high altitude

[GaryLee]

I have 98 valkyrie do I have to adjust my carbs to run in the Rocky mountains?  I am from WI .  On my run I plan on going thru some passes that are about 10,000 feet above sea level.  I would appreciate any advice

[Hoser]

I did not see anyone who had any problems during the Inzane in Colorado a few years back.  I did'nt have any problem with mine going over Loveland Pass at 11,000 feet.  Hoser

[Bighead]

I rode coast to coast last year so I went through all types of elevation from below sea level to mountain peaks out west with no trouble. Gas mileage does vary though.

[Joe Hummer]

Hey Gary,

My opinion...you don't need to re-adjust your carbs for high altitude riding when you are only going to be riding around for a few days.  You will notice the bike will be down on power and you may need to downshift to climb grades and your gas mileage will suffer a little.  

I have had my bike to 10,000 - 12,000 feet and have only noticed what I mentioned above.  

Joe

[BonS]

In general you'll lose 1 hp per 1000' of elevation. At 10-12,000 feet you'll be down 10-12% so you'll feel it but Valkyries have plenty of power and will roam the Rockies two-up, with a trailer, with power to spare.

[salty1]

I've run my girl up to 10000+ feet, or close to it, a number of times and have never experienced any problems. IMO if your carbs are in good working order with the pilots at 2 1/4 turns out or less, no problem. If you lived at those elevations, you would want to lean out your fuel mixture.

[Brewer]

Our tour of SW Colorado crossed several passes.... none of the riders did any adjustments. roll the throttle a little more and enjoy the ride.

[Tailgate Tommy]

Our tour of SW Colorado crossed several passes.... none of the riders did any adjustments. roll the throttle a little more and enjoy the ride.

+1 buddy!

[Attic Rat]

Just ride your bike in Colorado and enjoy it. In the higher areas you will notice a loss of power do to the air being thin which causes a rich condition. It is not worth resetting the carbs for no longer than you are going to be there.

[Ricky-D]

Being that the carburetors on the Valkyrie are "constant velocity" carburetors,

at the higher altitudes the carburetors self-adjust and there is no additional

richness with the operating carburetors.

The slides are not raised as much as when operating at lower altitudes, and

thusly the needle is not raised likewise resulting in a leaner condition of operation

matching the conditions for that particular altitude.

***

[Skinhead]

The real power loss at altitude is the result of lower barometric pressure, at sea level baro is ~100 kPa, at the top of Loveland Pass it is about 63 kPa.  This means that WOT (Wide Open Throttle) at the top of LP feels like 63% throttle at sea level.  A/F ratio may be off from optimal, but that changes your emissions more than it affects performance.  The real hit is from available MAP (Manifold Absolute Pressure) which is equal to BARO at WOT.

[F6Dave]

A service manual I read several years ago said you lose about 3% of power per 1000 feet of elevation.  I've seen that same figure in other places.

Living in Colorado at 6700', I've become accustomed to the power loss.  I do notice the even greater loss when I ride over the higher (12,000' or so) passes.  Since the lowest point in Colorado is about 3300' in elevation, residents here get used to having less power.  BTW, our high altitude is why they sell 85 octane fuel here as opposed to the 87 you get elsewhere.

What I do notice (and like) is the very noticeable increase when I ride out of state to lower altitudes.  When my '98 Tourer was new I was amazed at how much harder it could accelerate when I rode near sea level.

[Skinhead]

A service manual I read several years ago said you lose about 3% of power per 1000 feet of elevation.  I've seen that same figure in other places.

Living in Colorado at 6700', I've become accustomed to the power loss.  I do notice the even greater loss when I ride over the higher (12,000' or so) passes.  Since the lowest point in Colorado is about 3300' in elevation, residents here get used to having less power.  BTW, our high altitude is why they sell 85 octane fuel here as opposed to the 87 you get elsewhere.

What I do notice (and like) is the very noticeable increase when I ride out of state to lower altitudes.  When my '98 Tourer was new I was amazed at how much harder it could accelerate when I rode near sea level.

That is true, we do a lot of vehicle testing in Fricso/Dillon/Loveland area.  The reason for the 3% loss per 1000ft is that the BARO decreases about 3 kPa/per 1000 ft increase in altitude.  If BARO at sea level is 100 kPa, 3 kPa is 3% of 100.  at 12000 ft, 3x12 is 36, so BARO at 12000ft would be about 100-36=64 kPa.  Love land pass is about 12000 ft so the BARO at Loveland Pass is about 64 Kpa.

[Windrider]

I have a 6 degree timing wheel on my 2000 tourer.  Any problems at altitude associated with that set up? Otherwise, all else is stock on my motor. I live at 1250 feet above sea level. I usually run 91 or 92 octane gas with no ethanol.  Thanks to all for the good comments on this topic!

[Bighead]

I have a 6 degree timing wheel on my 2000 tourer.  Any problems at altitude associated with that set up? Otherwise, all else is stock on my motor. I live at 1250 feet above sea level. I usually run 91 or 92 octane gas with no ethanol.  Thanks to all for the good comments on this topic!

NO

[moodyvalk]

Being that the carburetors on the Valkyrie are "constant velocity" carburetors,

at the higher altitudes the carburetors self-adjust and there is no additional

richness with the operating carburetors.

The slides are not raised as much as when operating at lower altitudes, and

thusly the needle is not raised likewise resulting in a leaner condition of operation

matching the conditions for that particular altitude.

***

Dude!?!? Do you make up everything you say?????  Facts are facts.... "constant velocity" also know as "variable venturi" works by means of pressure differential caused by the butterfly opening causing a decrease in pressure over the main jet/venturi, in a naturally aspirated engine this would be what most people know as vacuum.  Looks like some someone has never heard of "Bernoulli's Principle", which is the principle of how carburetors work..."Ricky-D's Principle" is how they do NOT work.  If you don't believe me just grab my son's 5th grade science book and read your heart out. 

there will be approx. 20% power loss at 6500 foot versus sea level... it will run richer than it is used to but you probably wont notice it.  when I took the "turbo Valkyrie" to colorado springs (6500 ft) on the air fuel monitor it dropped to 10:1 from 12.5:1 at about 1000 ft, that is a quit a bit more fuel that I had to tune out.  Although, normal cruising didnt seem too bad on the stock 35 slow jets....

just ride it and have a blast, nothing for you to worry about