| Author | Message | ||
     Polekat |
I had a V&H carbon fiber muffler put on my stock exhaust header, a Buell pro series ignition installed, Buell pro series air filter installed and had it rejetted at a dealer. I admit it runs fine (better) and I did test its new performace level once or twice, but a lot of the time I was on the interstate. The motor cycle went from 52 mpg to 42 mpg. This is a 2002 M2. Is this normal? | ||
| Ara |
Mickey, OK, with the new #195 main jet and the stock emulsion tube I've run a tank and a half through the bike and I have some feedback for you. I got 57.9 mpg on the full tank, part of which was two up and high speed and part of it was to and from work which is only 10 miles away from the house. I think it might be a little bit better than what I previously experienced, considering the extra load with a passenger. The other thing I noticed is the idle speed on a cold start at full choke. With the old setup, the bike was textbook. It woke up to about 1,500 rmp and as it warmed up it drifted slowly up to about 2,000 rpm. With the new setup it spends maybe 5 seconds at 1,500 and then immediatly surges to 2,000. If I leave it at full choke it'll go up to 2,200 rpm or so. Not sure what this means. I haven't checked the plugs, mostly because the solid mpg figure probably means it's near optimum. I'm wondering what effects a #190 jet will have. Any thoughts? Russ | ||
| Ara |
Polekat, what size jets did the dealer use and on what basis did choose them? Did he make any other adjustments to the carburetor? | ||
| Polekat |
Ara, I do not know what size jets were put in. It was late, the temp was dropping fast and it was a long way home. I'll have to call them and ask about the jets and carb adjustments on Monday | ||
| Blake |
Russ/Ara, Main jet doesn't kick in till higher speed, nearer WOT. If you are cruising you are on the needle and idle/pilot circuits. Sounds great to me, I wouldn't mess with it. Polekat, Sounds too rich to me. Find out what your dealer did. Only jet change recommended is the pilot jet, from a 42 to a 45. See top of page. | ||
| Stingaroo |
Quick question, is it possible to put a 44mm carb on a stock 1203cc engine? (2001 m-2) If not, what do I have to do to mount one up, besides getting the manifold? Different heads, valves? Brian | ||
| Anonymous |
Quick answer, yes. | ||
| Rick_A |
My highway mileage is ok...around 50 mpg...but in town it sucks...usually around 35 mpg. The throttle is usually to the stop leaving stoplights...I'm sure that doesn't help. I have a Thunderslide kit that is awesome except for needing some low end tuning. | ||
| Blake |
Stingaroo, The real question though is... Why? Unless you are pushing over 95 RWHP, your stock carb is perfectly capable and better suited for feeding the engine everything it can take in. | ||
| Ara |
Blake, Thanks! I'm almost never at WOT - I just don't ride that way. But I'm running a #195 main jet and I'm wondering if I should go to a #190. I recall that was your recommendation based upon your experience with your increased displacement/Nallanized machine. I know I should check the plugs after a high speed run, but there aren't many places to do that in my area. Highest top speed so far is 110, and that was chancy because I was running out of safe road. I appreciate your original recommendation because going back to the H-D emulsion tube and stock jet has produced noticeably crisper throttle response. | ||
| Stingaroo |
Blake, thanks for the input, I maybe able to pick up the carb, with less then a few hundred miles on it for under 100 bucks. I may just pick it up so when I finally am not spending money on college, I can get a 1250 big bore kit, heads, etc. I was just wondering if I could mount it up, and if it would work. Thanks guys. | ||
| Blake |
Ara, If it's running strong, I'd stick with the 195. Stingaroo, Suggest you wait until you can actually use the 44mm carb. You will likely cause problems that will need to be tuned out. | ||
| Stingaroo |
I will take your advice Blake, thanks for guiding this young one in the right way. I dont really need that carb just chillin, and the last thing I need is issues with my bike. | ||
| Polekat |
I talked to the dealership mech today and was told that there was probably a 48 (maybe a new needle) and a 200 jet installed in my 2002 M2 after I had the V&H muffler, pro air cleaner & race ingniton installed. The tuning was done by an experieinced mech. No dyno machine was available. I was told the way to decide on jetting and settings is experience. I am also told that a mile per gallon loss is expected when moving up to go fast parts. I lost about 10 mpg. Any thoughts? 10 mpg seems a bit much. Thanks Would having it dyno tuned help? | ||
| Bomber |
Polekat 48 and 200 are likely both too big, depending on your altitude and other mods (if any) as for dyno time being worth it, well, I can grab both terminals of a battery and tell ya that it's holding a charge, and, on a good day, the amount my teeth chatter MAY give a reasonable indication of voltage. A volt meter, on the other hand, will tell me to within decimal points what the charge is. Experince can get you in the ballpark as to how your scoot is running . . .. . . .the dyno is the meter, though . . . . . . best money you'll spend short of a track day! | ||
