Horrible MPG

[DaylightDies]

What did i do wrong?

Im breaking in a BBK 70cc taiwain import.
fully ported and everything.
19mm arreche carb - jetted (im sure its around the correct jet)
uni air filter
leo vince zx exhaust

97 yamaha jog

and im getting ~30mpg or something bad around there.
Is it just because im still breaking it in?

[Bear45-70]

Why are you sure it is around the right main jet? What does the spark plug look like after you have run the scooter? Generally poor fuel ecomony is too rich on the jetting. Yours is probably made worse by the new BBK.

[DaylightDies]

Why are you sure it is around the right main jet? What does the spark plug look like after you have run the scooter? Generally poor fuel ecomony is too rich on the jetting. Yours is probably made worse by the new BBK.

I just started the break in process yesterday, i take it 4miles to work and 4miles back slowly and havnt had time to check my plug. I can check it tuesday :/so it could be too rich? but How would it be so low. I mean i can understand dropping to ~60mpg. But 30? I dont have a v8 hah

I wanted to post this before i go to bed. Been working over time this past week and get maybe 20-30mins to eat then crash into bed.

Im not 100% sure its the right jet, but im using my jet settings based off of burnt_toasts' jog build (which is currently my jog)
and as we are maybe within 15miles of eachother the jet should be relatively the same.

I have a few jets to mess around with and I plan to do so. But I wanted to break the BBK in and get it ready for anything else I do to it, to get proper results out of it.

I run it for about 15mins 4 miles, 2x a day and i run through half a tank in the process. How long till it should be broken in?

Also thank you for such a quick reply!

[z50r-ghost]

sounds right on to me.... BBK w' a 19mm carb / rich jet equals about 1/2 the fuel economy you had when stock. It will get a *little* better when you complete break-in and go leaner, but it will not even be close to what your Jog was when it was stock.
My Aero is terrible on gas, but worth it in performance.

-if you premix or add oil to your tank when you fill up, be sure to have an extra bottle of oil with you all the time because you will be hitting the gas station more often!

later, j

[DaylightDies]

sounds right on to me.... BBK w' a 19mm carb / rich jet equals about 1/2 the fuel economy you had when stock. It will get a *little* better when you complete break-in and go leaner, but it will not even be close to what your Jog was when it was stock.
My Aero is terrible on gas, but worth it in performance.

-if you premix or add oil to your tank when you fill up, be sure to have an extra bottle of oil with you all the time because you will be hitting the gas station more often!

later, j

Ouch :/ I was hoping to get atleast 55-60mpg out of my parts.
If i drop to a 17m? or maybe even back to stock, do you have an estimate on the mpg?
I have jets to go leaner, which ill do soon.

As for the oil/premix im still running the oil pump and adding about 6-8% of oil to the tank which should be about the right ratio.

[eliteguy50]

Once you break it in, you can also upgear for better fuel economy, but it will take a while for the fuel savings to pay for the gears.

[DaylightDies]

Once you break it in, you can also upgear for better fuel economy, but it will take a while for the fuel savings to pay for the gears.

Know any good jog part sites?
If it gets me back/forth to work while saving fuel, its making me money anyways!

[eliteguy50]

Once you break it in, you can also upgear for better fuel economy, but it will take a while for the fuel savings to pay for the gears.

Know any good jog part sites?
If it gets me back/forth to work while saving fuel, its making me money anyways!

Off the top of my head, no. VT cycles has the gears but their site is not up to date, you have to call them. They could also tell you what jets you should be running.

[customx22]

Call Motosource Hawaii they only deal with jog they make make sick jog builds they have everything for jog

(808) 952-9253

[Trafficjamz]

I get 30mpg on my 86cc with a 30mm carb jetted to 160 on the main?

How big is your jet? a 19mm carb should be better MPG than that.

[DaylightDies]

Thnx for the motohawaii and vtcycle tips. I will be giving them a call soon.
I ordered in some new parts. As for the plug.

I pulled the plug and According to... http://1.bp.blogspot.com/_Zl3HQgWfsPc/T ... -chart.jpg

Im a 7/8 Black on the outside Caramel on the inside! So im not to rich, but it could use a smaller main.

I havnt ran at WoT yet. Infact I havnt ridden the jog for over a month (not by choice..).
Tomorrow I will be getting her a new battery and get a new bolt for the exhaust! That way she will run like a beauty again!
I will order some arreche jets soon. I'm running a 100 jet. I have a 95 and a 60 Main as well. if the 95 doesnt cut it ill buy a 90 and an 85 just to test them. Which I presume I will be doing anyways.

[maddog]

i get 28 miles to the tank on my aero

[Johnny5]

WOW. I did not know that the fuel economy becomes so dismal with heavy Modding. As a newbie to bbk's, I'm sure glad I have a 1.3 gal tank. The Aero had half that.

Would it be safe to say that your fuel economy reflects the output of your build. Example. Stock your scoot made 3 HP, but now it makes 6hp. Would it in turn consume twice as much gas?

[eliteguy50]

WOW. I did not know that the fuel economy becomes so dismal with heavy Modding. As a newbie to bbk's, I'm sure glad I have a 1.3 gal tank. The Aero had half that.

Would it be safe to say that your fuel economy reflects the output of your build. Example. Stock your scoot made 3 HP, but now it makes 6hp. Would it in turn consume twice as much gas?

It is not that drastic. A lot has to do with how you tune and the carb size. The same motor running a 21mm carb will get better fuel economy than with a 30mm.

[Bear45-70]

High performance is not free, ever.