The stock Jet in any DS650 is a 165, Mikuni. a 190 mikuni sounds way too rich for the modifications that you have. If you plan to stay with the mikuni jets, get the 185, 180, 175, 170. Then start trying one jet size down till it runs better. When it seems like it is running good, test it out with a 2-3 hour ride, then check your plugs again, adjust accordingly. Try setting your air / fuel mixture screw between 2.5 and 3.0 turns out, that seems to be what everyone runs. (I have simple mods on my machine, and it is three turns out, stock is 2.5.)

 

dunescreaminmama,
If you and the huz can make any of our get-togethers (like 4SW) there are plenty of us that will let you take a test ride. They are only as mean as you want them to be although they seem to become meaner when Raptors show up [img]i/expressions/face-icon-small-confused.gif[/img] I just don't understand it. [img]i/expressions/face-icon-small-tongue.gif[/img]

Blackhawk, Cool
I bet the jet he got with the pipe is more like a dynajet in size but is still to big. I have a 170 (mikuni)with the same mods, a 170 or 175 mikuni would be plenty.

 

im thinking of buting a 170 main jet and #4 needle posetion and 3 turns in air/fuel screw and remove the top cover of the airbox and i have a complet pipe with k&n filter .


do you think it will work fine for drag racing and top speed and is thear a big difrance if i remove the airbox cover or leave it on ?

 

JSsDS

you sayed that you have the same mods. that i have on my atv so how it feel is thear a big difrance between the stock ds-650 compared to your ds and did you drag raced any other atv like banshee with mods. or rapter with mods also.

can you tell me what is your exacte setting for your ds and if i jet my atv does it going to damege the engine in the future .

 

Cooldevil,
My DS runs better every time I ride it. I put the pipe and K&N on and jetted it when it had 10 hours on it (in 2000). It never gave me a lick of proplem since...ever, not even a backfire. My plugs are mostly white with a hint of tan, so I know it jetted correctly.
I don't have the chance to drag much but when I do It runs with like equipped banshees, Raptors need not apply. On the hill it does very well for a stock motor. I am very happy with it.

My main is a 170, clip is stock (3rd pos) and I'm not sure where the needle is, i've adjusted a few times and never checked it. Personnally I think guys on this forum put too much emphisis on the needle position in regards to performance. Just set it so it idles good and leave it, you will never feel the difference that it makes over idle.
Hope this helps

 

Dune Screamin Mama,
The chart originally came from a friend of mine..Terry Campbell, Yamaha V max and Royal Star guru, He helped me out a lot, and when someone was asking about jet sizes, I posted a link..that is why it says Vmax comparison..Imagine that.....I don't know how it relates to carbs other than the stock V max ones, but when I searched, it was the only thing I could find..

..not meaning to start a gripe or anything, but I have seen folks use pages out of others sites without giving credit for where they got them from.. I think it would have been better to provide a link to the site that has it instead of making it native..but that is my opinion..

Just glad that the folks that need the info get it from somewhere..

and YES, Buttfungus did a real good job on his site..a lot of helpful stuff there for sure..

 

Surveyor....You are absolutely correct!!! this is the link that the information comes from....

carbs

If you check a number of my posts, I usually DO just post the whole link. I have no idea why I didn't this time, as not giving credit where credit is due is a pet peeve of mine also. I apologize.

Even though it is "Motorcycle Theory" the same carburetor basics apply. I was first directed to that site by my husband (dirtbike rider) who thought the charts would help me sort it out. For those (like me, who basically have the mechanical aptitude of a deer, but am trying to learn) who are just trying to figure out carburetion, it seems like such a helpful site. I use what seems to apply to get an idea for general settings and then fine tune according to whatever other information I can glean from these forums; although, I ride a 4-stroke, so the tuning isn't quite as "fine" as if I was trying to learn a 2-stroke.

I sure didn't mean to offend anyone...thanks for pointing that out to me Surveyor, so I could get it corrected!!!!

 

Surveyor,

Concerning your comments on giving credit, I agree. However, I strongly disagree about making only a link to a site with information on it, here is why: imagine if the information you are 'linking' to is extremely handy and valuable. Now imagine that web site going off line, for any one of a billion reasons. Now you're screwed, forever. However, if you copy the data, and recreate it on a web site in which you yourself have control, that puts you in the drivers seat, allowing you to know that without a doubt at all, you can and will always have that information available to you, and it will be available to your friends & the rest of the world as well. I've seen a lot of good information drop off of the internet, and by merely making a link; you are trusting someone else with data that affects you.

I'm not using Terry as an example (I assume his info is still online?) however I've watched other sites going offline for any number of reasons and all of the good data which was shared on them goes offline along with them. This whole philosophy goes right along with the theory: "If you want something done right, you had better do it yourself."

 

Blackhawk,
point made. Info is good to have, no matter where it comes from. no worries..or gripes...lets ride..
TCarizona's V Max site