Rock solid has nothing to do with it.
As you've seen in above posts, in S. America you WILL spend months above 8000 ft. Quito is about 9000 ft., Cuzco about 8 or 9K ft. La Paz is over 12,000 ft. Many of the Alti-plano roads go over 14,000 ft. and many stay up at 10,000 and above for hundreds of miles.

But not to worry. This is not nearly as daunting as it may sound. If you jet your bike to run very lean at sea level (stock settings are very lean) with the air box closed up and snorkels all on, then a very easy solution when over about 7000 ft. is to begin opening up the air box. Over 10K ft. open it up all the way. This will make a huge difference and essentially leans things out. You could also do as suggested and lower the needle to lean out the mixture also, or change main jet.

Just don't forget to put it all back when you drop back to near sea level. I would bring a variety of jets along, as you could always install a smaller (leaner) main jet when in the Andes. But most times opening the air box takes minutes, whereas changing the main jet is more work/time. So keep this in mind as a "quick fix" when up very high. It will help.

There is really no danger in running too rich at high altitude but running too lean at sea level can ruin your engine, so be aware of your jetting and pay attention to altitudes. Altering air flow is easier than changing jets and may be enough to allow the bike to run OK up high. It will lose power, but not nearly as much if you did nothing.


Also, some jetting and internal combustion basics here:
Mark:
All engines lose power at altitude. ALL. With F.I. the difference is your mixture will remain consistent as the F.I's altimeter sensor adjusts fueling for altitude in conjunction with many other sensor input. The ECM then calculates proper fuel/air ratio, adjusts timing et al. But you still lose power and even fuel economy goes down, yes even on F.I machines. Less Oxygen means less efficient combustion, means less power and more fuel used. Basic.

Mark, your KLR starts out with just 37 HP. At 12,000 ft. that drops down to about 30 HP. The Vstrom 650 starts out with about 67 HP, drops to probably 55 up high. Still far more than a KLR.

If your bike is so down on power and getting poor fuel economy you need to re-jet, open air box up, adjust your Fuel/Air screw much leaner. This should really help a lot. Your air cleaner will get dirty sooner with air box open but the bike will run like a new bike. Will start and will idle better. Plugs will not be black, and MPG will improve by at least 25%. Don't be afraid to mess with your carb. Get help doing it but do it!

I wasn't aware that F.I. engines also lose power, but it makes perfect sense. Hadn't thought about opening my airbox either--an easy partial accommodation. I'll try that next time I gain significant altitude. I'm reluctant to do anything more since, as you said, I'm not hurting anything by doing nothing. Jetting for altitude is fine as long as you're at altitude, but I need this bike to run another good bit without engine work...and I'd be just the one to drop down to sea level with changing my jets back.

Yes, all bikes responds on changing in altitude. Both for mixture reasons (not FI) and the fact that your engine will get less oxygen. The lack of oxygen is more or less the same as reduced cylinder-volume and there is nothing you can do to eliminate the loss.

As a rough guide you loose 10% power per 1000m (3000 ft) but many factors kicks in.

If you start to mess with your carb-settings it's important to know how your carbs work.
This is a bit different from carb to carb but generally the main-jet doesn't mean much before you have 3/4 throttle. The mixture-screw is only in effect at low throttle (typical up to 1/5 throttle).

How often do you drive above 3/4 throttle or below 1/5 throttle? Not much, I guess. Your idle will drop at high altitude but IMHO it's better to increase idle a bit then to adjust the mixture.
But of course if you drive with the throttle fully open most of the time changing the main-jet will help.






If you want to change something it is usually better to change the clip-position because it usually has bigger influence in the normally used throttle positions - on my bike clip-position makes a difference up to 3/4 throttle.
When I travel I normally just adjust the idle and live with the fat mixture, it's not that much power to gain with adjusting and I can live with the reduced range.

