| Author | Message | ||
     Phaedrus91 |
My 2000 M2 is jetted for about 6500 feet for the mountains of New Mexico (yes I know it is hard to believe but we do have mountains). And I will be moving the bike to Keene Texas (one stop light town, south of DFW). And the elevation there is 1000 feet. What jetting should I run? I would like it to run from 1000 feet and up. I do not plan on going lower than 850 feet but I would like to be able to go up in elevation by a few thousand. I will be riding the bike from Keene to Albuquerque, New Mexico. Which sits at about 5000 feet. I am expecting it to run rich but do you think that if I jetted it for about 2500 feet that it would run well enough in Texas and New Mexico?? | ||
| Beardo |
This is unrelated to your post and apologize. Are you the same Phaedrus that was on the XR1200 forum? | ||
| Dave_02_1200 |
My 2002 M2 is jetted as follows with a Forcewinder intake: #200 Main Jet #45 Slow Jet Mixture Screw out 3 1/2turns 3 Radio Shack shims under the needle I would start there. A little rich is better than too lean and my Buell runs well from sea level up to about 9,000 feet. As altitude goes up the bike does run a bit richer but it runs great that way. (Message edited by Dave 02 1200 on July 13, 2013) | ||
| Phaedrus91 |
Hey Beardo. Nope. Must be a different Phaedrus. I'd guess that fifty guys on the buell/Harley forums have read zen and the art of motorcycle maintainer and that that it might be a good screen name.... My dad has an XL and loves the book. Maybe it's him! and Dave thank you for the info. Now to order some jets. Also something I forgot to mention. To get from Texas to Albuquerque I have to cross a mountain pass that is 7200 feet. What are the odds that a cv can adjust enough for that. Either way it has to run well in Texas I suppose so it doesn't really matter if it will run at 7200 or not. | ||
| Jayvee |
If somebody goes on a long tour, or like an Iron Butt Rally, and goes halfway or all the way across the country on a carbed Harley, they don't stop to change the jets according to the elevation do they? Like big old Harley FLTs and stuff. Maybe they just put up with it until it got better? | ||
| Beardo |
He was an older fella, for sure. He just disappeared. I loved reading his posts. Lots of knowledge and different perspective. | ||
| Ratbuell |
See how it runs first... Keep in mind, as you go lower, it will run LEANER. More air down low than there is up high. | ||
| Dave_02_1200 |
My jetting is so it will be just right at sea level but it seems to work fine in the mountains too. It does get richer at high altitude but the main thing I notice is that in thin air the bike makes less power. If you get to a higher altitude and want it to be a bit leaner you can always give the mixture screw a turn or two. There is enough overlap in CV40 circuits to allow the mixture screw to have some influence across the range. | ||
| Phaedrus91 |
Beardo - sounds like the Phaedrus on th XL forum was THE REAL Phaedrus. Making deep comments full of wisdom and knowledge and then just dropping off the map.. I guess that the best set up would be if it was tuned to run at about 1000 or 1500 and just let it get rich when I am going back home for spring break.. (college student in texas whose family is in New Mexico, no car, just m2 and a dr200). | ||
| Cyclonecharlie |
Tune it for your local area...running it too lean will do serious damage to your motor. When you take a trip to high elev. carry an extra set of plugs one heat range hotter(only use if sounds like it's fouling out)just for high elev. | ||
| Stev0 |
you'll probably need to richen it a touch as you'll have more oxygen as Rat said. I'd say go up a size on you pilot jet for a start. The CV design does compensate a little for but that will probably be more than it can handle. I used to run one size smaller pilot if I went up the tablelands for a while in summer. in winter the lower temp seemed to compensate enough. Have a read of this link. I wrote it for sporties but it applies in equally as well in this instance. http://xlforum.net/vbportal/forums/showthread.php? t=49078 | ||
| Kevmean |
Remember though that as well as the air being denser (heavier) that is being drawn into the intake the nearer sea level that also the air is denser by the same amount acting on the fuel in the float bowl .... this is why a good carburetor works so well in different air temp and elevations, denser the air the more pressure on the fuel in the carb as well as the air going into the engine. So the denser the air the more fuel that will flow through the same jet size to compensate. | ||
| Phaedrus91 |
So it took me a lot longer to get down to Texas then I was planning.. I took the cyclone down to DFW in a pickup so I didn't have to worry about jetting till I got there at least.. rode the bike for a few days down there.. with a 185 main 45 slow and no shim. (how the carb was set in NM) so I checked the plugs and they were nice and white so I rejetted to a 200 main, kept the 45 slow and added a washer that I measured out at .012 I put in some new champions (gapped to .050 (not sure how correct this gap is, I am running NRHS 1250 kit and a crane high output single fire coil) and ran the bike for a few miles.. mainly at about 3/4 throttle to test out the main jet.. the plugs look whitish yellow.. More shimming? I had a deceleration pop before jetting while at this altitude and it seems to me that the pop is worse now.. before it seemed that it only popped while rolling off heavy throttle and now it seems to pop if I bump it up to about 3000 and let go.. |
