My 2007 KFX50 with 86cc Big Bore results...

[airmobile101]

Ok, heres the deal, nothing impressive,but theres a few factors that hamper my times. One being, Im the one riding it!!! I weight 145lbs and second, I don't have the cvt dialed in yet. And third, I couldn't lay too hard into the throttle since the chain was somewhat loose and would skip on the sprocket.

I installed a Beltronics accelerometer on my sons quad? Its somewhat a dyno of sorts with real world results. Its also known as a G-TECH.

So, this is what I have.....

0-10mph 1.22 sec.
0-20mph 4.18 sec.
0-30mph 13.86 sec(I need to close the gap)

8HP 9pk32mph

Now, my carb is a Keihin PE20MM with a 95 jet and the third clip down. That is dialed in. I just need to adjust the cvt. Its apparent thats its shifting to fast....

More to come tomorrow:D

[airmobile101]

Round #2:D

Ok, I tightened the hell out of the chain and gave it another whirl,but this time, I dropped my rollers from 32 grams down to 27 grams. I still havent ran my 20T front sprocket. And this is still with me on it!

0-10mph .88sec
0-20mph 3.73sec
0-30mph 9.47sec

MAX speed: 34.5mph

5HP average with peak horsepower being at 17hp@31mph

Now, I ran this setup a couple of times with a GPS also at the same time. Numbers are damn near the same with the top speed. I also ran the G-TECH with 3 passes with the first pass being the fastest since the damn chain started to stretch more and slip on the sprocket when I gunned it.

[airmobile101]

pic2

[airmobile101]

pic3

[airmobile101]

:D

[nordic quad]

Keep up the good work,very interesting to follow what works and not in 4stroke tuning:D (PS.do you still have that little 2stroke?)

Stein A

[airmobile101]

Originally posted by nordic quad
Keep up the good work,very interesting to follow what works and not in 4stroke tuning:D (PS.do you still have that little 2stroke?)

Stein A
Yes, I still have the two smoker. I used that as a comparision also. The Kawi walked all over it. Whats really impressive, is the damn torque this thing puts out. Even when it was a 50cc that wasnt modifed. Those GY6 based Kymco engines are rock solid! Its my sons best friend in the tight, rocky woods.

[Chrisd4201]

how is that new carb coming along? would you say it was worth it? My carb is killing my kfx and it stalls wayy to much and im looking for an upgrade....is this a basic install?

[airmobile101]

Originally posted by Chrisd4201
how is that new carb coming along? would you say it was worth it? My carb is killing my kfx and it stalls wayy to much and im looking for an upgrade....is this a basic install?
I honestly can't answer that for you. I don't know what you have done to the quad.

[airmobile101]

I got some fresh cvt parts in the mail coming, so I hope that helps a tad bit also. I opted for a NCY teflon coat variator. Our current Koso variator is about toast. I noticed when I was replacing the roller weights, that the belt started to wear a groove in the Koso Variator. And our Koso gripper bell housing is a tad bit warped, so that has to be replaced also.

[Chrisd4201]

well i ride my quad really hard and its pretty beat up but i mean im going in for a service soon....i just figured that the stock carb isnt too good because i read that somewhere but maybe it just needs to be cleaned or something like that

[airmobile101]

Oh, the actual stock carb is a piece of crap since it has the auto choke on it. I have a few new carbs with auto chokes laying around. They are only 16mm(stock size). I will sell you one for $25.00 shipped if interested.

[Chrisd4201]

if the ones you have, already have the auto-choke on it then what would be the difference between my stock one and the one you have...the reason im asking is because last year i was quoted $241 from my dealer to "clean" the carb and for them to "fix" the stalling problem ...now if your saying that i could buy this carb from you for 25 bucks and i wont have to pay $241 then ill definitely be interested in buying it.

[airmobile101]

It has a manual choke on it! Its a Keihin pb16mm carb. Nothing special about it, just swap your jets around and it should work. Oh, one thing, this carb has a petcock on it. You would have to trim the on/off lever a little bit for clearance. Other than that. It works good. This is the carb

http://dratv.com/ctkoth19dibo.html

[represent618]

that is a rip off to clean the carb, $241 - wow.

i bought a new carb (2006 kfx50) factory direct from kawi for like $85 - through bikebandit, and I had it in two/three days delivered.

this is the two stroke manual choke carb.

