Can I ask hands here... on how many different DS you worked with and what mods have you tried. Then please tell me on how many raptor, TLZ400's, 400EX's, and YFZ450's you have worked on.

Now I have done all of them, on the dyno and with all the mods you can think about. I don't need to ride a DS to know how that thing works. It shares the same make CV carb than the LTZ's, raptors and Predators. Maybe when you work on other quads except a DS you might learn something from the other guys.

Then on top of that I chat to the guys that won the Paris to Dakar race last year on a DS. I learned a lot from them and they themselves are using some of the tips coming from me and the guys we ride with. The also run a full race team with about 6 riders, all with DS's, so I believe they tend to know what they are talking about.

Keep changing your needle and have fun since there are some people that just don’t see past their own believes.

Don't believe me. Do a little search on carb tuning.

All of them will tell you the same thing as I am telling you now. Main jet 1st, then needle. Needle is not changed if you change altitude. Dynojet recommends changing the needle to the 3rd clip for the stage 3 setup, meaning changing it from the 2nd clip to the 3rd if you remove the airbox completely. Once changed and you are set on a stage 1 or stage 3 setup, you DON'T change needle when you change altitude. Read the dynojet instructions in the right context. Why, because you never fix the full throttle mixture by changing needles! In changing the main, you are also fixing midrange, exactly where the problem with this DS is. In other words if you still don’t get the picture. The area the main jet works overlap most of the needle jet working area, PLUS ¾ onwards. ¾ onwards the needle has no effect. So fix the whole range by changing the main, not the needle that fix part of the problem area.

Then the guys that prefer running the 14.7:1 mixture needs to change mains when they go to the coast. Guys running the 12.7:1 ratio has a very good chance that they will not need to change the jetting and very few do change it. They also don’t change jets for summer and winter. It works all year long. Now, added we don’t have snow here, so when it gets very cold, the jetting might have to be looked at gain.

 

bombardier does not change the jet when going to 3500 ft. They only recommend moving the needle. What do they know? Do you (freez) have any pictures with some of these famous riders have as friends. I am sure we would all love to see them.

By the way I am not saying that with enough changes (mods or elevation) the main jet should not be changed. I am jsut saying that with camds650's set up he needs to adjust the needle not the main jet. I also stand firm that with small elevation changes the needle is all you need to adjust.

 

Crackerjack - Haven't been keeping up much lately - work is busy.

Can you post a new thread about the new KMS EFI. Sounds like a sweet set-up.

I'll have to give you a call here to talk about it.

If you get boared on your drive to Glamis, give me a call. I'll try to keep you awake for a streatch or two.

 

Well, you asked for pictures.

Here is one of the guys I ride with and also is part of this forum. He is also the editor for the mag I write technical articles for. He is running a 03 Baja X with no lid, dynojet kit and Yoshi slip-on system.

Baja X at roof of Africa

The rest of the pictures are from the SpeedQaud shop that is running the SpeedQuad race team. The guy that did the Paris to Dakar race was not part of the race this year, as he was doing the BAJA at your side of the world. This team sponsored a French rider this year and he came second in the race. Most of the DS’s run Ron wood Pipes and some even the Ron Wood pistons and cams.

pic 1
Pic 2
pic 3
Pic 4
Pic 5
Pic 6
Pic 7
Pic 8, DS showing some YFZ450's how to corner.

I am not a personal friend with the Speed Quad riders, but I know the mechanic that set thier DS's up. Have had long chat with him and so does the rest of the guys on our group that ride DS's.

Guys. The moving of the needle will very likely fix the problem, maybe even replacing it with the stock one will help, but I am still saying that you can also fix the problem with the main jet.

I have explained this that from 1/4 to 1/2 to 3/4 the needle effect the fuel mixture. Now the main jet has some effect at 1/4 to 1/2, more effect between 1/2, 3/4 and full throttle. Now if you look at it, the main jet changes the fuel ration over much of the range of the needle. The two work together to get the final mixture. So you can change either one to fix midrange, but changing the main jet will have a wider effect on the mixture right across the RPM range.

Now there is something that might mess up the mixture or both the needle and main jet, and we have not checked to see if this is right. I have seen very few posts on the net about the right float height of the DS. If you take a clear tube and attach that to the drain hole of the float bowl, you can check the float level. This takes a few seconds and nothing needs to be removed.

To start get a clear tube about 1 feet long. The length does not really matter, so long as it can be attached to the float bowl drain and if you point it upwards it must be higher than the top of the carb. Now when you have the pipe connected to the drain hole, open the fuel delivery to the carb and also open the drain screw. This will cause fuel to run into the pipe and settles at a specific level. Tap the pipe to remove all bubbles from the fuel and then see where the fuel level is, compared to the mating surface of the float bowl and carb. With the pipe pressed against the carb, the fuel level should be EXCATLY 1.5 mm above the split. If it is higher or lower it is wrong. Higher than 1.5mm will cause a richer mixture and will cause the needle and main jet to work incorrectly. Drop the fuel level to the 1.5 mm split and check the running of the quad again. Maybe this is why the dynojet needle does not work. Most DS's will have about 3mm above the split and will cause slightly richer conditions

PS, fixing the float level to the right height on a raptor and it adds 3HP more to the top. It’s a setting you have to get right before you do anything else on the carb. Without it, everything is wrong.

O and lastly, this is not a setting you will find in any Bomb manual. This little test was provided with the predator manual. The predator uses the exact same carb as the DS. The Predator manual also explain the working of this carb much better than anything I have come across from Yamaha, Suzuki, Kawasaki, Honda or Bomb.

Lastly. I am a big Dynojet fan, but the DS’s in our group is not running the recommendations as per Dynojet. Needle positions yes, but they all run larger main jets, compared to the dynojet recommendation. In actual fact they run a setting recommended for sea level, instead of the 5000Ft recommendation. So, although I am a big fan, I don’t always follow their rules.

 

Problem fixed, Stock Bombardier needle on the forth clip (2nd from the bottom) and a 180 DJ main jet, mixture screw three turns out [img]i/expressions/face-icon-small-smile.gif[/img] crackerJack recommended this setting.


Thanks