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MPG
- Thread starter Joshwuh
- Start date
Here is a question? How is your Air Mix screw set?
Factory setting 1.5 turns? = greater Distance per Gallon or Liter?
Generally accepted 3.5 turns?
I am ass umming that my Carbs were set to 3.0 turns, and I have been getting 42 miles per gallon. at 112 miles the reserve kicks starts to let me know its time to look for a gas station. if you remember. this thread is making a correlation between our wt, Ht, and what everelse, so I am just wondering. Today I have set it to 1.5 turns, just to see how that works.
MPG results, day one 73.9 Miles/2.018gallons=36.62MPG with 2ppl on it, pushing 440lbs, I will add-on tomorrows results (pilot screw was turned down to 1.5 turns.) previous mpg was 42mpg at 3.0turns.) my brakes took a beating yesterday.
Factory setting 1.5 turns? = greater Distance per Gallon or Liter?
Generally accepted 3.5 turns?
I am ass umming that my Carbs were set to 3.0 turns, and I have been getting 42 miles per gallon. at 112 miles the reserve kicks starts to let me know its time to look for a gas station. if you remember. this thread is making a correlation between our wt, Ht, and what everelse, so I am just wondering. Today I have set it to 1.5 turns, just to see how that works.
MPG results, day one 73.9 Miles/2.018gallons=36.62MPG with 2ppl on it, pushing 440lbs, I will add-on tomorrows results (pilot screw was turned down to 1.5 turns.) previous mpg was 42mpg at 3.0turns.) my brakes took a beating yesterday.
Last edited:
NRA-
XS400 Member
Haven't posted much, but here we go again. First hope to turn you on to a new site for figuring your mileage easily on the go. It's fuelly.com You can use your cell phone to text info, or go online, after signing in. You text something like this " m 111.07 3.5399 1.855 anything after gallons will be kept as text like Sunoco, 8th street 87 octane
For me it means: m for motorcycle, 111.07 for Miles, 3.5399 for price, 1.855 for Gallons. You are texted back something like Fuelly added, mileage this trip, average mileage to date. Online you can do other stuff.
Ok, my mileage, have gotten as low as in the 4x. mpg after having used the reserve tank. Got to rebuild the pet cock one of these days. mostly seem to get around 54 mpg, my best MPG have been something like 63 mpg, and the absolute best was recently 65.15 mpg. Then tried a higher octane which brought me down to 54.xx.
I haven't done anything special to get better mileage. Just change the spark plugs once in a while. I'm not much of a gear head. Oh, I didn't baby to to get the best mileage, some in town ridding, outside of that mostly ride at 40 to 60 mph, sixty mph infrequently. I weigh 175, am 5'9". Have saddle bags with about 20# in them. Hope to see you at fuelly.com. You can also compare your mileage to others with the same ride.
For me it means: m for motorcycle, 111.07 for Miles, 3.5399 for price, 1.855 for Gallons. You are texted back something like Fuelly added, mileage this trip, average mileage to date. Online you can do other stuff.
Ok, my mileage, have gotten as low as in the 4x. mpg after having used the reserve tank. Got to rebuild the pet cock one of these days. mostly seem to get around 54 mpg, my best MPG have been something like 63 mpg, and the absolute best was recently 65.15 mpg. Then tried a higher octane which brought me down to 54.xx.
I haven't done anything special to get better mileage. Just change the spark plugs once in a while. I'm not much of a gear head. Oh, I didn't baby to to get the best mileage, some in town ridding, outside of that mostly ride at 40 to 60 mph, sixty mph infrequently. I weigh 175, am 5'9". Have saddle bags with about 20# in them. Hope to see you at fuelly.com. You can also compare your mileage to others with the same ride.
"The metric system is the tool of the devil! My car gets 40 rods to the hogshead and that's the way I likes it."
- Abraham Simpson
- Abraham Simpson
63-Coupe
XS400 Addict
What's that in Celsius??
NRA-
XS400 Member
Should have mentioned, fuelly.com lets you choose between metric and good old USA calibrations. Hope that works for you.
83xs400
XS400 Enthusiast
i get 5.7 L per 100 or 49 mpg
straight pipes, K & N air filter and +1 sprocket in the front
and i weigh so 235 so id say thats pretty good
straight pipes, K & N air filter and +1 sprocket in the front
and i weigh so 235 so id say thats pretty good
"Good old USA Calibrations"? What is good about outdated measurements designed to cheat the rest of the world? And when will Amerikan's realize that their country switched to the Metric system in 1975? At least Amerika has something in common with Liberia...
My Maxim has averaged 5.19 L/100 km in the past 10,000 km. Though it has been getting closer to 5.5 L/100 km the past month or so as I've been riding at higher speeds.
