DynoJet for high-altitude: my experience (2009 KLX250S)
#1
06-27-2015, 04:21 PM
Join Date: Nov 2014
Location: New Mexico, USA
Posts: 80
DynoJet for high-altitude: my experience (2009 KLX250S)
2009 KLX250s, UNI air filter, snorkel removed, stock exhaust
Objectives: More power but stay quiet and mostly stock. Ability to go to higher altitudes.
Thought I would share some DynoJet results for higher altitudes. People get good results at different altitudes with all kinds of jet sizes
Table:
https://docs.google.com/spreadsheets...Dnc/edit#gid=0
so I called DynoJet and gave the representative a range of 4000 to 8000 ft, with most riding 6000 to 8000. I live at 5900 ft, go down to the 4000s in AZ in the winter and up to 13000+ in CO in August. Obviously I am going to have to do some rejetting but would like to minimize it.
The advice was use Stage 2. They did not see benefit of removing the air box cover in dyno testing of this model. (Note that a dyno does not measure subjective user experience, such as throttle response.)
Needle: 2nd groove from top
Screw = 2 to 2.5 turns out
Main = DJ116
For 13000 ft maybe go down to DJ112 but probably not worth it. Remove airbox cover at this high altitude? No it really will not help with a CV carb, unlike my old ‘82 XR200R where it literally would not move at 12500 with a 125 main and then blasted up to 13300 when I pulled the cover off.
DynoJet install. Followed the order on instruction sheet:
1. Diaphragm and needle: needle with clip on 2 down, two washers (I hope they stayed on top; not much protrudes from top of needle), DJ spring.
2. Mixture screw is outside and had already been uncovered by first owner. It was 2 turns out. I set it to 2.25 out.
3. Removed float bowl cover: screw damage showed this had been done by the first owner so I did not know what to expect. However, the jet was 118=stock. Put in DJ116 jet.
All of the above was pretty quick and easy. I used Japanese-standard (JIS) phillips screwdrivers. Not cheap but they really fit Japanese fasteners. Noticed that tip on a Rick Ramsey web page.
Reinstalled carb. Here are my detailed notes for next time I have to do this:
1. Lubricate the rear rubber manifold inside and out, and the front manifold inside, with ArmorAll (tip on KLX forum). This will make the carb slip in much easier.
2. Lower the carb into the frame and push it over to the left side to get some room for the rear manifold (air box hose) installation.
3. Check that both rear hose clamps are on, then lower the rear hose into the frame with the "U" notch to the rear top.
4. Shove the rear hose onto the airbox with the U notch and the tab lined up. Don't tighten any clamps yet.
5. Carefully turn the carb, lift it up slightly so the throttle cable clamp is slightly above the frame and then shove it into the rear hose. This is where the ArmorAll really helps because there is a lot of friction getting the carb past the lip of the hose then inside the hose.
6. Lower the carb so the throttle cable clamp is now down inside the frame. This requires shoving the carb back into the rear hose and using that for some free play. Make sure the wiring harness is not wrapped around the carb.
7. Now again push the carb rearward enough to get it to drop into the front manifold.
8. Check the three hose clamps to make sure they are centered on the hose and manifold, then tighten them.
9. Connect the throttle cables to holder and to the carb.
10. Take advantage of having the throttle apart to inject cable cleaner through the cables.
11. Reassemble the twist throttle housing.
From carb on bench to reinstalled took about 2 hrs, with care. Bike fired right up. Whew.
Results.
1. Test ride around neighborhood (5900 ft elev): Did not notice much difference, but it had been awhile since I had ridden the bike;
2. On Chamisoso (6600 ft elev) I noticed the bike would jump off small berms when I had it revved up and cranked the throttle. It has never done this before on these berms. I had tried many times.
3. On the trail (up to 7600 ft elev) after awhile it seemed like throttle response was improved and acceleration up steep climbs was noticeably improved.
4. A couple weeks later I rode up to 11062 ft. I could not notice any reduction in power. The bike still climbed like a tractor in first and second gear, which is where I spend 90% of my time.
Overall impression: Glad I did it.
Objectives: More power but stay quiet and mostly stock. Ability to go to higher altitudes.
Thought I would share some DynoJet results for higher altitudes. People get good results at different altitudes with all kinds of jet sizes
Table:
https://docs.google.com/spreadsheets...Dnc/edit#gid=0
so I called DynoJet and gave the representative a range of 4000 to 8000 ft, with most riding 6000 to 8000. I live at 5900 ft, go down to the 4000s in AZ in the winter and up to 13000+ in CO in August. Obviously I am going to have to do some rejetting but would like to minimize it.
The advice was use Stage 2. They did not see benefit of removing the air box cover in dyno testing of this model. (Note that a dyno does not measure subjective user experience, such as throttle response.)
Needle: 2nd groove from top
Screw = 2 to 2.5 turns out
Main = DJ116
For 13000 ft maybe go down to DJ112 but probably not worth it. Remove airbox cover at this high altitude? No it really will not help with a CV carb, unlike my old ‘82 XR200R where it literally would not move at 12500 with a 125 main and then blasted up to 13300 when I pulled the cover off.
DynoJet install. Followed the order on instruction sheet:
1. Diaphragm and needle: needle with clip on 2 down, two washers (I hope they stayed on top; not much protrudes from top of needle), DJ spring.
2. Mixture screw is outside and had already been uncovered by first owner. It was 2 turns out. I set it to 2.25 out.
3. Removed float bowl cover: screw damage showed this had been done by the first owner so I did not know what to expect. However, the jet was 118=stock. Put in DJ116 jet.
