| Author | Message | ||
     Lars |
Hey all, going on trip from New Hampshire to Montana via the Eisenhower Memorial Tunnel elev. 11,112 feet. Now, I'm going from maybe 600 ft. msl to over 11,000 ft. msl. I've got the regular CV carb with with Thunderslide etc. Wondering-half expecting some pretty significant difficulties (read: performance deterioration)when I start climbing above 5000 ft. msl. Would appreciate any help from those in the know. Lars | ||
| Chuck |
keep the rpm slightly higher than normal . . . and carry a couple of extra spark plugs for good luck. | ||
| Buelliedan |
Lars, You will definately need to rejet if you want the bike to run properly. I suggest you get in touch with Aaron about this since he lives at high altitude and is an expert about proper jets. | ||
| Aaron |
I guess I don't understand the question. Yes, the performance will be in the toilet. Figure 3% per 1000' if you're jetted correctly for the altitude, more if you're not. Not a whole lot you can do about it, short of forced induction. If you're jetted properly for sea level, you'll be pretty fat up there. The motor should still run, though. I agree with Chuck ... keep the plugs clean and have a couple spares. If per chance you should stop and let the motor cool, you might avoid the choke or excessive pumping on start-up. Good chance you'll flood it. But if you just keep going, you'll most likely be fine. Is that what you were looking for? AW | ||
| Lars |
OK, I am jetted fine for Sea Level. So, it would appear that just suck up the crappy performance and change the plugs out? Jeez, I'd thought it'd be more complicated. Just in case though, if I end up running too rich, what would you suggest for jets? Thanks, Lars | ||
| Aaron |
No, it's not complicated. The CV does a pretty good job of altitude compensating. I really doubt you'll have any trouble. Here at 5300', optimum summertime jetting in my one CV equipped bike (the S2) is a 180. I imagine that up there, it drops to a 170 or 175, I don't know, I've never tried to jet for up there. I wouldn't go any smaller than you have to, though, and I sure as hell wouldn't keep running the jet after you come down, you could toast the motor. I run that jet with an unshimmed N65C needle. I suspect, though, that you'll be fine. You *might* have some trouble if you head up Mt. Evans, though. AW | ||
| Lake_Bueller |
Lars - If you're just "passing through", you shouldn't have any problem with the elevation. I lived in Vail and ran a "sea level" jetted CV carb for the first three months. Probably not the best for the engine but no harm, no foul. Only problem was stopping for a photo op at over 12,000'. You'll definately want to carry an extra set of plugs (just in case). Good luck and enjoy the scenery!! It doesn't get much better. Mennis | ||
| Lars |
Aaron, thanks a lot. I do appreciate it. Hey Mennis, wanna have some lunch when I putt through the area? Lars | ||
| Blake |
Lars: I ran the stock jetting in my '97 M2 and did Trail Ridge Road (12,000+ FT) through Rocky Mountain National Park in Colorado (Aaron's back yard) with no problems. Keep your stock jets; as Aaron says, the risks associated with running too lean far outweigh a little richness for a brief stint in the mountains. | ||
| Suzypoozie |
Hi there, I just posted a question on another thread, and found this one. I also just wrote an email to Aaron. Sorry if I am coming across pushy or rude... Apologies out of the way, my bike is back firing quite a bit, and I am thinking it's a jet issue. I have a Forcewinder air filter on it, and am in Denver (5,280 elevation) from Portland (close to sea level). I haven't changed my jets yet. Do you think 180 is the way to go? Do you know of anything else that may cause this backfire issue? Someone suggested a bad O-ring on the exhaust. Thank you in advance! | ||
| Andrewb |
Hi Suzy, My S3 just started popping out the exhaust. I found the intake seals were shot, the rear was really toast. The worst part was I ran about 300 miles on the lean side, the lucky part is that Mobil 1 synthetic absolutely is the best oil ever to grace an engines internals. Good luck, Andrew |
