DR650 Jet Recommendation for Varying Altitudes
 

Hi Guys,
I've been throwing feelers out over the web in regards to getting some guidance in prepping for a July departure around the world. Most notably I am trying to plan out my jetting so that I can transition from sea level to projected elevations of 10,000 feet or more. Presently I'm tuned for max power at sea level with a cut open air-box (as demonstrated by the Keintech website), K&N Filter, DynoJet 170 Main jet and Needle, FMF pipe, and Jesse Extended Mixture screw turned out 2.5 times. Runs extraordinary and color-tuning demonstrates perfect mixture at idle. Obviously this will be way too rich at altitude though. So I'm definitely going</span> to go back to the stock air box (cover the hole with a pre-shaped CD case and silicone around the periphery to seal), but as far as jets go the stock 140 main jet had an awful surging quality that the DynoJet kit fixed. If I drop down from the 170 to the DynoJet 150 main, would that be too little fuel to compensate for the K&N and more notably the FMF slip-on? Otherwise that seems to be the closest to stock set-up which is reported as great for up to 13,000 ft., yet without the surging that the stock Mikuni 140 main jet and needle produced. I'm happy to lose the max power I have now for better MPG's and to avoid roadside jet changes. Your guidance and experience would be very appreciated. Thanks.
-Remy

While it definitely sounds like you know a shade more than me on the subject, my experience with a DR650 at altitude was good.

We took 3 of them along the Pamir at up to 4600m, and were at least a week above 4000m. The two totally stock bikes idled and ran fine, but essentially had nothing beyond half throttle. We could just get them up to 100km/h. Riding slower gave no issues though.

One bike had a Staintune exhaust, stock airbox and unknown carb internals. It had zero issues, could pull to 100, and ran like normal... or possibly my girlfriend just never uses beyond half throttle anyway...

Ben

Jeeze, sounds way too complicated! I took my DR650E with staintune and stick carb up to 4,800m, it does struggle a bit at that altitude and you can only use the lower part of the throttle, but to be honest I wasn't really in a hurry and just took in the scenery while riding a bit slower.

I swore by this on my South America trip. My airbox has the top cut out. When riding from sea-level to 15,500 ft, I had a dj 155 main in and the dj needle three from the top. When I was at 10,000+ for a while (most of Peru and Bolivia), I put the stock jet and needle back in for better performance and mileage. I took it up to 19,060 ft in Bolivia with the stock jet and needle.

-Jeff

So Jeff, did you have the air box cut out as per Jesse at Kientech's example? I just covered that up to return the box to an approximate stock size snorkel hole figuring at altitude I can remove the side of the box and that will allow for a huge addition of air. Also, did you have the DJ needle at the normally recommended 4th from the top then switch to three during your journey, or did you start out at three from the top to begin with? Trying to reduce my jetting, rejetting, rejetting, rejetting...

My thoughts on DR650 jetting in a nutshell: The DJ needle 3 from the top, 155 main jet, air-fuel screw, and air-box cut as per jesse's instructions, will get you to 99.9% of the places on your trip. In other words, you will not have to pull over on the side of the road and change your jetting just to get to where you want to go on a daily basis.

For example, in Peru I went from 13,000+ to sea level in a couple hours with that setting.

With the DJ needle clip fourth from the top, I couldn't even go from sea-level to 5000ft, without pulling over on the side of the road to lean it out.

At sea-level, having the needle fourth from the top does run better, and the stock jetting runs better at 10,000+, but if you're constantly changing elevations, the clip 3 down and the 155 will work well. I'm not saying this is the only way, but it's what worked for me, and it kept things simple. I'm lazy, and although it is easy to change, I didn't want to do it daily, weekly, or even monthly, just to get a couple more hp at a given elevation.

If you're setting off on a RTW you have plenty of time to learn as you go as to what works for you. Jet and needle changes take 15 to 20 minutes on a DR, so I wouldn't worry about it too much, and it sounds like you already have the DJ kit to give you options. Change it as often as you please/feel necessary.

I'm obviously a little partial, but you went with a great bike! I don't know how many times I heard other bikers say they had gone with a DR650 as well.

Cheers,
Jeff