Author Topic: 26 mpg?? whats wrong? (Read 4066 times)

Vee Dub Nut · « **on:** September 19, 2005, 11:54:36 AM »

Ok.. i only got 81 miles before i filled up the bike the other day. I put in 3.07 gallons of regular.. that comes to about 26mpg....

Something is wrong, i should at least be getting high 30's....

1st Gen B12
127.5 mains
stock pilots
around .04" shims (a little more than 40 thou i think)
stock filter
2" mod
A/F screws at 2.25
D&D bolt on

I need to do a valve adjustment on it soon.. but other than that, it only has 8k miles on the bike.. When i first bought it, I was getting 38 mpg with stock mains, A/F screws way out (not sure how much but i never had to use choke) and 1 shim (little over .02")

Im a bit confuesed.. it seems to run ok.. when it gets warm, it bogs a bit off of idle, nothing bad though...

Any suggestions?

jfudo · « **Reply #1 on:** September 19, 2005, 12:16:08 PM »

I just did some mods to my bike this weekend, it is identical to yours except two bros. exhaust. It seems to run pretty good, but it starts smoking something fierce while idling. I don't know what I did wrong. It didn't do that before I put the bigger mains in. It certainly idles rich now, which I'm sure would result in poor mileage.

tacoman · « **Reply #2 on:** September 19, 2005, 03:28:32 PM »

When I did my B6 carbs I noticed fuel consumption up some. My tailpipe seemed a bit black and sooty and throttle response was sluggish. I went from 2 to 1 shim under the needles and things are much better. I think the B12 has clips instead of needles but I'd start there.

Red01 · « **Reply #3 on:** September 19, 2005, 08:30:48 PM »

US (and I think Canadian) version 600 & 1200's don't have adjustable needles, but many other markets do.

But back on topic, I'd try a little less shim, too. You should be getting at least 10mpg better than what you've got.

Vee Dub Nut · « **Reply #4 on:** September 20, 2005, 03:07:42 AM »

im going to keep working with it.. i'll keep yall posted

B12Teuton · « **Reply #5 on:** September 20, 2005, 09:02:10 AM »

Not so much full throttle!!

oremike · « **Reply #6 on:** September 20, 2005, 09:17:28 AM »

I'd start with the easy stuff like is the air cleaner dirty? Then I'd look for other problems. My piped and jetted 2002 B-12 gets 37 mpg. When I first installed the Ivans Jet kit I put the needle clips in the lowest postion rasing the needles as much as posable. I got 27 or so mpg and the bike only ran well at WFO throttle. I moved the clips to the mid postion and changed my air cleaner,my all around preformance is much better and mpg is up to.
Miike M.

GSF1200S · « **Reply #7 on:** September 22, 2005, 09:41:05 PM »

Have you checked the float levels?

slo coach · « **Reply #8 on:** September 23, 2005, 08:51:12 AM »

Vee Dub Nut....if you can try and keep that front wheel on the ground i'm posotive you will find the bike more economical.

slo coach