All of the above was pretty quick and easy. I used Japanese-standard (JIS) phillips screwdrivers. Not cheap but they really fit Japanese fasteners. Noticed that tip on a Rick Ramsey web page.
Reinstalled carb. Here are my detailed notes for next time I have to do this:
1. Lubricate the rear rubber manifold inside and out, and the front manifold inside, with ArmorAll (tip on KLX forum). This will make the carb slip in much easier.
2. Lower the carb into the frame and push it over to the left side to get some room for the rear manifold (air box hose) installation.
3. Check that both rear hose clamps are on, then lower the rear hose into the frame with the "U" notch to the rear top.
4. Shove the rear hose onto the airbox with the U notch and the tab lined up. Don't tighten any clamps yet.
5. Carefully turn the carb, lift it up slightly so the throttle cable clamp is slightly above the frame and then shove it into the rear hose. This is where the ArmorAll really helps because there is a lot of friction getting the carb past the lip of the hose then inside the hose.
6. Lower the carb so the throttle cable clamp is now down inside the frame. This requires shoving the carb back into the rear hose and using that for some free play. Make sure the wiring harness is not wrapped around the carb.
7. Now again push the carb rearward enough to get it to drop into the front manifold.
8. Check the three hose clamps to make sure they are centered on the hose and manifold, then tighten them.
9. Connect the throttle cables to holder and to the carb.
10. Take advantage of having the throttle apart to inject cable cleaner through the cables.
11. Reassemble the twist throttle housing.
From carb on bench to reinstalled took about 2 hrs, with care. Bike fired right up. Whew.
Results.
1. Test ride around neighborhood (5900 ft elev): Did not notice much difference, but it had been awhile since I had ridden the bike;
2. On Chamisoso (6600 ft elev) I noticed the bike would jump off small berms when I had it revved up and cranked the throttle. It has never done this before on these berms. I had tried many times.
3. On the trail (up to 7600 ft elev) after awhile it seemed like throttle response was improved and acceleration up steep climbs was noticeably improved.
4. A couple weeks later I rode up to 11062 ft. I could not notice any reduction in power. The bike still climbed like a tractor in first and second gear, which is where I spend 90% of my time.
Overall impression: Glad I did it.
Last edited by KawaBiker; 06-27-2015 at 04:25 PM.
#2
06-27-2015, 06:04 PM
DynoJet used a KLX with stock exhaust to develop the kit - so that is all they know..
As they found out, you cannot remove the lid with stock exhaust. But I don't think you can get anywhere near 22-23hp with it on..
As they found out, you cannot remove the lid with stock exhaust. But I don't think you can get anywhere near 22-23hp with it on..
Last edited by Klxster; 06-29-2015 at 08:38 PM.
#4
08-18-2015, 08:06 PM
High altitude set-up
KawaBiker,
I'm at 4200' and I'd like to confirm I have the same set-up: Dynajet, Stage II, stock muffler, snorkle removed, but airbox lid on. Mine runs like a top from the 4k to 6k range that I do most of my riding in. Normally don't go over 10k. MPG equals 59 best - a mixture of trails and highway.
I'm at 4200' and I'd like to confirm I have the same set-up: Dynajet, Stage II, stock muffler, snorkle removed, but airbox lid on. Mine runs like a top from the 4k to 6k range that I do most of my riding in. Normally don't go over 10k. MPG equals 59 best - a mixture of trails and highway.
#5
08-20-2015, 01:59 AM
Join Date: Nov 2014
Location: New Mexico, USA
Posts: 80
Richard, yes that is my setup. I typically get 32 mpg because most of my riding is in first and second gear. I carry an extra gallon in a Rotopax and have to use it sometimes.
Last edited by KawaBiker; 08-31-2015 at 10:13 PM.
#6
11-08-2015, 03:46 PM
Join Date: Nov 2014
Location: New Mexico, USA
Posts: 80
Low-altitude configuration: 1500 to 6000 feet elevation
With snow in the high country I am planning to go as low as 1500 around Phoenix and lots of riding below 6000.
Still stock exhaust, snorkel removed, airbox cover on: DJ Stage 2.
I called up DynoJet and got the following recommendations:
Range of 1500 to 6000, with most around 4000 feet
Main jet = DJ120 (equal to Keihin 128, stock is Keihin 118)
3rd groove from top of DJ needle
Screw out from 2.5 to 3. I set to 2.75
Was easier this time. Turned the carb and did not remove the rear hose to the airbox. Again used a JIS screwdriver to avoid messing up screws. See this post:
Not all "Phillips" screws are the same: JIS | Adventure Rider
Checked the tiny fuel filter at the carb, just inside the fitting: clean.
The fuel lines all look good but I will replace all of them in fall 2016: will be about 7 yrs old. Will use 1/4-inch ID good quality fuel line: the OEM prices are ridiculous.
Test ride around the neighborhood at 6000 feet: good power!
Still stock exhaust, snorkel removed, airbox cover on: DJ Stage 2.
I called up DynoJet and got the following recommendations:
Range of 1500 to 6000, with most around 4000 feet
Main jet = DJ120 (equal to Keihin 128, stock is Keihin 118)
3rd groove from top of DJ needle
Screw out from 2.5 to 3. I set to 2.75
Was easier this time. Turned the carb and did not remove the rear hose to the airbox. Again used a JIS screwdriver to avoid messing up screws. See this post:
Not all "Phillips" screws are the same: JIS | Adventure Rider
Checked the tiny fuel filter at the carb, just inside the fitting: clean.
The fuel lines all look good but I will replace all of them in fall 2016: will be about 7 yrs old. Will use 1/4-inch ID good quality fuel line: the OEM prices are ridiculous.
Test ride around the neighborhood at 6000 feet: good power!
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