As other have mentioned it might be possible to open up the air-filter to get a leaner mixture. This works on some bikes and not so well on others. If you have a bike with a CV-carb it typically changes the sound of the engine so people think it runs better.
Another issue is that when you open the air-filter more dirt might pass it.

If you mess with the mixture it's extremely important to get it back before you return to low altitude, otherwise you can seriously damage your engine (melted pistons etc).
This is one of the reasons why I prefer to adjust idle instead of mixture. If you forget to adjust it when altitude drops the only thing that happens is that you have a high idle.

When it comes to the KLR it's a bike you seldom see in Europe, Asia or Africa but a lot of people have used it and the weak spots should be known. Personally I prefer airheads.

Great comments!

It's true, on a carb the needle clip position is the most important and most of your riding will be "on the needle". Problem is, I don't think a stock KLR has an adjustable needle. (anyone know for sure?) Like so many bikes, there are no clip adjustments. In the USA this is a EPA thing. They set it as lean as possible and use a very lean needle taper to give low emissions.

This is another good reason to go to an aftermarket needle that does provide needle clip position changes. It's been too long since I've been inside a KLR carb, can't recall for sure, but I'm thinking its a fixed needle?
So NO adjustment possible.

Doing this sort of work also depends on access and how easy or hard it is to get too the carb. It's true, main jet changes only affect from 3/4 throttle to full throttle, so it is not so important. Nonetheless, I've found going to a smaller jet somehow helps the bike at altitude. I have no explanation for this, but it worked pretty well.

But more important would be the fuel/air screw and air box opening.
Dirty filters, as I said before, need to be looked after and kept clean.

Othalan ... didn't see any mention of the Suzuki DR.

I prefer the DR to the KLR. I rode an '02 KLR thru South America, and a DR thru Africa. The DR wins hands down --- lighter, faster, funner, more maneuverable, way better offroad and equivalent on the highway.

I'll continue my RTW in a year or two thru Africa again and into the Himalayas and it will be on the DR, no question about it. Good luck ~~

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I will then have a guitar strapped across the top along with the tent. Yes, I know the standard warnings about instruments.....


Consider buying one of the travel guitars that you sometime see in music stores. I ve seen them every once in a while. Half the size of normal ones. Use pig nose type amp to play.

Great information, thanks!

The KLR can be easily modified for adjustable idle fuel/air mix and slightly less easily modified for an adjustable needle. Sounds like it might be worth looking into both.

I've heard lots of good things about the DR, but never quite found a reason to dump the KLR for one. Perhaps someday I have spare time & money I'll farkle one up and see if it grows on me.

I have a carbon fiber travel guitar that has traveled almost as many miles by motorcycle as I have. Not quite as small as other travel guitars, but far more sturdy and sounds better.

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I'm hardly decided on the KLR....in fact my obsessive-compulsive planning nature makes me ever less certain (as a side note, that obsessive-compulsiveness tends to disappear once I'm on the road). Of course I'm just as uncertain that any other motorcycle would be the best one for the task.

I suppose what really sends me towards the KLR is that I don't really care about its lack of power. I won't be in a race against time, nor will I have a schedule to meet. I will simply have a bank account I'm prepared to drain and the next adventure to meet. If the KLR leads me to travel slower and meet more interesting people ... well, I'm not certain that is a drawback.

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Traveling The World Since: 2011
Blog: The Seductive Life (General Travel)

Since you will spend the majorty of your time on pavement and make cameo appearances off pavement, a K75c would work well. Its just as heavy as any BMW GS...and infinitely more reliable and easy to work on.
Just make sure you swap out the final drive with something repaired by Bruno before you go...

I did a bit of off-roading on the K and it survived fine. So its a valid option.

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edde
93 BMW K75s
www.motoedde.com

This is a great attitude! You're gonna have a fantastic trip! I hope you find some good ways to pack your guitar. Opens a lot of doors and makes people smile everywhere you go.

Have a good one