This is very interesting, I have a 2004 Midnight Star 1700 and have experienced the same issue with gas mileage and running rich. I had V&H slash cut's installed when I purchased the bike new. The dealer installed the jet kit when they did this. They said the carb had to be rejetted for it to run right. It has alway's run rich, I've had two different shop's adjust the carb and have had the same result's. The mileage is about 38-40 at speed's 50-60 and drop to around 32 when I run 70-80 on the interstate. I am new to the forum, where can I get information on how to rejet and adjust the carb myself? a little scary, but I'm willing to give it a shot.

Sundance

Well, since I rejetted & install BAK, pipes, ported manifold, my gas mileage has suffered to, but I contribute that to I just can't keep my wrist out of it. Before I did upgrades I was getting 44-50 mpg with all the mods I avg. about 40-44. But its sounds good, love the noise & she’s running great

running the larger pilot seems to be the biggest culprit for mileage being poor,
The wrist twist places second, listening to the pipes.
I have read so many of the carb setup discussions trying to be sure I have it right, and Keep any chance of SVS away. Been in the carb so many times know and only had the bike for just over a year, but all info from this forum has been right on. Never have had it run bad, just always adjust it leaner till it fails the WOT test... but having the larger pilot in can compensate for a lean main most of the time and that is what we run in most of the time (stop and go -low RPM). so be sure to start with the pilot get that happy and move on too the Main...
There was also a discussion about the choke(enrichner)about it not shutting off all the way, make sure it works properly.

I avg about 44 mpg doing 80 on the eway, hit reserve around 170 and if I cruise in a rally 40-55mph get about 48-50mpg can push to 190 b4 reserve.

Hey sundance

Go to the "Tech Articles". There are some good articles in there under Carburetor that will give you a good start.

i have only had me 99 roadie since oct have put about 1500 miles on it if i run 87 octane in it mileage will be around 40 +- but if i run 93 octane in it mileage goes to around 50. and i know for what i have read on here 93 is to high of octane . bike has no mods. and only around 3800 miles. i do get on the rev limiter at times . not really a bike mech. i am a diesel and hydraulic mechanic. and we also drag race mustangs. i enjoy the site and have learned a few things by just reading the post.

Hey guys thanks for all the good info. I have a question though, I am still waiting on my guy to tell me what the exact sizes of the jets are. But i do remember that the kit had two paths for the instructions. One way if your leaving the stock air box on and the other if you are putting high air flow air cleaner on. The dealer put the bottom jets in for a high air flow cleaner. Boy she was super rich with that setup since i have the stock air box with a K&N air cleaner in it. My guy that made it run right but i have the gas mileage issue with put in the bottom size jets for a stock air cleaner. Now that you know that i was thinking what if i put on the V102 open air cleaner from Yamaha to compensate. Do you think that would help the mileage any? It runs great and don't smell rich.... What do you think.

Brad

We really need to know what you have in there. It would only be a blind guess otherwise. You have to try pretty hard to get these bikes too lean. And if you do get it too lean it runs like crap or not at all so you won't be riding it and doing damage. So if you are worried about that I wouldn't. I can give you my settings just as an example.

1700 motor
Cobra Lo-Boys
BAK
Ported manifold
167.5 Mik main
stock pilot jet
Clip in 3rd groove of the needle with 2 washers under the spacer
PMS around 2 1/2
Accel screw all the way down on the nut

This is what i have found out its running a 175 main jet, it has the037 dynajet pilot jet, the dynajet needle is installed with the clip in the #4 grove from the top, with all the stock washers. The mixture screw is 3 turns out. It was pretty much setup as the stage 1 kit instructions specified. What do you think. I noticed that my main jet is much bigger than your modified bike Musky.

BradsbigV wrote:
This is what i have found out its running a 175 main jet, it has the037 dynajet pilot jet, the dynajet needle is installed with the clip in the #4 grove from the top, with all the stock washers. The mixture screw is 3 turns out. It was pretty much setup as the stage 1 kit instructions specified. What do you think. I noticed that my main jet is much bigger than your modified bike Musky.

If you have the Dynojet main your's is leaner than mine. The difference between Dyno and mikuni jets can confuse people. The numbers aren't interchangeable. Mikuni numbers are the flow rate in CC's per minute and the dyno numbers are the diameter of the hole in MM's. Which main do you have?

A 175 Dyno main is equal to about a 163 Mikuni.

As far as the pilot jets go i'm not sure how the numbers work. But if you have the 35 Mikuni stock pilot try that. As long as you have the K&N in the stock airbox you might want to try the poormans BAK. Here's the link. Poormans

what is the link?