| Polekat |
Here in East Troy, WI I believe the altitude is about 933 feet per the gps :-). The mods I listed are the only performance mods made to the M2 (so far). Everything else is stock. I am thinking about a full race exhaust and getting the heads done. I wonder if that would have a big minus effect on mpg. I also have a Givi 755 sport fairing that will be put on after I get it painted. Buell side bags are on it already | ||
| Sickquad |
Got a question regarding the jetting recommendations on the top of the page. Are the slow jet and main jet changes a recomendation for a stock Buell or are they in the ball park for a bike with exhaust and intake modifications? Thanks Chris | ||
| Uwgriz |
I have a question for all those smarter on these matters than myself (should be basically everyone here). I have a 2002 S3T. I have added a K&N air filter, Race ECM and D&D slip-on exhaust. The dealer reset the TPS and timing for the Race ECM. When cold, everything seems fine. When it's hot, when coming to a stop or just revving the engine a little, the idle hangs at ~2000 rpm. If I load the engine a little and lug it down to about 1800, and pull the clutch back in, the idle drops right back down to where it should be. A quick rev and it hangs at 2000 again. Anyone have any thoughts? I'm stumped (but that doesn't take much). Thanks. | ||
| Ara |
Sickquad - Both. I have extensive intake mods and a stock exhaust on my '97 S3 and run a 45/195 combination. Stock factory jets on my bike were 42/195, but the bike surged badly in traffic at steady throttle and it was all but unrideable. I don't know of anybody that uses a pilot jet larger than 45, which is the general concensus and was published in Battle2Win some years back. Uwgriz - I don't have any wisdom for you, as I have a carbureted bike, but I caution you that you have a potentially unsafe situation that should be addressed pronto. Have you consulted with the dealer mechanic who zeroed your TPS? | ||
| Knickers |
Uwgriz, I don't have an answer, but I installed the race kit on my '00 S3 this spring. I noticed the same thing happening when the engine got really hot during the MSF class I took on Sunday. If I let it cool down it goes back to normal. Either we have the same problem or this is a feature of the race ecm. | ||
| Uwgriz |
I'm waiting for a call back from the dealer that did the work. I don't know that the engine is really getting all that hot, at least not anymore than normal plus it was <50° on my ride in this morning. I hope this isn't a "feature." If it is, it's a pretty annoying one. | ||
| Uwgriz |
Oh and just as a side note - this pipe is not for the faint of heart (or ear). | ||
| Blake |
Uwgriz, Check for an intake manifold air leak. Hold the engine at a fast idle (~2,000 rpm), spray contact cleaner or WD40 liberally around each manifold seal (at throttle body and at each of two cylinder heads). If your idle drops, you have identified a leak. Replace the faulty seal. If you don't find an intake leak, you might ask your shop to reverify TPS zero. | ||
| Uwgriz |
Blake, did as you suggested and found no leaks. I took it back to the dealer and they found something off on the timing. Reset and alls well. When I first put the pipe on, the bike would cough once when getting on the throttle at low rpm but this seems to have cured that as well. Thanks for the tip. | ||
| Blake |
Sounds like they checked and set your cam position sensor. That's great news. Thanks for the follow up.  | ||
| Knickers |
Uwgriz, Do you know what they found with the timing? I have the same symptom with the occaisional cough at low rpm. I though timing was preset and unchangeable within the ECM. Kurt | ||
| Uwgriz |
There was a sensor that gets set in position but tends to change that position when tightened down and apparently the tech didn't check to see that it didn't move (which it did). Blake, is that consistent with setting the cam position sensor (having never played with one, I'm not sure)? | ||
| Blake |
Yes, I believe so. The ECM sets ignition timing, but it uses the cam position sensor to determine the position of the engine in it's cycle. If it is not accurately set, it will shift the entire timing accordingly. | ||
| Uwgriz |
Let's see, my bike works and I learn stuff in the process - it's been a good day. | ||
| Eastexsteve |
Just a favor, Can someone save me the trouble of ripping the carb off my M2? If someone out there has a stock needle and a micrometer, I need two measurements. What is the OD of the head (top) of the needle? And, what is the OD of the needle right below the head? Thanks in advance. For you guys still working on M2 jetting, my methods and jetting choices are probably in the archives somewhere. I have a stock M2 with a K&N filter element and a D&D slip on. I live close to sea level. |
