Unless my calculator is broken, and my brain has gone on hold, the mileages I have stated is correct. I am running a 40 pilot, 187.5 main on third clip. with 2.5 turns. Not saying that is what any one else should run! K&N Bak. cobra powerpro hp 2 into 1. With extra baffle. I don't monkey with it.. been that way since I got it running right after installing aftermarket goodies.. Change Oil and plugs, regularly and use a little MMO in it occasionaly.

vegasdave,if you have 30mins to waste try moving the needle clip up 1 slot closer to top/bunt end then installing a thin spacer washer under the needle clip.

Doing that will effectively /ever so slghtly lean out your cruise mixture just a tad (1/2 step not full slot step) which i have found in most cases isnt enough to make the bike run too lean but doing that could maybe inc your avg mpg from your current 36-40 to 40-44+mpg.

Let us know what what that did for your mpg if you decide to try it out someday.

Scott

Oh Yea, forgot to mention.. My bike as never had in alcohol diluted gas in it...

Scott : I`ll be installing a new fuel pump(my crapped out this past weekend)so maybe I`ll get it a try.Was I time i tryed different settings listening to all these high MPG
stories and it just.....got.....old.Seems like i was always jettn it instead of ridin it.

thanks for the replies, but I still have a ton of ?s. after the bike is warm I noticed if you rev motor guessing about 2500 -3000 it pops one time after release of throttle. is this normal?

hey curt, do you think going to 37.5 pilot will help mpg?

Rick, most find the 37.5 pilot too rich and usually your milage will go down if installed

hmm, could only do a quick reply, but any way, going to a larger pilot will decrease mpg's. I would suspect a leak at the manifold since you have white plugs up front. Suggest using starter fluid, quite volatile and will find the smallest of leaks.

vegasdave,if you have 30mins to waste try moving the needle clip up 1 slot closer to top/bunt end then installing a thin spacer washer under the needle clip.

Doing that will effectively /ever so slghtly lean out your cruise mixture just a tad (1/2 step not full slot step) which i have found in most cases isnt enough to make the bike run too lean but doing that could maybe inc your avg mpg from your current 36-40 to 40-44+mpg.

Let us know what what that did for your mpg if you decide to try it out someday.

Sorry, but for some reason only quick reply works for me
Any way Scott, if you have ever read the Mikuni 42hsr carb tuning manual, it does state that moving the needle up or down has no effect on cruise mileage below 70mph:
Poor milege at these speeds can
be corrected by fitting a leaner
needle. Raising or lowering the jet
needle has no effect on fuel mileage
below about 70 mph.
and I see no reason why this would not hold true in the stock carb. And I did try this out on my 42, Mine is set on 2nd groove, usually I would get 40mpg at 80mph, going to the 1st groove was up to 45mpg, and this was done on a few tanks and checked a couple of times, my 65mph cruise stayed the same mpg (50) in both clip positions. But at the same time, clip position will affect acceleration performance. For the 42 carb it is the needle that effects mpg at cruise, that is the straight portion, just above where the taper begins, the 42 has 4 needles specific to this carb, all the same length, but it is only the cruise portion of the needle that changes needle to needle, and is only .o1mm difference from needle to needle. but in my experiments between the standard 97 needle to the leaner 98 needle, without changing the main, pilot jet, pilot screw, just swapping the needle only and using clip in same groove and doing a 65mph 100 mile run, I picked up 8mpg, consistently.
It doesn't take much throttle twist to eat gas, if the carb is set correctly.

erbman,no disrespect meant at all as your a very good tuner and have a good working background with the R*'s . But i also have plenty of carb tuning (slide & CV) experience on bikes over the past 38 yrs riding them on the road inc recently my R* with stock CV carb too. And i generally find changing clip placement/lvl on needle will change mpg @ cruise unless maybe your cruising 1 up on a non loaded bike at 1200-1500rpm on a straight lvl road with no headwind ,no tall windscreen and tall gearing with very light throttle position where your not quite enough into the throttle to get where needle has more effect then pilot/pms setting does which isnt the case most of the time the way your avg person rids these bikes.

But thats not your avg cruise cond for most people so in general i find when you change clip position it will affect cruise mileage esp on interstate at 65-70mph when riding 2up with bike loaded ,tall wind screeen ,maybe headwind etc that requires considerably more throttle getting plenty far enough into carbs main circut where needle position does affect it unlike the not so avg cruise cond i already noted above thats usally not the norm.

When i 1st got my bike it was running a little rich got mid -upper 30's mpg arround town riding 1 up/just me on bike. I then clip 1 notch to lower needle some and fuel mileage went up right off the bat still riding in town and country roads at 45-55mph at lower rpm/light throttle position . But then it would feel a smidge lean once in a while after that so i recentlyed a thin washer underclip for needle to get a 1/2 step up to richen it a tad and wala. The slight lean soggy feeling at light throttle postion went away and the motor felt crisp/responsive thru all throttle postitions again but withut being as rich as it was prior ,pms was at 3.25-3.5 with stock 35 pilot ,stock aircleaner,but with afermarket pipes with baffles. But the fuel mileage only dropped 1-1.5 mpg with the washer added for slight enrichemnt and still got better mpg then where it was to start with esp on the open road on recent trip.

Just did a 600mile trip with wife on back ,bike's 4 bags fully loaded ,windscreen in tallest position,etc and got a low of 42.5(75mph+) and high of 47 mpg (68-70mph) with the faster 75mph+ cruise speed and more headwind being reason for the lower 42.5 mpg reading.

I have always found the needle clip setting can in fact affect cruise mpg more then people think or Mikuni states even at slower cruise speeds/light throttle postions due to the reasons i already stated .But it doesnt affect idle mixture and @ very light thorttle postions. Thats coming from my 38+ yrs of 1st hand experience riding and tuning carbs on bikes on the street with std slide & CV carbs .

I will be curious to if Dave tries raisng the needle clip 1 noth then installing a thin washer under the clip to see if that inc fuel mileage some .

Scott