Improving mileage?

I get just over 40mpg on my 83 maxim 750. I'd like to improve this, i know easing on the throttle would help a bit. Most of my driving is rural highways (60-80km/h) and freeways (100km/h) not much traffic.

I've done a seafoam treatment to clean the carbs up a bit and i've changed my oil, i've got new plugs and i think my carbs are running a little rich (haven't looked since the seafoam treatment. I also check pressures often. what can i do to my bike to get better mileage? and what kind of mileage can i expect out of this thing... another 10mpg(US) would be nice.

 

You pretty much do the same things that you do in a car to save fuel. Keep tire pressures correct, keep the bike in tune, avoid "jackrabbit" starts, coast (in nuetral) when it's safe and possible and accelerate gently and slowly.

Surprisingly, in my car, holding the throttle position static and staying in the highest possible gear while going up hills is quite a gas saver. Sure you slow down some but you don't increase fuel consumption just to maintain speed. You pick your speed back up on the other side of the hill. It doesn't work on really long uphills though. Not recommended for when you are in any kind of traffic.

 

on the heavy diesel trucks i work on, most of the ECM's can be programmed to have what they call a "soft cruise". its basically a cruise control that allows the speed to drop without the cruise control mashing the throttle to try to keep it right at the set point. just about all large fleets will have us set the trucks up with the soft cruise, because it does save a lot fuel.

 

Lisa:

You are getting 40 which is better than most.
That figure states you are in a relatively good state of tuning.

You aren't going to get much better than that!
That's what most people strive for.
Be happy you don't have Valve or Ring problems that would lower that number considerably.

That's what that engine is supposed to get!
If you need a vehicle more economical ... you'll need a smaller bike!

 

I suppose I should ask, what is a decent mileage that the 83 750xj is capable of?

 

Somebody with that bike will have to answer that.

I have a '83 750 Max. I don't know what it gets for mileage; but it's really very good a delivering "Smileage"!

 

Lisa, If you want to improve on mileage you can do several things, but 1st forget 10 more mpg!

I'd start with colortuning my carb adjustments
followed up by syncing the carbs to a nats - - -
then I'd replace the air filter with a new K&N air filter.
If you dont already have an in-line filter I highly recomend you put one on (use the paper element filter not the stone type)

One last thing is to check to see if you petcock is leaking by, when parked it could be leaking gas into the air filter box or even into the oil or on the ground. If it is leaking I'd fix it 1st.

Again 10+mpg NO WAY! MAYBE 3-4 mpg

Good Luck!

 

why would a maxim not get 50? my 82 750 seca is hitting 49-50mpg just about everytime in fill it up. i know my bike is running rich even, i just havent had the time to perfect the tuning yet (and it runs fine so...), is there something different about the maxim versus seca?

 

find granny or gramps that never goes over the speed limit and follow them
or do it the hard way and diet away twenty pounds, this really works but it's labor intensive

 

Fuel efficiency is a product of Horsepower to Weight Ratio.

Don't carry so much loose change in your pockets! : )

 

Somebody on this site with a fuel injected Seca 750 claimed as high as 55 MPG. I hit 49 MPG with my 900 a couple times, then tweaked the carbs a bit richer, and only got 43 MPG.

The 550's should be getting much better, with lighter weight, efficient chain drive, 6 gears, and a smaller motor.

 

Besides these babys arent no spring chicken any more.
Compression has droped off and then we put windshields on and cruise pegs......ETC.

 

for racing MX or flattrack on a quad, the general rule is:
gain 1 HP = lose 7 lbs.

 

I drive an '82 650 Maxim to work and back every day and I average 50 MPG.

I've found that I get the best mileage at around 55 MPH. Remeber the 55 MPH speed limit when these bikes were made? That speed was picked because it was near the most efficient speed. As you increase speed, the wind drag goes up and mileage goes down. Slower than that and you're lugging the engine in top gear.

By the way, my bike has 32,000 miles on it, a windshield, a trunk, and I weigh 190 lbs.

For a 26 year old bike with good power to get 50 MPG on 87 octance gas is fantistic!

