thats interesting! I'd like to know if it works that way.

 

That's what a local ATV shop mechanic told me. He said it was derived from a road racing carburetor. Apparently the reason it's like that is so that when you give it sudden WOT the engine doesn't bog or try to die before it get's the right amount of gas and catches up. I'm sure it's not that simple but again I'm undergoing a big learning curve. I'm going to continue to research this modification of the slide spring. I saw something about this somewhere and I've just got to find it again. I would appreciate any dirt you/you guys can dig up on the subject also.

 

looks like its about time for me to take the carb apart and see whats goin on in there, was planing on doin a complete tear down anyway

 

Moto, it is easier to get the Dynojet kit for the carb. It comes with a new shorter spring to give you a quicker throttle response, a new adjustable needle jet with diff. taper needle, and an assortment of jets. You may or may not have to up the size of the pilot jet to a #38 Keihin. Yes the Vinson has a Keihin CVK36 carb, which is a vacuum slide, that works off of vacuum created by the velocity of the air that is sucked through throat of the carb., which is controlled by butterfly position, which is controlled by your thumb. Your pipe should have come with a Keihin #142 main jet, which is about the same as a #126 Dynojet. Let me know if I can help more.
The Dynojet kit only costs around $50.00. The Harley dealer usually has an asst. of Keihin jets because they run CVK carbs also.

 

Thanks Camo,
I'm trying to jet it with Kehin jets instead of the Dynojet stuff. It's not that I don't like Dynojet products (I've never used them) but it's the fact that my friend and local ATV shop mechanic will never let me live it down. He does all my ATV / Dirt bike work that I can't do and thinks that nothing works better than original Kehin/Mukini parts. I'm sure they're all great quality but I don't want to perterb him,...hence, I loose my mechanic who helps me all the time. You should have heard the bitching I got when I showed him the Diamond G Snorkel. LOL!

Anyways, I ordered my HMF (ONLY $211.00 Clams including quiet core and taxes) through him but it did not come with anything but the pipe, screen, hardware and the quiet core I ordered. So I'm starting from scratch with the jets. He's ordered me some larger jets. (One size larger pilot and an assortment of larger main's) However, he's not aware of the carb slide spring modification (which as you say comes with the Dynojet kit)....more like he prob just don't want to fool with it.

**I wonder if I could order the new shorter carb slide spring from Dynojet by it'self. Or, I wonder if I could modify or slip my stock spring a little bit. What do you think?

Also, I found your thread on Highlifter about the head port and polish. I wish somebody somewhere would reply to it with some info. I would love to do that to mine also.

Thanks for all your help. I'll bet that's a mean machine you've got there with all those mods.

 

Yeah you dont want to tick off your resources. I know HMF recommends a #142 Keihin with their pipe and a high flow filter. With the DG snorkel you will be able to increase it even more. The spring in the Dynojet kit was about a inch and a half shorter with a weaker tension also. Another, needed in my book, is the adjustable needle jet with the more aggressive taper. The Dynojet kit really helps you tune the engine a lot better. I am running a DJ138 main now, which is the same as a #152 Keihin. Let me know if you have problems tuning and I will find the links about the diff. circuits in the carb and how they affect performance. Nevermind, here it is

http://justkdx.dirtrider.net/carbtuning.html

 

Thanks Camo,
I'll prob end up picking up a DJ kit for it in the future anyway as I attempt to fine tune it. From what I've seen on the DJ
website I don't think you can buy these parts individually. I could be wrong and I'll keep looking. I'm scared to clip my
stock throttle spring. By the non response of other peope on this web site about this subject I'm assuming they either
didn't make the mod or just installed the spring supplied with the DJ kit. I guess I have to be the oddball for now.

BTW, is the stock needle even adjustable? I've got to get that part of the carb apart soon. My kehin jets are supposed to
be in tomorrow and I'll tackle putting everything back together over the weekend for sure. I'll let you know what happens.
I prob won't need a keihin #152 main since I'm still running the stock air filter. What do you think? Hmf w/Quiet Core,
DG snorkel, and stock air filter.......

 

The stock needle does not have notches for a c-clip like the DJ needle does but you can shim it. The stock needle is also is thicker. Moto, I thought you already had a high flow aftermarket filter? If not need to get one to let the extra amount of air into the engine for the DG snork and HMF. That stock filter is gonna restrict your flow bigtime. If you have a high flow filter, pipe, DG snorkel, you should be able to start with a #142 Keihin main. I hope I'm not confusing.

 

Hey Moto,
Oops, I haven't picked up a K&N for it yet so I'm going to have to jet it with the stock one this weekend. Hey, how could I shim the stock needle?

 

I am following that discussion closely, I dont have much input on the carb mod to add because the only thing I did was rejet it to a 140 keihin main. Althoug I can confirm that one I got my head machined 0.025" over, the torque difference was noticeable easily, now I can go through some rough parts on the trails without going into low gear, high gear has much more torque, and low is a beast! really helped my ATV pulls too.