Hi all,

I bought two KFX 50's (2007 models) for my boys from Santa. I will start off saying I really like these bikes.

My review:
Note: I only considered 2006 and 2007 models. Most were 2007 models.

When I was comparing the 50cc class bikes I considered each of the major brands. The Yamaha Raptor 50 was to heavy and a slug to boot but had a larger chasis for your kids to grow into. The Suzuki was a small chasis and very sluggish. There was not a Honda 50cc bike to consider. I am not sure why Honda does not make one. The two finalist were the 06 Polaris Predator 50 and the 07 Kawasaki KFX 50. The Predator was fast with a good turning radius, however it was a two stroke, and has a small chasis. The KFX 50 has a big chasis, is a 4 stroke, but was very slow. What I mean when I say slow is the top speed is slow but keep in mind the low in torque is strong. I asked my sales rep if we could line the Predator and KFX up and race them acrossed the parking lot. He agreed and so we raced. The predator had the restrictor already removed and the KFX was right out of the crate.

Race #1: The KFX intially pulled 1 bike length on the Predator and then fell behind by 3 lengths by the time we reached the other side of the parking lot (approx. 150 ft).

I was really disapopinted in the KFX and immediately set my focus on the Predator. Keep in mind I was only interested in a bike my boys will not out grow in a year or so. So my sales rep asked the service tech's to check in the service manual for any kind of restrictor that might limit the KFX. Sure enough they found one. It's a bearing on the clutch shaft that prevents the bike from shifting into the next gear. They removed the restrictor and we lined them up again for a second race.

Race #2: The KFX intially pulled 1 bike length on the Predator again but this time not only did it stay in front of the Predator but it won by 6 bike lengths.

The deal was done. I bought two KFX50's. The dealer removed both bearings for me as well.

Ok, now Christmas has came and gone and we finally have a dry day to go ride. I will skip my training program I setup for them and get right back to the bikes. I intially gave the bikes to the boys with the restrictor removed and the throttle screw pushed all of the way in (most restrictive). The bikes were two fast for beginner riders so I put the bearings back in and left the throtle screw in the most restrictive location. This was much better but I would still prefer it to be a little bit slower for my younger of the two.

On to more of my review: There is no manual choke on the bikes but they do seem to start fairly easy. One of the two bike likes to stall frequently when coming to a stop. I have increased the idle speed to correct this problem somewhat. The same bike has a throttle cable that may be bad. If you grab the cable it will rev the engine however it does not do so when moving the handle bars left and right. I am going to contact the dealer regarding this problem. I have just received a safety recall letter from Kawasaki regarding the steering nut. It may come loose causing a loss of control. The corrective measure is to torque in down to a new specification. I will contact the dealer to get the new torque specification.

Now for the WOW factor. The boys absolutely love them. They ride great and have a great suspension for a 50cc bike. Don't let me forget the looks, they look awesome. I will ride on the back of the bike with the younger boy and it will pull me and him up a 45 degree hill no problem ( I am 180lbs he is 50lbs). I am very happy with my purchase and would highly recommend them to you.

MISC. My purchase price was $1499 plus tax. This was an advertised price in the ATV trader. I also bought a Suzuki z400 for myself. I wont write a review here on this bike but WOW is it awesome.

I hope this reveiw helps you on your buying decision. Remember safety first, and then fun.

Chris

 

I just bought a KFX 50 for my 7 yr old daughter. Although I was a little dissappointed in the speed, it is perfect for her. Can you tell me what you thought the top speed was prior to removing the collar and afterwards?

 

I suspect the top speed with the restrictor and the throttle screw turned in most of the way is 10mph. I would guess the top speed with out the restrictor was close to 20mph. I was very happy when they took the restrictor out. It was fun for me to ride around.

 

How difficult was it to remove the restrictor and how much time?

 

Congratulations....I'm somewhat familiar with a polaris 50 top speed so when you said the KFX was slower I though oh boy it must be really slow!...Glad to hear you got a little more top speed though as your kids will want it eventually..

 

I bought an 07 kfx50 for my son. He loves it. I didnt take long for him to start complaining about the speed. Went and bought a service manual and took that speed collar out of the CVT. Went and bought some universal UNI filter and opened up the airbox and installed a Keihin pb series 92 main jet. Now it runs good!!! Going to install a variator kit and a front JT sprocket(if I can figure out the sprocket model#) next week. If any of you come across a company that sells no-rev CDI , please share the info. I searched high and low and couldnt find one. I did find a scooter site that shows you how to physically cut into the CDI itself to disable the rev limiter . Im not about to do that until I know for a fact that it will work with the Kymco CDI I have.

 

sry 2 tell u you that the kfx 50 is very slow and u need to get them a bigger and more better quad that will do the job

 

I went to the dealer yesterday and purchased a kfx50 for my 5 year old he told me that there are three thing that limit the speed and power of the 07 kfx50 he told me that there was a washer in the exhaust that choked the exhaust flow and cold be removed, the clutch collar and obviously the throttle screw to adjust throttle opening. Is there such a restriction in the exhaust and should I remove it or leave it in place till he gets used to the wheeler?
I am picking it up next week and I am glad to here that it is a good wheeler. Rapidrobert137

 

Out of the box the LTZ50/KFX50 only does 8MPH on the top. With collar removed about 15MPH. I have measured these speeds with the speedo on my dads Rancher. There are no washers on the 4-stroke exhaust that I am aware of, just the 2-stroke version.

The thumb throttle limiting screws on these things don't really do much because you will be hitting the CDI rev limiter most of the time anyways. CT racing has been promising a CDI wtih higer rev limit since January but they keep pushing the date out of their website. The guy who I spoke with at CT said it is being built by Dynatek but I don't know what the hold up is. Maybe they are just waiting for enough interest to put in a big order for pricing reasons. I suggest people start contacting CT and maybe they will get on it.
CT Racing

 

The throttle limiter screw is way to short and I replaced it with a longer screw.
I am very happy with the speed and the torque of this machine, my 5 year old is able to go slow enough for being a new rider and the torque of the 4-stroke engine pulls him up the hills without a problem.
I have a lt80 for my 9 year old that he started to ride when he was 6 and the problem with the 2 stroke machine is that the throttle screw had to be backed way off so that he could make it up the hills and then he would be going to fast for the flat areas.
I will email ct racing of the cdi box. Thanks. Rapidrobert137