4.92 L/ 100 km here 
guess I'm not as sporty of a rider as I thought I was, or my measurements are off (could be, only one 12.6 liter interval measured)
thats 47.8 mpg
guess I'm not as sporty of a rider as I thought I was, or my measurements are off (could be, only one 12.6 liter interval measured)thats 47.8 mpg
When expressed as litres per 100 km Abraham was right. I get between 21 and 22 kms per litre.
So at 2 turns out,
previous day7/6 39.68 gpm
Yesterday was 37.5 gpm 7/11/13 filled it up this morning.
So far this doesn't' seem to be the variable that creates better gas mileage.
previous day7/6 39.68 gpm
Yesterday was 37.5 gpm 7/11/13 filled it up this morning.
So far this doesn't' seem to be the variable that creates better gas mileage.
Too lean a mixture will cause the engine to run hot and make less power. Power = Efficiency.
devdg
XS400 Enthusiast
so by reading this I need rebuilt carbs I get 130km to a tank and I figured that was low
where did you get that Idea? Carb rebuild? If your having some motivational disorders,(your bike not wanting to move) and you have not cleaned your carbs, you might need to do some double checking, followed by some triple cleaning. Our carbs are very picky about being clean. As you look up various symptoms here on this website, or even google, you will see there is only a few things that you might need to get. all depending on what you find. Some people switch to Pods, and that seems to be science that I have avoided, I am convinced that there is mileage per gal/km by adjustments that we make by tuning things up. Our websites recommendation when you put the pilot idle screw together, has been 3 turns. When the bikes left Japan to america, for EPA reasons the screws were set at 1.5 turns and then plugged with a hard plug to pull out. So I am at 2 screws out, and I am getting about 40, where when I started the experiment at 3 turns, I was getting 42. Last year I did valve clearance, Next time when I take the tank off, I will try 2.5 turns. I have never done a compression check, but it drives great, Great acceleration. I am running out of variables that give some 60 MPG. I will try the fuelly.com
Randomly adjusting the pilot screws is not the best way to go about this. The manual suggests an initial setting that will (probably) get the bike running. After that, the pilot screws should be adjusted for the correct mixture. Many use Colortune spark plugs so they can see the combustion process. I use a vacuum gauge and the tach to adjust for strongest idle and then adjust slightly richer. I prefer slightly rich as the engine warms up easier, will idle cooler (important when stuck in traffic) and will backfire less on deceleration.
Once the pilot screws are adjust correctly for the idle mixture, don't forget to sync the carbs. If it takes a lot (1/4 turn) to get them in sync, go back and recheck the idle mixture. If you have to adjust the mixture, check the sync again when done. Back and forth until it is as close to perfect as you can get it. Be sure to not overheat the bike by idling too long, or loading it up with too rich a mixture. Take it for a quick rip around the block every time you finish making an adjustment.
Once the pilot screws are adjust correctly for the idle mixture, don't forget to sync the carbs. If it takes a lot (1/4 turn) to get them in sync, go back and recheck the idle mixture. If you have to adjust the mixture, check the sync again when done. Back and forth until it is as close to perfect as you can get it. Be sure to not overheat the bike by idling too long, or loading it up with too rich a mixture. Take it for a quick rip around the block every time you finish making an adjustment.
Maybe you need to stop red-lining it every time you accelerate up a long, steep hill
Sorry, wish I could offer some actual advice. Carb tinkering is a science I have been lucky enough to avoid entirely, so far.
I could go on a diet 
210lbs
Thanks Dave,
210lbs
Thanks Dave,
devdg
XS400 Enthusiast
Maybe you need to stop red-lining it every time you accelerate up a long, steep hill
yeah and where would one find a hill in saskatchewan.
I have cleaned the carbs and run firm but not hard wire into the ports and jets to make sure they are cleaned out.
Does anyone know where I can get a proper book for the bike I have a haynes but it does not cover the XS400J and it talks about position clips on the needle valve. I'm new to MC carbs, I have rebuilt a few carters and holleys.
Nut Mountain?
As to a book on the 400 Maxim, the only one I have seen is the shop manual for the 400 Seca which is on the Forum for download (2nd item on GARAGE). The engines and most of the maintenance and overhaul procedures are the same as for the Maxim.
According to veterans of the Carb Wars on here, breakthroughs usually occur after the 3rd or 4th attack - rarely after only one. Wish I could help more...
devdg
XS400 Enthusiast
i ride t\it to and from work each morning less then a 3 k each way so the fuel is not a big thing i did notice it when i went on a trip to the city so i suspect i will have to try the boiling vinegar.