[airmobile101]

Well, I sure the hell wouldn't pay that! lol
But, I learned something this morning about jets. Looks can be misleading when it comes to Keihin hex style jets. I was investigating the top end blaaauuu on my kids bike. So, I figured it was the jetting. I thought I had this licked,but I was wrong.......... Anyways, my problem was resolved after a clip change. If you are running those fake Keihin hex jets, its gonna cause you some issues. Those will be the jets with the letters"RD" stamped on them. Depending on what style needle you run, the needle tends to sit higher on the RD jets. Meaning, if I have a standard Keihin hex jet on the 3rd clip, your gonna need to run the RD jet on the 1st clip(very top clip) In theory, You think the 3rd clip is good,but its actually sitting in the 5th or 6th clip. Make sense??? lol

[airmobile101]

Ok, just got done installing all the cvt parts that I ordered from Scooterworks out of Chicago. And I got some good news:D First, I replaced my worn Koso variator with a Teflon coated NCY variator. I weighed them on a grams scale and the NCY was lighter by 3 grams. And I didnt modify it either like I did with the Koso. Next, the NCY variator looks to have a more aggressive degree for belt travel. So I slapped that on with 27grams Dr. Pulley rollers. Next, I replaced my belt with a Kelvar belt and then slapped on the NCY gripper bell housing. Ran it and I happy to say the bike didn't go blaaauuu on me:D . I had to have that re-assurance that the clip theory was true. Anyways, the bike topped out at 37.7MPH. I'm running a 19/28 sprocket combo, So I swapped back to my fave 17/28 combo and ended up running 35.4mph. I think Im done, we are not looking for topend,but torque. All is good!:devil:

[airmobile101]

Correction, 40.1mph after I added another 9 grams:blah:

[thequadfather+2]

airmobile101...you have a pm

[Chrisd4201]

Originally posted by airmobile101
Well, I sure the hell wouldn't pay that! lol
But, I learned something this morning about jets. Looks can be misleading when it comes to Keihin hex style jets. I was investigating the top end blaaauuu on my kids bike. So, I figured it was the jetting. I thought I had this licked,but I was wrong.......... Anyways, my problem was resolved after a clip change. If you are running those fake Keihin hex jets, its gonna cause you some issues. Those will be the jets with the letters"RD" stamped on them. Depending on what style needle you run, the needle tends to sit higher on the RD jets. Meaning, if I have a standard Keihin hex jet on the 3rd clip, your gonna need to run the RD jet on the 1st clip(very top clip) In theory, You think the 3rd clip is good,but its actually sitting in the 5th or 6th clip. Make sense??? lol


does the carb you want to sell me have the problem listed above?? if it doesnt then i would like to buy it from you. also will this solve my stalling problems i have been having? Would you mind going through paypal? PM me details

[airmobile101]

Originally posted by thequadfather+2
airmobile101...you have a pm
Pm sent

[airmobile101]

Originally posted by Chrisd4201
does the carb you want to sell me have the problem listed above?? if it doesnt then i would like to buy it from you. also will this solve my stalling problems i have been having? Would you mind going through paypal? PM me details
No, this carb runs the small round jets. Just swap your needle,slide,and jets and your good to go. Reason you swap the stuff is because its still a different carb,meaning the needle and slide are different than the stocker. Now you can slap that carb on without doing what I mentioned,but I wanted to try to keep it simple.

[TMAN1]

Airmobile101, 40.1 mph that is incredible. Hopefully my sons will get close to those speeds one day.

[airmobile101]

Originally posted by TMAN1
Airmobile101, 40.1 mph that is incredible. Hopefully my sons will get close to those speeds one day.
Well, I am quite impressed with it. I think I can get it a tad faster. The top speed isn't our goal anyways, but its nice to know. My son will never see that speed when he races. He would be lucky enough to see 30mph.

[airmobile101]

Originally posted by TMAN1
Airmobile101, 40.1 mph that is incredible. Hopefully my sons will get close to those speeds one day.
Are you the one asking those questions on Ebay to Autotech seller?

[TMAN1]

No I'm the guy that got the no rev cdi from monster gy6 and figured out how to change the 50 wiring to work with that cdi.

[airmobile101]

Originally posted by TMAN1
No I'm the guy that got the no rev cdi from monster gy6 and figured out how to change the 50 wiring to work with that cdi.
Haaaa, funny you mention that. I just ordered that Velocita adjustable no rev cdi. It will be worth it if I can adjust it without breaking out the damn timing light.

[TMAN1]

I didn't get the adjustable one because I didn't know if it was going to work with the 50. Once I changed the wiring to match the 90, I wish i would have ordered the adjustable one. The none adjustable works great, let us know how the adjustable one works out!

[airmobile101]

Originally posted by TMAN1
I didn't get the adjustable one because I didn't know if it was going to work with the 50. Once I changed the wiring to match the 90, I wish i would have ordered the adjustable one. The none adjustable works great, let us know how the adjustable one works out!
For sure, just waiting on that cdi and and the last two pieces of my cvt to come in the mail.

[TMAN1]

How old is your son and how long has he been riding? Racing?

[airmobile101]

Originally posted by TMAN1
How old is your son and how long has he been riding? Racing?
He has been riding since 5 and he is 8 now. Been racing since 5.

[TMAN1]

Airmobile101, can u post the part numbers for all the cvt parts u got from scooterworks. I went on thier website and was overwhelmed with all the parts. Want to set my sons bike up to move like yours alittle at a time. I created a folder on my computer to log all your great info. Thanks for all your help.

