Going to the bigger carb will really help. I piped my 90 and using a drill index opened the main jet up on the stock 16mm carb a little at a time and got it back on its feet. After that I went to a 24mm Kiehin carb and man what a difference. The Kiehin uses Mikuni jets which are easy to find and and comes with 2 jets. Mine was dead on out of the box (first for me). Definetly get the clutch springs and weights in the CVT and it'll really move. I have the 1500 in mine right now and it works great for dirt light sand. Took it out to the dunes this last weekend and it didn't have all its power in the soft sand, so I think I'm going to run the 2000 rpm in the soft sand.

 

Those paddle tires can be hard to get rolling. Mine digs like crazy after the 53mm kit.

 

do you have the stock air filter. If you do, change to some type of k&n or uni-filter...your gonna need more air coming in.. My guess your way lean on your main (thats not good)..Tuning carbs for aftermarket intake/exhaust is time consuming..It just takes a little time. I can go in detail and tell you how to do a plug chop if you want, this will tell you which circuit on the carb is off.

 

Raptorlegs,

Thanks for you replies as well as everyone whos tossed in their opinions. Obvious Billy at WRH is the go to man if I decide to fix up the quad. After all its a chinese made 2000 yerf dog 90 and after a pipe and CDI $500 from miniquadracing. How much more would I need to make this quad rip through sand? IM a little confused though since you talk about 20mm kit due to easy tuning, but went with a 53mm and now your plowing through sand. Again it is a custom pipe with expansion chamber and I have to order new clutch springs, sounds like 2000 rpm is the way to go. I will be ordering everything from now on at WRH. But how about installing a 110 kit before I start with carbs and uni air filter?

 

sssduane,

Thanks for you input. sounds like your 90 is in sand a bit. I'll talk to Billy about getting 2000rpm springs but I believe your dinli 90 is chinese made also so the 24mm kit worked out of the box? By reading other replies to my question, some people have gone way up to a 53mm. sorry to bother you a bit, but its either fix this quad up or now my boy wants a bigger quad like a yamaha blaster.
FYI im not too mechanically inclined so Im trying to do most of the install myself and have never looked inside of a CVT. Is it easy to replace springs or should I search all of So Cal for a shop that would touch the yerf dog?

 

Sorry. The 20mm is the carb. The 53mm is a cylinder/piston kit. I've got a trinity style pipe, the Keihin with K&N, aluminum cylinder kit with high compression head, carbon fiber reeds with aluminum block, aluminum clutch, 5grm rollers, yellow torsion spring (either 1500 or 2000 rpm, I can't remember). It'll easily climb anything I want my kid on.

I was pulling wheelies accross the front yard the other day without lifting on the bars. It's one quick mini.

 

We aren't in the sand to often. I see you are looking for a shop in SOCAL so you might be familiar with were I ride. Normally we go to Superstition/Plaster City which is light sand and hard pack dirt, the 1500 works great because I get tire spin with knobby tires, the 2000 rpm would probably work better all round but I'll stick with the 1500 for a while.

The clutch work isn't to bad. I'll upload some picture of mine since I have it apart right now waiting for a belt. The left pully (one with rope and tape is the variator, used to keep everything inpplace until I get my belt today) comes from the engine and has the weights, simple changeout. The right pully is the drive and has the spings, 3 small ones up under the cover and the one large one, hardest part was trying to get the small tight springs in.

 

You just need an air wrench and the clutch work is pretty easy.

 

Raptorlegs

Wow your son must love his QJ100, by the way what is a QJ100? If your sons quad pulls wheelies with you on it I can imagine your sons tearing things up. Sounds like you've put in your share of mods to it. Does your quad with all its mods need constant tuning? My boys will eventually want to hop it up for speed, but now he just wants to sound cool. Again there are no places that work on the chinese quads out here so Im pretty much on my own as far as installing it myself. I am pretty handy with tools, but wont bother too much upgrades if the quad needs constant tuning.


Thanks again for all you support!

 

sssduane

I've heard of those places you ride, but since im just getting into riding more often, its a place I'll have to check out. ive been to Glamis and just love it!! I still will do my annual trip to pismo. cool you have a kfx 400!! How do you like the pipe you've chosen? I also have a 03 kfx400 and will soon get a pipe and jet kit!! Feedback on your experience on your set up will help me decide when im ready how im setting mine up. Thanks when you get pics set up for the clutch stuff. Raptorlegs says I'll need an air wrech, dont have that but I hope I can get by with good old muscle!! IM waiiting to hear back from Billy on what I need to get my boys pipe working correctly!

Thanks as usual for your input