance, but if the velocity of the exhaust is diminished, it is not moving exhaust out fast enough. It may, however, move more air volume than the factory exhaust with the catalytic converter did. Therefore, you are risking making an already leanish bike even leaner.

I would do air, pipes and jets all at once and then be able to correctly find the "sweet spot" balance of air, gas and exhaust. If the PO changed the pipes and the jets but not the air, and it still has the stock paper filament in it, it may be running too rich. That's why Mr Fair wanted to you to look at the plugs. Black and sooty= too rich. White or ashy grey= too lean. The color of coffee with cream in it is about right.

You can get a K&N hi-flow filter and keep the same dog bowls if you choose. I did that for years until I bought a Baron's Big Air kit that bolts right to the carb.
 
#22 ·
Wow, thanks Patrick! I have never had an opportunity to be mechanically involved, but am determined to learn and understand my bike. I thought he meant spark plugs, but didn't really see the context. I do now, thanks for the clarification. In April or May I will go pick up the bike from storage and get it ready for riding! I now have goals and a course of action. I was getting ready to sell the bike, but If this will get me the results I am looking for... great!!!
 
#24 ·
AlbertaBeef, Would a new intake be recommended, or is the stock circle intake adequate?

ok good question, about your 2003 1500, the model for your bike is VN1500E6
the factory stock MJ and PJ for your bike when new was,
138 MJ
45 PJ
Pilot mixture screw aluminum plug installed

When you bought the bike last april 2016, the previous owner rejetted the carb with V&H pipes and kept the airbox factory stock and you have the jetting receipt.
You are experiencing poor gas mileage of 12.5 km per litre which is low, with 15 km / litre being minimum you should be getting.
You also mention that your bike is having poor power, which corresponds to the low km/litre number, the culprit looks and appears to be the bike is too rich, which is causing the poor power and poor mpg.
rich = too much fuel to the amount of air intake

you asked if breathing more air would help and the answer is yes, if you leave the carb as it is now, letting the intake become less restrictive would help yes, but here are some comments I have doing that.

If you want to install an aftermarket intake (less restrictive), the gas tank has to come off and the carb removed and the cross-over tube from the left-side filter to right-side intake has to be cut out of there and removed. With an aftermarket intake, the carb jetting needs to be richened up, and given that even if the MJ and PJ in there now is perfect for a new aftermarket intake, you will need to remove the carb anyways to find out what the jetting currently is, unless that receipt from the previous owner has information on the jet sizes installed.

If you want to keep the intake as it currently is, and since the bike is running rich, to fix the poor mileage you will need to find out what size jets were installed and how many turns the pilot mixture screw was adjusted which means you will need to remove the carb anyways to find out.

Or you can decide to live with your present setup as is now, one thing I recommend is to use regular 87 octane fuel and not premium. You could also try a K&N filter and see how your power and mileage work out. The only risk to that would be you find out that with a new K&N you still have poor power and poor mileage and the expense of the K&N was of no help, but it might help, the only way to know is to try one. A new aftermarket air intake is also costly, and there is some work involved in that to install it and also carb work to get the jetting right.
 
#32 ·
You do not have to remove the crossover tube and bolt the air intake onto the carb. When I got my pipes and jets, I bought a K&N Hi-flow replacement filter and ran it in the stock dog bowl for 8 years and it worked just fine. I only ran a Baron's Big Air kit because I liked the look better.
 
#25 ·
Thank you Btom for the detailed response. I did not realize it was such a big job. I am not set up to do mechanical work, so it must be farmed out. I have to consider all costs, as I am considering getting a different bike, and don't want to be throwing good money out the door. I am guessing this would be close to a thousand dollars to have done. I just spent close to that on new back tire and bearings in the fall. It might be worth it though, if it gives me the mileage I need. The closest town to me is 210 away, and if I go under the limit all the way, I can make it on fumes. If I can increase the range even to 250, I could breath easier. No pun intended.

You all have given me much to consider, thank you for all the info.
 
#26 ·
By the way Alberta, there is something else that we don't know at this point, and that is the needle, which is at the top of the carb, with the jets and mixture screw being at the bottom of the carb, but we don't know if the previous owners installed an aftermarket needle in the top, like maybe a Dynojet needle that has notches on it with an e-clip to set needle height, or if the needle in there now is still factory stock, that part is also an unknown, maybe the receipt you have has information on any new needle installed, if the receipt says nothing about a needle, we can assume that the needle in there now is still the stock one, but there again, another unknown, if you don't mind my giving you a recommendation, then I would try a new K&N filter first, yes they are not cheap but that would be a whole lot easier and less costly then going the new aftermarket air intake route with carb work.
 
