Mileage. A poll.

I went for a run on mine a couple of weeks ago (for the first time since getting the bike), and went 111 miles and used 7.5 litres, which equates to 1.9 Gallons (English, not American), it did the same on the return journey too, which comes out to 56 to the gallon and that was 2 up too, in both directions. I'm happy with that.

Pete

 

Simply, I have 2.5 gallon tank. at 100 miles no more than 103 I am on the reserve. This seems to hold true for me no matter if I am running highway speeds 55-70 MPH or just going 25-45 MPH. The one time I did run her completely dry and I was coasting in to a gas station I was at 125 miles...

 

I believe a stock 82 650 Maxim should have a 3.4 gallon tank (including reserve). You would go about 40-50 miles further before hitting reserve. I thought you might find this info useful since I saw your other thread about wanting a 750 tank for the larger size.

 

You can only get about 2.5 gallons out of a 650 tank before you hit reserve, which is usually around 100 miles. I speak from lots of experience. A 750 tank does help a lot, especially if you commute or ride long distances with others. I love my 750 tank on my 650!

 

according to the Haynes guide the tank for an 82 JX650- G, H LN & J 13.0 litre 3.4/2.9 us/imp gal But I know my tank holds 2.5 gallons of gas. So yeah I am on the lookout for a 750 tank!

 

Well, I might be "cheating" on the reserve issue. Since I run mine on prime I don't fill up until I hit 140 miles. The most I've put in at once was 3.1 gallons, and that was without running it out/dry.
And yeah, I'll rebuild the petcock someday....

 

I drive a 82 maxum 550 50-60 miles a day 40 back wood highways the other in town rain or shine. Excellerate to 90mph befor shifting out of third and still get 56mpg consistantly. Heres a strange thaught that excellerating slowly hurts gas milage by making a engine work at higher rpms for longer times. so speed up faster :lol:

 

I've actually wondered that myself....that under acceleration the fuel consumption per second between half and full throttle is not as much as the time difference between the two. So that if you get to cruising speed quickly you spend more time and miles at the lower consumption rate.

However, this is a question for experiment, not speculation.

Anyone have one of those special fuel mileage calculators that you can attach to your car??? Or SQLGuy can put one on his bike!!

 

Well for me it works on my caddy. speed up to over drive speeds saves me 5 mpg on the same 50-60 mile trip to work. So it couldent hurt to try. :lol:

 

Long ago I read that you get to your cruise speed moderately quickly - not full bore, not slow. but (in a car) the max fuel economy is at 40-45 MPH.

A bike is less efficient and needs 50 to get the best economy.
Fuel injection helps. My FJR gets 70 MPG at 45.

 

I get 42-45 mpg on my '82 650. I ride around 95 miles round trip to work everyday, all highway and rarely under 75 mph.

 

I was commuting on my '85 xj700 for a while and I found it only got 35 to 40 mpg right at 75 mph. I think the tuning could have been a lot better though, so that obviously makes a difference.

 

I had the unique opportunity to have to drive about 125 miles on the freeway the other day, right after I got some gas, mostly at 75 or so...I got the best mileage I have ever gotten except once, 43.7 mpg. That even included some normal stop-n-go.

I'm still trying to figure out how I got 53 that one time. Went up to Ramona and only used a gallon of gas? Did that same trip later but no dice.

 

Came across this poll in your sig day7a1, thought I'd give my two cents. I get on average 45-50 mpg on my 83 xj750mk. Thats mostly running secondary roads. Ive gotten close to 60 mpg once and that was on a 150 mile ride with my dad and his buddy putting around on their "hogs". I swear they ride like old people "make whoopie". Or maybe thats all the faster their noisemakers could go. Shouldve shown em what a REAL bike can do!!!

 

New to the whole XJ world. Thank god for this site! I bought my 1981 XJ550 about a month ago and the p.o. had replaced the rear brake and cleaned/bench synched the carbs(my XJ was the 5th bike in his garage and he obviously loves to work on things-Star Wars fan who builds giant model ships, so I feel good about the carb job he did). The ppo had adjusted the valves now about 700 miles back. The bike was in great shape for a 1981, but it still needed/needs more TLC. The po was running regular gas and hadn't cleaned the bike real well.

My gas mileage was 39mpg first time (60%highway/40% low speed). I changed the oil/filter with 20w/50, and found the tires to be 18/25psi rear/front, so I took them to 31/29. Then I filled up with 91octane & a little bit of Sea Foam and my next reading was 49mpg (same hwy/S&G ratio). Third test yet to come! I am extremely impressed with the power and mileage so far. Must be a YICS thing

 

I am getting 45 right now.

 

I rode several 100 mile trips a week for the last 3 months and kept a chart of my running average. I drove the same route every time (all freeway and I always ride the speed limit) I live 100 miles from my work. The results were astoundingly tight at 48.3 mpg and all points were in the 1 standard deviation limit. No trends, no shifts and no outlying points. If I could have gotten my chemistry analyzers to run that tight I would be a clinical scientist god! 48.3 mpg on my 83 XJ750 and I can say that with complete statistical certainty.

 

Amazing because gas pumps are allowed to be 5% out within the law, and the Ethanol varies between 5.9% and 10% with some stations being caught higher, occasionally.

 

That would account for the data points all being within 1SD but scattered on both sides of the mean. I also always stop at the same gas station before each trip. When I get her rebuilt I will throw in more varied driving conditions and see how that affects the data and my mileage. I also want to see what my carb cleaning and tuneup does to the mileage. All in all I would hypotiesize that the linearity is due to the great engineering of these motors. I was going to do this post myself after I had a larger data set but someone beat me to it.

 

Honestly in the 15 years I have owned my XJ I dont think I have ever checked the mileage. That will give me something to do this weekend

 

Keeping accurate track of your mileage under similar conditions is a great way to detect motorcycle problems before they are noticable in any other way. That is why we apply statistical control data when operating medical laboratory equipment. In both cases (lab equipment and motorcycle performance) lives are on the line.

 

Gee, I have never ridden sedate long enough on my turbo to get over 20mpg. At 18psi, it's burning old plants and animals at an alarming rate.....but it's ohh so fun!!

jeff

 

I get roughly 42mpg when I rode solo, 48 when my wife is on the back. Riding relatively sedately makes up for the extra 'cargo'.

 

I have three XJs.

The 82 650 Maxim has the YICS plugged and it gets a max of 53 MPG.

The 86 XJ700 Maxim-X has a high of 49 MPG

The 82 XJ1100 has a Dynojet stage 1 kit and gets a max of 36. I need to finish rebuilding a second carb bank and see what I get with properly adjusted stock carbs.

 

I have been riding country , windy 2 lane roads with no stops for a 100 miles rolling throttlein and out of corners all in 5 th gear and would guess on these mountain roads its about 48mpg at a constant 55 mph speed on my 82 xj 750 rj bone stock except the k/n air filter in stock box . I am 6'2" at about 250 but generally dont carry any other cargo .Well except my over sized self that is