View Full Version : NOOB to the KFX80...questions

04-06-2007, 10:16 AM
Hello all...

Just purchased a 2003 KFX80 for my boy. Upgraded from one of those off brand cheapies. He is stoked! I read every thread on this forum trying to gain as much info on it as possible but I still have a few questions.

1. Where are and how do you remove the restrictors on the exhaust and the fuel? Will this affect the jetting on it?

2. What are these rollers peopl are talking about taking off? We ride sand and it can rob power. I want him to be able to ride this out in the dunes sometimes. I purchaed a set of gliders for him already but want to make sure it has the gitty-up.

3.What else can I do to release the power it has now??

4. I also want to pipe / filter and jet it but do no want to gon internal onto the motor (piston, decking, porting) yet. But where and is good place to get a pipe, etc. and how much can I expect?

Thanks in advance for your assistance...


04-06-2007, 08:06 PM
Welcome to the forums!
I can't answer a lot of the technical questions for you (I'll leave that up to LT80!) but my son has an old dinosaur 87' LT80 that is bone stock except for the restrictor plates being gone & he has gliders on it & it goes pretty much anywhere we want to go in the dunes in Oklahoma. If your kid is pretty small, you won't NEED to do the hop-ups yet. I'd really like to start pumping his up, but he's pretty small still & I don't want him to go too fast just yet.
Do what you want/need to with it, but I just wanted to let you know that those bikes really do run good enough stock to get around in the sand pretty good without having to spend the money. Especially if your kid is inexperienced rider, you don't want to go overboard too soon.
Good luck man!


04-07-2007, 02:16 PM
I will chime in and tell you that there a two restrictors one where the ehxaust meets the head, take the two bolt/nuts off of the head and remove the bolt that holds the pipe and bracket pull the pipe off the head and you will find a washer inside the pipe, remove this washer and reasemble the exhaust. The spacer in the carb is a little more tricky, you need to take the top cap off the carb by unscrewing it and pull once loose, you will see a slide with the needle thru it, on that assy should be a brass spacer this limits the travel of the slide, remove that and reasemble make not to readjust your throttle cable.
As far as pipes CT racing makes one FMF also makes one do a search and see what you come up with.

Hope this helps out.

04-07-2007, 03:40 PM
This is the cheap performance upgrades that I was looking for in my post. Thanks!

04-08-2007, 09:20 AM
The CT pipe is the hardest to tune to. The FMF I recommend to my competitors.
LRD makes a nice pipe but $$$. I lean toward the Trinity pipe (225?) for performance. If not racing a DG pipe will work fine and is the cheapest.
The DG pipe will rev a lil higher. Yes it's loud.

Removing 2 of the rollers and shaving the head .030 will help especially in the sand. I'd also take the rear clutch shoes down to 180 grams each.
To work on the clutchs, you must remove the side cover (time consuming but not hard). Once in there, you will need an impact wrench (or equivelent) to get the clutchs off. The rollers are in the front hub.

Yes that's for you too jonboy. <G>

04-09-2007, 12:22 PM
Great info fellas and Thanks. If you have any pictures of the carb mod, please post them up if you can. The bike (as it sits) is pretty powerful. I just know how the sand can rob power. I agree that he needs to grow into the bike a bit before I unleash all the mods. He is 7 years old and weighs around 75 lbs or so...

04-09-2007, 02:52 PM
There's no carb mod that will do anything till the motor is well built. :)