pilot jets

[Nails]

Is there some general consensus on what the pilot jets should be, for low elevations?
I'm getting the bike ready for a long ride in July, including lots of stuff like fixing a bashed header. I cleaned the carbs and plan to synch them. I have 108/38 jets, evidently stock -- I thought it might be the high elevation kit (Colorado bike).
I drilled out the p-j plugs. The problem is that I want to tune it for low elevations, but I live at 7800 feet. I'll take tools to set the pilot jets right, but hope to find some general consensus (among you flat-landers) as a starting point. Literally: I'll start riding with that setting, and adjust it when I get down the hill. I'm sure it won't be any worse than the factory setting.
2 1/4 turns out?

[Mr Jensee]

Nails the Voyager XII has constant velocity carbs on her. Designed to self adjust fuel flow for all elevations. You shouldn't need to change any jets out for better performance in high elevations. I've never had to adjust them but send an email to Carl Leo because he knows the settings for the carbs.

[Nails]

With respect, that's only partly true. Kawa offered a high-altitude option with smaller jets. As I recall, they offer lots of other jets, evidently to support the large community that races their XIIs.

"Constant velocity" is sometimes called "constant depression", which pretty well sums up my experiences with other CV carbs at 7800 feet.

I agree that these are tolerant of high altitude. At least mine seemed to do well, given all the other problems like being filthy and badly out of synch. I think it helps that these carbs are so small. I didn't find much literature about these particular Keihins, but this article seemed especially informative: http://gadgetsfixit.com/articles/mainte ... carburator. (Let me know if I didn't type that right.)

Setting the main and pilot jets aside, I'm just trying to guess the pilot screw before synching them. I don't think changing it would mess with the synch much, but just trying to do the best I can. I'll carry a pilot screw driver, but don't want to tote the synch gages. I'll go for 2 turns out and see how it does -- other sources said to start there for other Keihins. (Big KLR crowd, btw.)

[Mr Jensee]

My suggestion is to shoot an email to the guru Carl Leo and ask him. If anyone knows the answer it will be Carl. And I don't think the carbs are too small. The engineers figure what size carburation fits a particular bike. The Voyager isn't a drag bike, it was designed to have enough power and at the same time not expend a great amount of fuel doing it. Yes you could probably put larger carbs on it but what are you giving up doing so? At 7800 ft. are you living on top of a mountain? Even Denver is only a mile high.

[Nails]

I said the carbs are small, not too small. I have another bike with an undersize CV carb, and it has great low-end snap. (That bike is single cylinder but two carbs. It has a secondary side-draft carb that begins to open about half throttle to give more high-end flow. That secondary carb doesn't even have an idle circuit. Odd, PITA to tune, but it works great.)
I notice few other bikes with Keihins that are as small as ours. One is a Honda 250/4! It's designed to run about 15K RPM.
Horses for courses.
I'll post how all of this comes together.

[ghostler]

Each cylinder is 18 cubic inches, so I don't think the carbs need to be big. In one magazine article, the stock XII did the 1/4 mile in 12.6 seconds.

This past weekend, at around 8,000 feet, I noticed my 2001 XII throttle was pegged going up a steep incline on I-25 south near Santa Fe doing 75 mph. I've got the low elevation jets installed in mine. CV carbs may do a better job than standards in elevation, but I think there are limitations, otherwise Kawasaki wouldn't have a high elevation kit. A computer controlled carburetor or fuel injection system would be the better way to go, as those auto-compensate.

Only reason why I haven't installed high elevation jets in mine yet is I live at 4,300 feet elevation and trek to lower elevations, too. If I had the high elevation kit, then would run leaner and hotter at sea level, something not desirable in a bike.

[Thud300]

At 7800 ft. are you living on top of a mountain? Even Denver is only a mile high.

The high desert in New Mexico is about that altitude. Spent a few days in Albuquerque, and me living at 650 ft, I could tell the difference, especially with physical exertion.

[ghostler]

Albuquerque is same as Denver, 5,000 ft elevation. Gallup, Grants and Moriarty are 6,500 feet, but Gallup hospital area (affectionately known as "snob hill" by the locals ) is 7,000 ft. Nearby Fort Defiance on Navajo Reservation is 7,000 feet. Chama that I was at this weekend is at 7,900 ft. I-40 at Continental Divide is 7,300 ft. I-40 Tijeras Pass east of Albuquerque is 7,000 ft. Cloudcroft near Ruidoso and Alamogordo is 8,700 ft. So, depending on where you're traveling in NM you can get to 8,000 ft elevations OTR.
Lowest in NM (i.e., Carlsbad, 3,300 ft) is south of us, but we have people living at the 8,000 ft elevations, too.

[Mr Jensee]

Living on the coast, I get nose bleed in a ten story building.