What kind of mileage do ya get?

Thanks for the info Hoss.
Sounds like a project for next winter. I'll have to study up on how the different gear ratios effect the rpms. I want to keep acceptable performance but would like a little better fuel mileage and don't want to shift gears so often in town. I think ultimately I would like to have gearing that would give me somewhere around 4000rpm while doing 75mph (right now it's around 5500rpm).
 
Just did some number crunching regarding tires sizes and RPM in 6th gear:

Stock size 160/80-15:

50mph - 3600
60mph - 4300
65mph - 4700
70mph - 5000
75mph - 5400
85mph - 6000

170/80-15:

50mph - 3500
60mph - 4200
65mph - 4500
70mph - 4900
75mph - 5200
85mph - 5900

These seem to jive pretty well with what the majority of members are reporting... However based on gds's numbers from his bike with a reported 170/80-15:

From post #39:
50mph - 4100
60mph - 4700
70mph - 5300
From post #53:
80mph - 6000

These numbers are pretty similar to a 170/65 (I don't know if they even make sucha thing...) or a 150/70. Not sure what's going on here still... unless he's running a really flat tire!! :laughing7:
 
gds said:
Thanks for the info Hoss.
Sounds like a project for next winter. I'll have to study up on how the different gear ratios effect the rpms. I want to keep acceptable performance but would like a little better fuel mileage and don't want to shift gears so often in town. I think ultimately I would like to have gearing that would give me somewhere around 4000rpm while doing 75mph (right now it's around 5500rpm).
Click to expand...


Some more math reveals... If you actually have the stock 2.99 final drive, (Which you must, since I don't think there is any numerically higher gear ratios available for our bikes, but I am still a newb...) the folowing is what would result from your rear end swaps:

2.71 Connie bolt-in:

basically stock, what everyone else on here is getting. (see charts above)

2.42 Voyager (more work and customizing)

50 - 3100
60 - 3750
65 - 4000
70 - 4300
75 - 4700
80 - 5000
85 - 5300

IMHO The voyager rear end would affect performance too much, but would probably actually do well for mileage.
 
Hoss said:
the folowing is what would result from your rear end swaps:

2.71 Connie bolt-in:

basically stock, what everyone else on here is getting. (see charts above)

.
Click to expand...

Don't understand what your saying here - if you go from 2.99 to 2.71, that's about 9% difference. Wouldn't your rpm drop for a given road speed?
 
filled up at 100 miles and not on reserve yet- cruised at 75 mph on the highway with some minor stop and go in the city. i did also bounce it off 100 twice. when i filled it up i put 1.87 gallons in it.:headbang:
maybe the cam chain,valve job and new plug wire and boots helped?
 
Holy crud!!! On a ZL900!!! That's better than 50mpg!!! Yes, I'm screaming!!! What rpm are you turning at 75mph?
At a constant 72mph (over 5200rpm) with no playing around I get 29.5mpg.
My best mileage has been achieved going 48mph (in 6th gear) with 36mpg.
 
kawboy said:
Don't understand what your saying here - if you go from 2.99 to 2.71, that's about 9% difference. Wouldn't your rpm drop for a given road speed?
Click to expand...

I knew someone would ask that. I'm not sure how to say it...

I mean if he currently has 2.99 gears in the back, and he is getting the rpm readings as he has been reporting, then if he changes to a 2.71 ratio, it would put his bike back to stock rpm, as long as he doesn't change anything else.

ONLY IF HE HAS 2.99 RATIO NOW! If the only variable is the ratio, that is what should happen. Like I said, if you do the math with a 2.99 rear gear, his bike is acting like it has a 150/70 tire on the back to get that kind of rpm/mph relationship. If you keep the tire size set to 150/70, and change the gearing to 2.71, he would be where everyone else is.

Not sure how to be clear, it doesn't make sense even to me! lol.
 
Hoss said:
Not sure how to be clear, it doesn't make sense even to me! lol.
Click to expand...


Yes makes perfect sense. What is unclear is how one bike is so far off from the majority. I think I would try to borrow someone's tach for comparison.
 
kawboy said:
Yes makes perfect sense. What is unclear is how one bike is so far off from the majority. I think I would try to borrow someone's tach for comparison.
Click to expand...

Agreed. Who knows what the error factor is on a factory tach that's more than 20 years old...

I'm curious tho, why both Willy and dgs seem to have about the same rpm readings and everyone else has what works out on paper...
 
I understand that the factory tach's are not exact but if Willy and I are running worse gas mileage than most, it leads me to believe our rpm's are higher than other's.
 
gds said:
Holy crud!!! On a ZL900!!! That's better than 50mpg!!! Yes, I'm screaming!!! What rpm are you turning at 75mph?
At a constant 72mph (over 5200rpm) with no playing around I get 29.5mpg.
My best mileage has been achieved going 48mph (in 6th gear) with 36mpg.
Click to expand...
70 mph =4800 rpm- I cruised between 70 -75 today. That was one of the hardest things I've ever done in my life.
 
On my first zl9 brandy new with the factory tires I used to fill the tank at 118 miles I was always on reserve by that time. Just wish I could remember how much she took to fill back then.
I used to start looking for fuel around 100 miles but never ran out pushing it to the 118 mark. And cant say for sure but I believe I actually hit 119 miles once before finding fuel.
 
I ride 32miles each way to work and I can go about 65-67miles before I have to switch to reserve.That is riding VERY EASY on the throttle.(Man is that hard to do!:devil:) At 4000 rpm my speedo reads 60mph. At 5000 rpm my speedo reads 70mph.(or 75mph,have to double check). Front tire is 100/90 dunlop-rear tire is a Maxis 150/90. The carbs I am running now are stock... But are also one of the sets of carbs that WillyD was talking about running on his zl900. He let me use them. The carbs i was running could use a TANK of fuel in about 48miles! Talk about sucking. Now with the carbs WillyD let me use I get abot 30-31mpg.not bad i guess. When do you guys hit reseve/ I hit mine at around .8 or .9 gallons left in tank.
 
Ok, since I put in the 136 mains, I got 33.277 mpg riding fairly conservatively. This last tank was more normal riding - went 57.3 miles and put in 1.796 gallons = 31.904 mpg. Next tank will be the fun one - WOT whenever I get the chance - hahaha. Later.
 
I have run a few tanks of gas thru the 1K since getting rid of the crappy hole-filled factory tap and in-line filter with a new pingel installed...I am getting 26-29 mpg...I just think I am freakin cursed and I will never get 35+ like guys are saying here...Next on the list after mid-ohio it is a valve adjustment and carbs are coming off to be cleaned, checked and synced...But I will bet when all is said and done, I will not get 32 mpg...

We shall see....I am starting to believe that these bikes will NEVER get fuel mileage others get...

I am pretty bummed about the whole thing....really
 
Hey Bill, you should make sure that when you buy your bikes that you get ones made on Mondays and not Fridays to ensure you get something good. Your gas mileage is really terrible. We have to get you straightened out. You know what I suggest is that you pay for all our hotel room fees and we'll see that your bike is correct for mpg's.
 
I know why willy gets lousy gas milage......HE'S A MANIAC!

I finnally figured it out...you're a crazy ZL guy... full throttle everywhare you go......0 to 100 in a flash...got that hot rod kawisaki all rev'ed out ......UMMMM HMMMM.... methinks somebody is rompin' the shhh-it out of it!!!

hey willy how long does a rear tire last you??....30 days?....lol
 
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