[airmobile101]

NCY GY6 TEFLON PULLEY SET
Item #1200-1152
Your Price: $29.99

NCY CVT Clutch Springs, 1000 - GY6
Item #1200-1023
Your Price: $3.99

NCY Clutch Housing - GY6
Item #1200-1031
Your Price: $34.99

NCY Secondary Slider - GY6
Item #1200-1034
Your Price: $29.99

Here is a few things, but it doesn't include the clutch itself since our Koso was still in good shape.

[airmobile101]

Pretty much anything for a GY6 50cc will work, with the exception of the torque spring, those tend to be hard to find. I think a DRR torque spring will work,but dont qoute me on that. I simply compared our KFX50 one to our two-smoker and they are the same size. Before knowing that, I cut a longer gy6 1000 rpm spring and slapped it in there with no issues.

[airmobile101]

Ok, I installed this "no rev" adjustable cdi box and I wasn't impressed at all. I dont know, maybe the OORACING cdi has a different power curve, but the Velcita adjustable cdi isnt worth it. Didn't matter what position I put it at, it still ran the same times. It pulled the same way and all that crap. Only positive that came out of it was I got to install my original wire plugs for a plug and play type deal. Just buy the standard Velcita dc cdi or one off ebay.IMO

Now, some thing that did get me excited was this nice starter cam plate from NCY performance. That would be that pretty thing that the starter and kick starter assy use to start the bike,and it is also the outer sheave for the belt to travel up. Ok, first off, this thing is aluminum and not steel, and its alot lighter,so that lets the engine spool up faster. Sooooo, once again, Im gonna have to re-adjust our roller weights...............

[shawndadof4]

i checked with some local shops and they do not know where i can get front sprocket. i have stock 16 front 32 rear. we have big bore kit and cdi and pipe, tons of torque but looking for a little more top end, what should i run and where can i buy it? thanks

[airmobile101]

JT front sprocket #JTF 259.17
Thats a 17t sprocket.

You can also order sprockets from Rebel Gears.

[shawndadof4]

thanks for the help, i could not get any help from jt, sent email and did not get responce from them. i called rebel and they had them in stock and set one out right away.

[airmobile101]

Well, I got a new project I'm working on, just need the funds to do it. Im gonna turn this 86cc into a 100cc. I'm gonna stuff a Kymco 51.8mm crank into this bad boy.lol Dont know what it all involves just yet. Im sure I might have to have the cases machined.

[shawndadof4]

good luck, we have a crf50 with a daytona 119 kit and we had to use machined cases. we also have a drz110 with stroked crank and we did not have to machine the cases, so who knows. looks like you will fiqure it out. please keep us updated.

[airmobile101]

Originally posted by shawndadof4
good luck, we have a crf50 with a daytona 119 kit and we had to use machined cases. we also have a drz110 with stroked crank and we did not have to machine the cases, so who knows. looks like you will fiqure it out. please keep us updated.
Well, we have one race left until we hit our one month summer break, so I plan on tearing into it then. Im pretty sure Im gonna need to fab a spacer plate or something.
Dont get me wrong, this thing has some torque already, but I want the knock out punch! Plus, I think my son and buddies son are pretty much the only ones running a 90cc engine or less. Kinda hard running against a TRX125 or a Pitster Pro.

[shawndadof4]

we also have trx90 with tb 114 kit, stock crank. for some reason we bent a valve? in the process of fixing it. after we put heavy clutch springs the thing is a blast, fourth gear power wheelies with my 175lbs on the street. our 50 is no where dialed in like yours but the honda will smoke the 50, but the 50 has more torque with stock gearing. i got the front sprocket from rebel you recommended but have not had a chance to put it on yet. i will be bring the toyhauler home soon and hope to get the sprocket on for our next trip to pismo beach to ride some small dunes. thanks again.

[airmobile101]

Originally posted by shawndadof4
we also have trx90 with tb 114 kit, stock crank. for some reason we bent a valve? in the process of fixing it. after we put heavy clutch springs the thing is a blast, fourth gear power wheelies with my 175lbs on the street. our 50 is no where dialed in like yours but the honda will smoke the 50, but the 50 has more torque with stock gearing. i got the front sprocket from rebel you recommended but have not had a chance to put it on yet. i will be bring the toyhauler home soon and hope to get the sprocket on for our next trip to pismo beach to ride some small dunes. thanks again.
Well.......... if you can tell from my post, our Kawasaki is pretty much history. We upgraded to a 2009 TRX90. Havent done crap to it yet except a LRD exhaust. Been to busy putting my 450r back together.

[shawndadof4]

sorry i did not see post on trx90. see if you can pick up a used 124se top end. what did you do with 50? 50 parts?

[airmobile101]

Originally posted by shawndadof4
sorry i did not see post on trx90. see if you can pick up a used 124se top end. what did you do with 50? 50 parts?
All the 50/90 stuff is sold for the most part.