My son has a 2003 KFX50 (LT50A) I removed the Exhaust from the cylinder and eliminated the washer that restricts the exhaust flow. That helped with the top end, but where he rides it is sometimes deep loose sand. Getting started off is sometimes impossible and he needs to be pushed to get going. Will putting on a Htrick Pipe help increase his Low End Power? What else can be done to Increase the Low End? I have also heard that FMF makes a Pipe for this little 50, has anyone heard about this pipe? I looked thru his Maintenance Manual and there isnt any mention of a Brass Sleeve located between the slide and slide cover in the Carberator. Also on these newer model 50's is there a slotted steel Restrictor in the Intake Manifold? when removing this, is it necessary to rejet the carb? Thanks to anyone who responds. Rick

rickscheid@***.net / If someone whats to give me some advise on getting his liitle 50 up to speed. He wants to start racing in the
50 class, but right now it just doesnt have much

 

There doesn't appear to be a slide restrictor in the 03's. I didn't find one in mine. The slotted restrictor is still used in the intake. Mine came out fairly easy after applying a little heat. I also drilled several holes in the air filter cap to help it breath. I changed the jet to a #70. The stock jet is a SMALL round #55. You can not get the SMALL round jets in smaller sizes. (according to my dealer). I used a LARGE round jet. It will screw in no probem. I also stretched the small rubber tube over the larger jet. I believe it is used to draw fuel from the bottom of the float bowl. The low end improved substantually with all these mods. However, the bike is still crippled by the single speed tranny. The gearing is too tall when starting out, and then the motor quickly runs up against the rev limiter.

I don't think it is worth spending the money on one of the pipes for this bike. If your son really wants to race, and you are comfortable with his riding skills, I would sell the LT and buy one of the larger 50's more suitable for racing.

 

Ricky A, I had the exact same problem. I opted to buy my son a more powerful quad. It seems there is little to do to make the LT 50 a screeamer. I'm sure there are mods out there, but you'd probably be better off just getting him a larger displacement machine

 

If they can squeeze 50Hp outta a weed eater motor. You should be able to get some more ponettes from the KFX50.

My son has a KFX50 and he will be wanting to get more outta it soon. I was thinking of consulting a local small engine shop to see what could be done.

I'm thinking that some engine horsepower MODS may be needed.

Larger Carb
Better flow exhaust
More Compression
Clutch changes
etc
etc

I could sell the KFX50 and go with a 80cc or 90cc but I know this little bugger can do more...

 

I'm sure if you throw enough $$$'s at it, you may be able to get more from the motor. You will still have the problem of the single speed tranny, and an inadequate suspension.

In my opinion, it's a great bike to start a 4-6 year old on. It is built solidly and doesn't shake itself apart like my older son's Xtreme 90 does. When the time comes I will sell it and move up to something larger. Until then I feel safe knowing that he is riding a quad that matches his riding abilities.

That's my $.02