First of all I want to say that this is a great forum for information......Many times I have been stumped with a problem and have found the solution from one of the members....Thank you


Well my problem is that I have a 2005 KFX50 and it just goes too slow for my son even with the restrictor removed.

I did see a Red Cat FX-55 at the local track and it was pretty quick, but I believe that this model has been discontinued. The 4 spd tranny seemed to give him the advantage, plus the 4 stroke (no mixing/injecting), remote kill, electirc start and much lower price really made me think about a non-Honda,Suzuki, Kawi or Yamaha machine for the first time. The wheel base did appear to be narrow so it was a little unstable while turning at speed...The rider kept the bike in 2nd gear and seemed to accelerate well and still have a decent top speed.

Should I dump $400 into the KFX with TC racing(Head,Intake and Filter Upgrade) or dump it and buy something else? It broke my heart to see him getting lapped by the quicker bike when his thumb was giving it everything he had.

Any advice would be vey much appreciated..

 

Welcome to the forum, there is alot of information here.
There is no need to dump $400 in the little quad.
Do you have both restrictors out of the motor?
I did under $200 dollars worth of work to my son's and it really improved the power.
Milled head .045, fmf exhaust, re-jetted, and drilled holes in the air box.
Do a forum search on IT50 for the information that you need.
Good luck and feel free to ask any questions.

 

Those mods seem easy enough and they are not going to break the bank...

Which FMF pipe did you use and did it come with recomended jetting?

I found the TurbineCore 2 on the FMF site...


I took Dillan out to test ride a Red Cat KMX50 today and I wasn't impressed with the quality in comparison to the KFX50, but it was only $599 compared to $2,000, so if I was buying him his first ATV and I didn't have the KFX it would have been a Red Cat in the garage, but to get one now, even though the 4 spd tranny is attractive feels like I would be going backwards quite a bit on quality.....

I will gather all of the notes from the forum and start working on a plan to get the green turtle up to speed.

Thanks for the information

 

you mention removing the restrictor on the lil 50. if i'm correct there are 2. one in the exhaust and one in the intake of the carb. to get to these you need to remove the exhaust. look in the head and there should be a washer. likewise on the intake. "CAREFUL" not to break the intake gasket. i'm pretty sure this will take care of your lack of power prob for the green turtle. i put a fmf turbine core 2 pipe on my lt50 "same engine". and no they didnt send me any more jets. but i was always told thats it's better to run fat than lean and smoke a engine. check on ebay for the pipe under suzuki lt50 and suzuki lt 50. "NOTE THE SPACE". hope this helps and welcome to the forum.
sandmouse

 

Please note that the credit for thes mods need to go to bluetickracing a member of this forum, I just followed his guide lines and It worked excellent for me, he also suggested removing the oil-injection and going to pre mix which I have not yet done.

The FMF pipe you listed is correct, it is a complete exhaust, but it does not come with the gasket so make sure you purchase one.
It is only $143.00 from my local suzuki dealer, I would buy a new one for that price.

Check your cranking compression before you mill the head, an older machine like our son's may need rings/ bored, ( my sons was 2 months old). After milling the compression should be around 160 psi.
Just mill .045 off of the head for more compression.

There is a restricter in the intake, it resembles the one in the exhaust, just place a screwdriver in the slot and remove.
Take a 1/2" steel dowel or drill bit, place in the intake and fill the recess where the restricter was and fill with J b Weld.
Remove the dowel or drill bit and sand the J B Weld transition area smooth.

Carb jetting: buy a 70 main jet, and remove the pre-pilot jet over pilot jet.
Move the needle jet up 1 clip.
Drill (qty 5-6) 5/16 holes in the air cleaner lid. (Remember to cover with duck tape if hitting any water)

Torque the head to 104 inch/lbs.

Parts needed:
Intake gasket
Head gasket
Exhaust gasket
70 main jet
FMF Turbine 2
J B Weld
Text

It really makes a difference these little machines need all the help they can get and to the best of my knowlege this is the best bang for the $$$$$$$.

 

sandmouse by removing the restrictors and adding the pipe you are now very lean, rejet before you melt the poor little 50.
Check your spark plug, there is no way your are running rich unless you have an oil injection problem.

 

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Check your cranking compression before you mill the head, an older machine like our son's may need rings/ bored, ( my sons was 2 months old).

Sorry I need repost a typo my sons was a new machine and required no ring/rebore.
Sorry for the confusion.
An older machine will require compression test before the mods.

As I posted before anybody feel free to ask any questions.

 

If you want to really want to wake the quad up go with either the graydon or CT racing pipe They are the only ones with a chamber, the fmf pipe helps a little but not nearly as much as the other two. There is a guy whos son has a 05 kfx 50 with a fmf ex. and its alot slower than my sons 05 lt 50 with ct racing pipe. Worldwideperformance.com sells the pipe its about 220.00 thats a little cheaper than the graydon and the same shop makes both pipes. My son to got bored with his quad but know he loves it its alot faster.

 

It50200,
Hey thanks for the pics your boy looks like he is having a blast. He looks like a pretty big boy for his age.
I will agree with you also that a pipe with a chamber will make more power, but when I put my boys together the FMF was all that I could find.
By the way the nerf bars are too cool, I am going to have to make a set for my kids now.

 

I NEED SOME HELP..

1-I removed the restrictor from the intake and added the JB Weld and smoothed it out (Exhaust restrictor had previously been removed)
2-Drilled holes for more air in the airbox
3-Remove the small jet (the one in the farthest) and put the other jet back in.


The bike started right up and even sounds a little meaner, but now it bogs when giving full throttle??? It starts first pull and idles great

The clip was on the 4th down from the top already...There appeared to be 5 clip settings, but since it was in the 4th from the top or 2nd from the bottom I left it where it was

Any ideas why it is bogging and almost stalling under heavy throttle?