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Discussion Starter #1
From what I'm seeing in another thread, it seems that my 29 MPG (US) average, with lows around 25 MPG & highs around 34 MPG, is a good bit worse than what other people with Mikuni-carb T3s are getting. Anyone got any pointers on where to start looking to improve it? I don't think I'm riding like a hooligan, & I get better mileage with a steady 70-80 MPH in 6th than I do going slow...

Thanks,
-Kit
 

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I thought the tridents, sprints, etc. got about 40mpg. The super III and speed triple (maybe daytona?) only get a bit over 30.
 

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34 mpg UK ~ 29 US.

If you get better mileage crusing at 80 mph than you do on average, it does look like your riding style is forcing the high consumption. Either you use too many revs (low gears) and/or a lot of hard acceleration/deceleration and/or a lot of high-speed cruising. Fuel consumption at 100 is about twice that at 60.

If the above isn't the case, and the bike guzzles fuel quicker at let's say 40-50 mph in 6th than it does at 80, you are probably running way too rich idle mixture. At higher speeds and throttle openings, this has less influence, but with a high vacuum and low throttle openings, it can richen the mixture so much that it doesn't burn cleanly and fuel is wasted while power is down. The cause can be not properly closed choke pistons or too rich idle mixture from too large idle jets and/or idle mixture screws turned out too far.

[ This message was edited by: faffi on 2006-11-21 12:50 ]
 

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My old Trophy 4 and my dad's old Trophy 3 got about 34. I honestly thought that sucked. My 02 Triple gets about 48, oh yea!
 

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My 900 Sprint was getting in the high 40's most of the time before I rejetted it. One trip to Laguna Seca in 2003 I averaged 48 for the trip. I was never happy with the way it ran though. I have clocked up to 52 ! believe it or not. It was way too lean ! I'll have to check it now it has the new setup.
 

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Both 95 Trident and 95 Speed Triple at 42 MPG although the S3 isn't quite right and is about to get a dynojeting so that might be a bit off. My Trident was 8 months old when I bought her and she would return 42 mpg (UK) regularly under 80mph.
I would check needles and jet sizes, that was a big factor with the T3, I was getting horrible gas mileage, around the 20's before I cleaned and reset the carbs. Balancing is very important and the smallest correction will make a big difference.

Hope this was some help

Cheers
Nic :-D
 
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Discussion Starter #8
Thanks, everybody! I guess I am getting about what I should expect, considering that 95% of my riding is stop-n-go in the city. My carbs were checked for balance this Summer at the 30k service, & it sounds like it would be worse if my jetting was off.

Cheers,
-Kit
 
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Discussion Starter #9
Thanks, everybody! I guess I am getting about what I should expect, considering that 95% of my riding is stop-n-go in the city. My carbs were checked for balance this Summer at the 30k service, & it sounds like it would be worse if my jetting was off.

Cheers,
-Kit
 

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I regularly get 45-52 with my 1995 Sprint Sport with 36,000 on the clock.
 

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Kit,
I have noticed that my bike has been running rich. I believe moto's post carries a lot of weight. I plan on a tear down and rebuild of the Mikuni Wonder-Carbs this winter. I have gotten a high of 40 mpg (driving like a granny) and a low of 30 mpg (hooligan).

BTW how are the bags working?

andyforbes,
Did you rebuild or rejet in the recent past?
Zip
 
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Discussion Starter #13
All: I just replaced the bodywork on my bike & noticed that my petcock is a dirty golden-brown color & smells of gasoline. I suspect that part of my mileage problem may be related to that. The fact that my mileage improves significantly on long highway trips might just have something to do with more gas going into the motor than leaking out of the fuel tap.

Moto: I may bug you for some advice if I can ever spare the cash for a set of Keihins.

Zip: Now that I've gotten the brace off of my tire, the bags are great! I went to the grocery store the first day I had 'em on & picked up, among other things, a 12-pack of Newcastle bottles, (6) 1.5 liter sodas, & a gallon of milk. Easily twice as much as I've ever been able to carry before. The backpack I carry to & from my clients just fits in a bag; my back is feeling much less abused now. Thanks again. :-D

Cheers,
-Kit
 

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A drop of fuel spread around the petcock is enough to collect dirt like you decribe - if the tap is leaking enough to notice in consumption, the tap and even engine below would be wet and stained and it would all reek terribly from fuel.
 

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. . . . . er . . . . so my 55 MPG (on a run) means I'm riding wayyyyyyy too sensibly eh?

Checked it out for the third time (over three weekends - and about 230Km's each time) - and it converts to between 53 - 56 mpg!
 
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Discussion Starter #16
Eh? Did you pick up an old 885 triple, or are you just rubbing our noses in the fact that the 955i models get better mileage? :razz:

All in good fun, hope you're having a loverly Summer while we freeze our bits off up here. :-D

Cheers,
-Kit
 

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My speed triple is around 40 riding like a granny. If I crack the trottle in a normal fashion it gets around 34 to 35. I have the old mikunis. factory jet has the needles and needle jets. mine has the problem and has for many years I only recently realized what it was it has always run soft when cracking just off idle and I had always thought that it was just the idle mixture. only thing is I have never been able to get the mixture quite right. after seeing factory jets commments on the problem and some of the posts here I realized what it must be. I will probably replace them this spring and use them until I do the next motor, at which time I may step into the keihin fcr's.
 
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