How do I increase my fuel mileage?

[jfeagins]

....I appreciate all the advice but honestly like I've said a few times.. Carb set up confuses the hell outta me....

Here's something I ran across that helped me, more than anything else, to understand the carbs on my 85. Worked so well, I have two of them in the garage right next to my 85, and any time I get carb confusion I can turn to one of them and get it straightened out in a hurry.
http://www.ebay.com/itm/Yamaha-V-Ma...=231133156741&pt=US_motorcycles#ht_102wt_1223
Perhaps it'll work for you as well? :biglaugh:

FYI, FI isn't all that easy to tune correctly either.

 

[naughtyG]

I think your 90 miles (is that before reserve?) is actually pretty good for a stage 7 on stock exhaust.
I've had two '86 models with stock carbs / Jardine slip-ons and the best I ever saw was 105 miles before fuel light, so you have a little room from improvement.

I wish my max EVER saw 120 miles (193kms) before reserve..

Bigger tank is good - I have one of those german-made 21L plastic ones, and that's a great help, even if it only adds 6 liters.

 

[snakecharmr]

I think your 90 miles (is that before reserve?) is actually pretty good for a stage 7 on stock exhaust.
I've had two '86 models with stock carbs / Jardine slip-ons and the best I ever saw was 105 miles before fuel light, so you have a little room from improvement.

I wish my max EVER saw 120 miles (193kms) before reserve..

Bigger tank is good - I have one of those german-made 21L plastic ones, and that's a great help, even if it only adds 6 liters.

Ya I suppose I shouldn't complain too much as I'm sure those 80 miles will go by quick enough that stopping to fill won't be an issue..lol My 2006 KLR650 would have a range of 500kms with a 21L tank.. Guess If I want range I'll pick another one of these up as a second bike.

 

[thor_eyerdhal]

I have a Stage7 with Strapps (almost equal to stock exhaust), i tuned it with a wideband 0² meter (innovate).
To reach the correct AFR at cruise, low speed and wot, you need to :
-Put 147.5 main jets with S7 needle
-Needle clip on the second groove from top
-Stock PAJ2
-2.5-3 turns for idle fuel mixture.

175 and even 165 DJ main jets provided in the Stage7 kit are WAY too big with stock exhaust or slip ons!

 

[snakecharmr]

I have a Stage7 with Strapps (almost equal to stock exhaust), i tuned it with a wideband 0² meter (innovate).
To reach the correct AFR at cruise, low speed and wot, you need to :
-Put 147.5 main jets with S7 needle
-Needle clip on the second groove from top
-Stock PAJ2
-2.5-3 turns for idle fuel mixture.

175 and even 165 DJ main jets provided in the Stage7 kit are WAY too big with stock exhaust or slip ons!

Sounds about right and what the Previous owner had done as well. It's still all mumbo jumbo to me though.. what kind of hp and mileage are you getting?

 

[rspauldi1]

Great info Thor..
can you explain what happens to AFR's when vboost kicks in?
I currently have vboost set to come on at 3k.
If just out hwy cruising would It benefit switching the vboost to the 6k position? This being from a gas mileage perspective.

I don't full understand vboost. I would really like to see an AFR plot/graph of idle to 7k RPM to see what is taking place with the fuel mixture.

thanks,
rick

 

[Redbone]

Vboost in simple terms is when it's open one cylinder is fed by two carbs.
So it is taking in a lot of fuel and air for each cylinder when open, but on the upside is that all that air and fuel should be making you smile.

 

[Biker Dash]

At this point I'm really considering figuring out an extra fuel tank...lol

Mr. Charmr-
Check out
http://www.tourtank.com/

Lots of options, reasonably priced.
As for the Venture final drive - I used one this past summer, mileage increased by about 25 kilometers/tank. If you can get one at a reasonable price, it will pay for itself in no time, especially if you are tanking up in Canada.
Bonus -using the drive lowers the rpm by about 500 in all gears, consequently in top gear at 100kph it's about 3800 - which is below one of the "rattle zones" (4k-4500k) that the bike goes thru. Bottom line- much smoother ride at legal highway speeds.
Cheers!

Yeah, the Venture drive would be an excellent route, if you would like to boost your mileage. It's just like a very popular mod with the chain drive Shadows (goin from a 41 to a 38 rear sprocket)

"rattle zones" (4k-4500k)

What you mean, "rattle zone"?

 

[PATMAX]

Honda CB 250

 

[rspauldi1]

Thanks for the input Redbone..
but do you know what happens with AFR's when vboost kicks in? does it go really rich?

My vboost is set to open up at 3k. when crusing down the hwy at 75MPH i'm taching at ~4k, so vboost is open while crusing. if I have a handlebar switch that I can change between the 3k vboost open to 6k vboost open would I beneifit, gas mileage wise, by switching vboost to 6k while just crusing.

 

[Redbone]

I'm not sure of what happens to AFR when vboost kicks in, maybe someone with a wide band AF setup or has some dyno time will chime in to enlighten us.

 

[Fastatv]

I've got an 85 with a ton of mods from previous owners. I'm still trying to sort out what all has been done to the bike internally and probably never will. Heres what I do know

Stage 7 kit
drilled/modded stock exhaust
fan only works with toggle switch

Apparently it only gets 140kms or so on a tank of fuel. I'd like to get this closer to at least 180kms maybe more.

What steps can I take to get closer to my goal without neutering my max?

Another way to increase mileage is how we ride. When I was doing alot of riding, slow riding in particular, I would always run in fifth gear, at 35 to 45 mph. In my mind, this was easy on the bike and lower RPM's meant better mileage. :ummm: I was wrong! I found that I got several more miles per gallon when I had the R's up a bit more. I know, sounds totally backwards doesn't it :rofl_200: Anyway, brought this to the forums attention and strangely enough, many agreed with my findings. unk:

 

[Marc85]

Previously I was doing about 115miles to reserve light, after putting on UFO 4-2-1 full header and jetting to 155 mains I'm now hitting 130mi to reserve light going just under 80mph. **Note I also live a mile above sea level. I've heard of people jetting anywhere from 160-170 mains at sea level.

 

[Traumahawk]

For 160-170 mains.....is that Mikuni jets....or dynojet jets, because they dont flow the same and arent rated the same.

 

[Marc85]

For 160-170 mains.....is that Mikuni jets....or dynojet jets, because they dont flow the same and arent rated the same.

155 Mikuni jets are what I have in it.