The airfilter was just cleaned and re-oiled when i serviced it. No spark arrestor. It doesnt bog or backfire. Runs smooth, but there is no power band so to speak...its just flat. It accelerates smooth, but there is no oomph or kick to it when your on it. Feels more like a 400 class machine when you accelerate. Gas in the tank is fresh from the pump. Carb is spotless. I'm pretty familiar with atvs as i work on them for a living, but mostly Polaris (also work on mowers/powerequipment in summer months). But this has got me flustered[img]i/expressions/face-icon-small-disgusted.gif[/img] Thanks for the sugestions[img]i/expressions/face-icon-small-smile.gif[/img]

PS
Still curious as to what others are running for jetting with an HMF and K&N

 

Down south at sea level with the same mods as you except I have the Webcam and Diamond G racing snorkel, DJ-138 main, #38 Keihin pilot and clip on needle 4th notch from the top, mix screw 1 1/4 out. Didn't mean to insult your intell. Also did this all of a sudden start to act up?

 

No insult taken at all[img]i/expressions/face-icon-small-smile.gif[/img] DIdnt mean to sound snooty to ya if i did, lol[img]i/expressions/face-icon-small-smile.gif[/img]. When i intially put in the jet kit and filter i noticed a difference, felt pretty peppy. But that was probably 2.5 years ago. Put the pipe on it a few months after that and jetted to 128 (biggest in the DJ Kit). I then ordered a 130, 132, and 134 and put in the 132 to try. It never really seemed as peppy as i thought it should of. But i kinda thought it was ok. Never really bothered to try much else with it...havent ridden it that much in the pat year, been so busy and all. Driven a ton of sp500's and they always felt quicker than mine but never did a heads up run until last night with the 400. Scary part was that my mom was on that one trying it and i couldnt pull past her, lmao. Oh well. If i have a chance tonight i may try swapping jets again and see what it does. How do you like the Diamond G Snorkle? i've been thinking about ordering one...if i can get this straighted out. Seeing your at a 138, i would think the 130-132 would be in the range for mine..but i dunno, lol Thanks again for the input and help, its much apreicated!

 

The Dynojet instructions were pretty much right on for me before I added the snorkel and cam. Did you use their reccomendations for your elevation. If you are running rich that will rob a lot of power. Try a plug chop with a new plug at WOT and see what the plug looks like. The Diamond G was one of my best performance mods. Well worth the money. Them boys did their homework. I talked with them about it before I bought mine and they did a lot of R & D. It really lets a lot more air in at the right velocity which will in turn allow you to put some more gas to it (bigger main). Sounds like you are running rich.

 

i dont care what is going on you sould be able to take any stock sportsman up to the 600. maybe not with the auto but in stock form i will beat a sp600 with a filter and jet kit. given the other rider weighs 270 but im about 210.

 

Hey Guys,
I wonder when they'll start making a performance airbox lid like they do for some of the sport quads.
Wouldn't that be cool? YOu could prob make yourself one by buying those little round filter inserts
and drilling them yourself. Any thoughts?

I still have stock jetting so I can't add anything to the discussion.

 

the last thing i want to do to my air box is put holes in it, that would only increase your chances of sucking water. But if you really want to increase breathing just drill some holes in the lid, i just dont advise you do so.

 

If you guys want to increase airflow you should look at the Diamond G Racing snorkel. The company is out of California. Its basically a metal tube with a bevel on the end that slips right into the rubber connector on top of the airbox in place of the stock, restricted plastic snorkel. Those boys did their R & D. It let me step up to a # 138 Dynojet main.http://www.diamondgracing.com/catalo...67/1653596.htm

 

Oops, sorry guys. I mentioned that because I don't do that much mud riding on my Vinson. I like to do
agressive trail riding, etc. I just want to get the most acceleration, etc. performance out of mine.

I'm dying to try these clutch kits and other mod's you guys are talking about but I'm not sure if I should
wait untill my warranty is up first. I don't want to void it.

Thanks

 

Moto the Diamond G snorkel is not for mud riding. It leaves your air intake in the stock location. Just lets the engine pull a lot more air. I dont think it would void the warranty. Besides if you have to take it in for repairs take the machine back to stock.