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Posted by: LT80
If the pipe increased power, I'd think it's pancaking the rear torque spring too soon..
errr..if this machine has a CVT tranny anyways.
Posted by: TRexTommy51
OK, First off Chris should tell you how to set you rmachine up. I am not sure with Pipe he sells now so I will make some general rules for you.
1. Change your jetting. I guarantee the jetting needs to be way, way bigger.
2. Little the roller weights in the variator.
3. Change the torque driver spring to a heavier spring. 1500 to 200 rpm spring.
4. Change the clutch engage springs to 200 rpm or more.
You can't just put a pipe on and it run. Sorry, It requires alot more work than that.
Posted by: Raptorlegs
Tommy is right. Reason it's bogging is the jetting. Once that's right, you'll go about 15-20 feet and it'll take off (assuming it's a decent pipe). That lag is your clutching.
Be sure you have the pipe sealed good. If it didn't come with a gasket, get some high-temp sealant.
Posted by: Raptorlegs
Even with a larger carb, you'll still have to rejet. Can't get around that. BUT it is easier to tune a 20mm Keihen. I can vouch for that much. Billy Holt's always had prompt service and bent over backwards to help me. And those parts and advice have made my mini haul some serious a$$. Can't say enough good things about the guy.
Posted by: Raptorlegs
Those paddle tires can be hard to get rolling. Mine digs like crazy after the 53mm kit.
Posted by: Raptorlegs
Quote
Originally posted by: JBL
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?
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.
Posted by: Raptorlegs
You just need an air wrench and the clutch work is pretty easy.
Posted by: Raptorlegs
Since switching carbs, mines been more reliable after the mods. I've had one or two minor things but all in all, it's been a heck of an investment.
Posted by: HQR109
as stated above you have to install a clutch and variter kit to get the benifits out of a high performance. what pipe is it, does it have an expansion chamber ?
Mark
Posted by: HQR109
if your ready for the 109cc kit i have one i took out of my sons eton. we went bigger. i have a stuffed 47mm crank and 54mm cylinder. if its too complicated for you send the motor to me and i'll put the crank in. we run a 112cc motor now, aftermarket clutch, variator, pully, ported and polished 54mm cylinder, wrh pipe, 28mm carb with boost bottle. this thing will climb trees. check out my pics. oh and everything done by me except the porting and billy at wrh done that.
Mark
Posted by: lon426
Hey I feel for you, I went through the same thing with Chris. He seems to be very busy. I was new to mini racing and I bought most of my stuff from him and I can't help but feel ripped off. The throttle cable I bought was about three feet to long the air filter is junk the lower mount on the plus 3" swingarm snapped off causing the shock to get wedged in the swingarm and destroyed the Afco shock which I had to pay to have it rebuilt.They said that they had never seen a shock in that bad of shape.My son had only rode on it for ten minutes before the mount broke. Oh ya it took Chris around four months to get the shocks to me in the first place. So to say I'm a little bit dissapointed is an understatement.
Posted by: mud91
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.
Posted by: JBL
Happy New Year Forum!
I purchased a pipe from Chris at Miniquad Racing for my son's xmas present. Its now installed on a Yerfdog 90, but did not have a chance to install the clutch springs. But both to my son's and I dissappointment, it is actually running much, much slower and seems to be bogging down when reaching high RPM's. I tried installing an electrical unit supplied with the pipe too but no difference. I've tried to adjust the only screw I can find on the carb which is only effecting the idle speed and seemed to find a setting which helped it a tiny bit but no where near from stock pipe. I took out the air filter and cleaned it, but still same results. Im going to Glamis next weekend for the first time and any quick fixes would really help. I will go back to the stock pipe before the ride.
Finally what concerns me is that Chris at MiniQuad Racing said I did not need to do anything to the carbs since my son only wanted to get a better sound. I have had no luch trying to reach him.
Posted by: JBL
Im not too sure if the new pipe increased HP, but I've put in a new spark plug, air filter, and fuel filter, but still same results. I took off new pipe and noticed quite a bit of black oil in the pipe. No time to worry too much since riding this weekend, but after putting on old pipe, wow my son's quad is screaming once agian. He likes the speed but really wants it to sound better. Other suggestions would be helpful. Thanks
Posted by: JBL
TREXTommy51
Im very dissappointed with Chris at miniquad racing. I advised him what exactly I was trying to achieve and he informed me that I did not need jetting. Against everthing I read in this forum, I was hesitant to do business with him but needed a pipe for Xmas. Since then I've had no luck reaching them. I knew deep down I should have went with Billy at WRH.
Anyways Im was now wondering if simply going to a new larger carb will do the trick. I am not the at all a mechanic but I do know some basics. The pipe was custom built with an expansion chamber and did include a CDI and new clutch springs. It sounds that your kids race 90cc quad and I was going to setlle with another 90 like a viper or even a alpha sport cobra. (I have both for my other boys and the cobra is way faster than the viper) My son's Yerfdog is either going to be scrapped for junk if I cant get it going faster. Your help is greatly appreciated!
Posted by: JBL
Mark,
The pipe I got was from miniquad racing and it does have an expansion chamber. Looks like that last few posts have had work done by Billy at WRH racing. Please read my latest post to Tommy51 and it should give you an idea. My son really would like a screaming 90 but for sand riding at glamis. By the way there are no youth racing companies here in Southern California where I can take my quads to get done for performance. Any input you have to just get quicker 90's will be very helpful.
Thanks
Joey
Posted by: JBL
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?
Posted by: JBL
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?
Posted by: JBL
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!
Posted by: JBL
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
Posted by: sssduane
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.
Posted by: sssduane
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.
Posted by: sssduane
I really like the CT pipe. Check out there website, it should say it all. I got two buddies that have Alba pipes on there Z400's, they are too load IMO and give you top end power but lack on the bottom and mid. Also have another buddy with a Yoshi slipon. I can't stand the Yoshi, just something about the Japanese lettering that irratates the crap out of me.
I'm still not crazy about Glamis, so if I want sand I'll run to Buttercup and play over at Gordons, feel my kids are safer there.
Posted by: sssduane
Forgot to mention, the work can be done without a air rachet, you just have to have some strong A$$ hands to hold on to the variator and the clutch.
JBL mentioned opening it up. I plan on using the high comp head soon and then boring and stroking mine. My son will be moving up to a bigger bike soon but I still plan on keeping this 90 for either playing around, my friends smaller kids or grabbing a beer from the cooler while sitting around the fire.
Email me if you ever make it out to Superstition and we will shoot some Sh&t.