 

My 83 750 Midnight Maxim gets 40 to 43 mpg. I weigh in at a fluffy 290. hehe. I feel anything over 40 mpg to be great since my best cage gets 32mpg and my truck gets 17.

 

My '80 XJ650 Maxim w/windshield and my 250 gets right at 45mpg. Most of it is on the highway and the cagers are pushing 80+ until I get off the HOV lane. It would probably get close to 50 if I was able to hold the speed down.

 

ok, well for a 1000 dollar bike I guess I didn't do too bad...

for compression I get 160 on all the cylinders.

I don't have a windshield but I've been planning on getting a small one (i'm wearing 2 pairs of pants my leather jacket with the liner and a full face helmet and i'm STILL freezing on the bike. must be me cause i see plenty of squids out there.

 

lol i love florida

 

So What is the fule tank capacity for 82 550 Maxim ???

 

I get about 43 mpg on my 82 Maxim 750. That's straight from the PO with just an oil change. I ride mostly secondary roads at about 50-55mph.

mikeg

 

My 750 maxim gets a steady 44 mpg i keep speed down cruise around 45 -55 mph most of the time use middle grade gas



82 maxim 21k miles daily rider

 

I get on an average of 45 MPG on my XJ700...and have seen tanks get 55 mpg....I always burn 93 octane...but found that some gas brands are better than others....I avoid using the "Green" 10% ethanol in my bike...I found it doesn't run as smooth and get as good mileage

 

OH, I weigh about 150 pounds. I guess that can make a difference

 

i have an 83 750 midnight and i get close to 45-48 mog each tank, keep it at the speed limit, and a near perfect tune will go a long ways, also if you add a windshield your fuel mileage will drop off considerably. My 78 cx500 gets over 50 mpg, but before i put the windshield on i was getting over 60.

 

Sounds like you guys are doing good, I average about 50 mpg on my 400 twin....

 

Second that!
40-45 is about what I get also. Honestly it's better than my CB750 Supersport that I had. It was tuned to perform with a 4 into 1 canister, no baffle and 2 size up main and pilot jets. It got around 35mpg or so, but it was fun to ride too!

 

Man, I heard that. My 550 is getting high 40's on the commute, I pretty much HAVE to run between 75-85 most of the way into the city or I will get RUN OVER. If I could just run at a leisurely 70 I'm sure the mileage would be better. That being said, the XJ will run 80 all day and it does get better mileage than my Wabbit.

 

3.4 US Gallons, of which 1.0 gallon is "reserve." This according to the factory service manual. (Seca is 4.2)

 

Wow, so I am getting lousy mileage at 34. So I guess a carb synch is in order and I don't know if it is running rich. I guess I should check the plugs, man I was just happy to get it running. How depressing! One other thing what is the oil level needed? When its sitting and off oil level is above line on glass viewer. On and running it is low? So where is it suppose to be and when do I read it?

 

wbaize
you check your oil when on the center stand.
The oil level should be in the to 1/2 of the sight glass. If it goes higher it could mean that you have a faulty petcock leaking fuel into your oil when the bike is sitting.

Also you may need more than just a sync, I recomend that you colortune the carbs so that you get the fuel mixture just right, then sync, then colortune again and sync again.
Valve adjustment may be needed but I'd start with the easy stuff 1st.

Good Luck

 

You read the oil on the main stand. Either cold, or 10 min. after it ran to allow drain-back. A trick I read in these excellent forums, is to fill until you just have a tiny air bubble left visible. Now you can check easily if your carbs flood out your crank case- - that little bubble would disappear.

My 750 was getting 32 - 38 MPG and never seemed powerful. It had 118 jets, and really needed 122 - 124 ?? because it has pods and a 4 - 1 pipe.
I opened the carbs yesterday to install some 120 jets, and to clean - check, and I fould a diaphram folded over a little on one of the carbs!!
That would basically de-activate the slider piston, so I was running on 3 1/2 cylinders this whole time. How could I make such a mistake!

When you put your carb hat on, you can slide it around and check that the diaphram is totally seated. I bet a few others out there are driving around with this invisible problem.

 

you know, the only folks that dont make mistakes are those that dont do anything!!!