| Author | Message | ||
     Kb123 |
so i bought a stock 2001 m2 with 3,000 miles. stock was a 185 main with a 44 slow jet. i now have a 190 main with a 48 slow jet and the idle mixture at 3 turns out. jet needle has shim. crisp acceleration under 3000rpm. below still some surging. really annoying. idle mixture makes no difference to idle. i assume i have over jetted somewhere? suggestions? i have a 45 slow jet i can put in. i also have the nokh jet needle that came with carb kit. thanks. love this bike. | ||
| Outdoors |
I have a 2000 M2 with race intake and supertrapp slip on exhaust. Mine is running the 45 jet with one thin shim and is happy just over 2.5 turns out. If you have the 45, I would try that, especially if still running the stock intake and exhaust. | ||
| Kb123 |
so is this under 2500 rpm burble just a part of the 1200 v twin motor? i am new to this layout. air fuel screw still doesn't change anything with the 45 jet. is there any place where i may have a blockage. i sprayed out all of the obvious places. thanks | ||
| Outdoors |
Well, if you can turn the air/fuel screw all the way from in to out with no change then you have an issue somewhere. Perhaps a complete strip and clean is in order. Intake leaks around the intake manifold are also a frequent cause of rough running. Spray some WD-40 around the intake area when she is running to see if it speeds up. The knowledge vault and search engine are your friend for suggestions. If everything is working as intended, then try it at 2.5 turns out. Once the motor is warmed up you turn the screw in until it begins to stumble, then back it out until it stumbles. The sweet spot should be in the middle of those settings. Due to the exhaust, it is pretty difficult to perform this adjustment without a flexible screw driver or many burns! If still running the stock airbox and exhaust, some improvements in breathing should be considered. There are several aftermarket kits or some have achieved excellent flow by tweaking the OEM intake and fitting a K&N filter. Search the forum or send a private message to Buellistic. My M2 is happiest above 2500 rpm and does not like to chug along like my Sportster would. I attribute that to the lighter flywheel in the '00-'02 Thunderstorm motor. At parking lot speeds I often have to feather the clutch some. Sort out the air/fuel screw issue and go from there. I'm a user and not an expert by any stretch, so seek out advise from some of the more experienced Buell riders of the forum that talk the CV carb language. Avoid advise from well meaning Sportster guys because their jetting requirements are significantly different from yours. Sort that little issue out and the M2 is the best of all tubers in my somewhat biased opinion. | ||
| Jayvee |
Hey Outdoors, how "thin" a shim" ? That's my next thing to try. I'm at practically sea level, run a 190, and a 45. | ||
| Outdoors |
how "thin" a shim" ? A friend of mine is a Harley/Buell technician and Buell owner/rider. He gave me a shim to use and I did (without measuring it). Most any of the Harley shops should have various shims about for tuning the older bikes. Give it a try. | ||
| Bluzm2 |
Shim is usually about .050" | ||
| Kb123 |
so i finally cleaned the carb. there is a small jet or passage next to the main jet and the idle jet. used a bread tie with the paper burned off to probe the hole. learned that from my norton's amal carb's. wire is soft enough not to do damage or open this up to big. at first only went in a short bit. with gentle probing, carb cleaner and air hose now goes almost 3/4 of an inch. will see if my air fuel adjuster will now have some affect. | ||
| Koz5150 |
Guitar strings work well for that also. Very stiff and come in multiple diameters. | ||
| Buell_bert |
Torch tip cleaners may work also at times for cleaning small ports. | ||
| Bluzm2 |
A single wire from a wire brush usually works for me. | ||
| Kb123 |
what is this opening? i can clear about 1 3/8 inches. is that good? there is also a cluster of 5 small openings in the throat of the carb about mid way. i have put the wire in those. only goes a short bit. thanks for your input. | ||
| Jayvee |
I found some brass #4 shims at the local hardware store. They are about .022 to .023 thick. I added one of each, for a shim of .045. You'll never guess, when I took the carb top off, there was a little metal washer laying in there. It looked like someone had tried to shim it before, but it fell off when they put the needle back in, and they didn't notice. I bought the bike with a V&H muffler, and the Race Kit K&N intake. The idle air adjustment screw cover had been removed already. The jets were the stock jets though, like a 42 and 200. Now it's 190 and 45, and the needle shim. I could feel the difference right away. I'm not sure how to describe it. But it seems to run fine though. (Message edited by jayvee on July 04, 2010) |