#27 ·
ok I just read your post #25, and you are considering a different bike, and don't want to be throwing good money out the door, which to me is a good thought, because your bike is a 2003, and yes it's a good bike and still runs but it's still a 2003 and being upgrading to a new air intake and carb work costs from another mechanic is an option, your bike is still a 2003, I personally wouldn't put that much money into a 2003
 
#28 ·
by the way, even if you invest more money into your 2003, consider the day you decide to sell it, I doubt very much that a new owner will pay for any work you have put into your bike, so consider anything you spend on it now will just be for your own personal pleasure that you will not be reimbursed for by someone else
 
#30 ·
This is exactly the dilemma I am facing. While I could easily make the payments on a new bike, my wife is insistent that we pay cash, and not go into debt. With the economy the way it is in Alberta, we don't want to find ourselves in a bad place tomorrow. On the same note, we can probably get better deals on newer used bikes.

I am sure I could get $4000 (or close to it) out of the bike, which is what I paid for it. I really like the bike though, it has a very low center of gravity, and is very stable! It corrects itself when there are ruts in the road or in a crosswind. Heavy and low has saved me in the past.
 
#29 ·
If I can increase the range even to 250, I could breath easier

you are getting 200 km now on a full tank, and with any new air intake and carb work you could probably expect to get 16 km/litre, which would take you 256 km full tank bone dry best case scenario, 240 most likely is what you would get realistically
 
#31 ·
if I can add my opinion on this and not get flamed for it, I would say, don't invest a single penny more into it, ride it as is, have fun with it and forget any new air intake and or K&N filter, and listen to your wife, cause ya I believe wives speak wisdom, ok you guys can flame me now.
 
#34 ·
I think you're confusing him with all that unnecessary incorrect info
 
#37 ·
cross-over tube, you talking left side when I'm talking right side, full mod of air jets & pipes, suggesting plug chop reads, bad dealer mechanic experience, doing a full mod of air jets and pipes when the bike is a 2003, cash register rings on that one
 
#38 ·
Look, I don't know you, but I'm assuming you're probably a nice guy. I asked you to point out where I dispensed incorrect information. You so far have only offered the opinion that you don't agree with my assessment, but you did not refute a single thing I said as being incorrect.

You seem concerned that I was advising the OP to spend a lot of money. To the contrary, I urged him to invest in a high flow filter for about 60 bucks to keep the factory air setup and save the hassle of cutting out the crossover tube and the expense of buying a new air kit. I mentioned that I did it but only because I like the look.

I do, however, think it is foolish to disrupt the balance of air fuel and exhaust that is set at the factory by changing only one or two of the three. I can show you lots of guys who today have fouled plugs and valves from running too rich or blued pipes and engines wearing out much too fast because they're too lean, all because they wanted to save a few bucks and only do one or two of the three mods. They essentially wind up with a bike that makes more noise but is shortening the life of the bike by years. However, since the OP has a bike that has aftermarket pipes and jets but not air, it is likely an easy an inexpensive fix.

And then you said this:

I would say, don't invest a single penny more into it, ride it as is, have fun with it and forget any new air intake and or K&N filter, and listen to your wife, cause ya I believe wives speak wisdom, ok you guys can flame me now.
No flaming, but seriously? That is some terrible advice. There is no reason for these bikes to not be running at top form, and even though it is a 2003, it can easily run for 20 or 25 years and over a hundred thousand miles if well maintained and properly set up. Running a $4000.00 motorcycle that isn't running great is just not that smart nor necessary, especially since it won't take much time or money to make it right. That is all I'm saying on the matter; I'm not interested in a pissing match. I hope the OP gets his stuff straightened out, because that bike is a great bike and should last him a good long while.
 
#39 ·
And by the way, no one said anything about chop-plug reading. Both I and Mr Fair suggested looking at the plugs, because inspecting your spark plugs is the first thing to look at when trying to determine if the engine may be running rich or lean. Maybe the problem is reading comprehension on your end.
 
#40 ·
You have all given me great advice, which is exactly what I came here for. When I pull the bike out of storage, I will check the plugs and probably replace them no matter what they look like, and throw in a K&N or other high flow filter. I will also switch to regular gasoline and see how that changes the performance and mileage. I don't want to put any more money than I have to into it, and I think I will avoid the dyno and carb adjustments, at least for the time being. I think it may be diminishing returns after that.
 
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