Just when we thought our Jack Moore modified KFX80 couldn't get any faster, we were able to turn it up several notches with a Chris Grissom modified Keihn 20 mm (bored to 22mm) carb and reed cage. The difference being with noticebly higher hp, the quad is able to get to top speed very quickly. I had to go from 3 rollers to 4 to gain more top end. With the Moore mods alone, we were able to pull holeshots against all modded kaseas (except for a $9,000, 110cc kasea that he pulls about even with), go head to head with some of the super mod cr85's and kx80's, and compete in the blaster/250 fourstroke class with a 2nd place win last week. Now, I'm afraid, he'll spank most of them (though there is still this one kid with a cr85 mounted in a TRX90 frame that could pose a problem). This little screamer literally smokes our modded 250ex. I would recommend this set-up to anyone looking to get the most out of their LT80/KFX80. Here's a run down of our mods.

Moore Mods - porting and clutch work (also, 4 rollers and 1-1.5mm thinner belt)
bored w/ ProX 51mm piston (around 86cc)
shaved head
Chris Grissom - Keihn 20mm bored to 22mm w/ bored reed cage
Trinity Exhaust
Works shocks all around
Case reinforcement all over especially rear end mounting bracket bolt holders (we broke 2 cases in this location)
Douglas rims w/stock front tires and snowhog rears
JL front end extenders and durablue rear axle (likely to invest in atv racing a-arms for better travel)

 

I'm happy that worked well for you.
The very best of 2 worlds. [img]i/expressions/face-icon-small-happy.gif[/img] [img]i/expressions/face-icon-small-happy.gif[/img]
I've gotten a cpl emails asking about this post. So I thought I'd give you a jest of my thinking of it.

a copy of a email reply:::
I saw the thread. Grissom is a great guy and does great work. He started me out and helps anytime I ask. The guy that badmouths Grissom I have no use for. He's that good of guy.
I've heard of the cage/carb. It's like $500....His complete LT80 build is quoted at $3500.
IMO::The rider is still the difference. My machine beat Grissoms in the TT series this year. The machine beat had the carb/cage. He (Grissom)says it gives 1 more HP. Alot of money for 1 hp.
I've had other motors run as fast as any. It's all in how much the owner fine tunes things. Some just do not have the machanical ability's to do a super fine tune or the patience!.
One guy said the dial-a-jet/20mm was the best thing ever, and gave responces similiar to the atvc post.The TT machine of mine actually got to the track and removed the 20mm that we just spent hours tuning and put the stock carb back on cuz it revved higher. That machine was on Hetricks heels and in front of Mr.Strongs very fast Dinli. At that track (Paducah) I guarantee that they were doing 60 mph minimum down the back stretch.

[img]i/expressions/face-icon-small-smile.gif[/img]

 

I hear you Jack. After many hours of tuning and experimenting, I believe I've got it dialed in. I'm sure it's a combination of your second-to-none port, head, and clutch work, matched to Grissoms carb/cage work, with a little more displacement, blowing through a great Trinity pipe. I'm sure we got more than 1 hp by adding that carb/cage. As an apples to apples comparison, we race with a friend of ours (a Suzuki dealer mechanic) whos kid has an LT80. His machine is armed with CT racings top of the line total package mods. It's not even close, about 15yds ahead in a 80yd holeshot and way ahead after 1 lap, and this was before the carb. I'm sure they can get up around 60mph since my modded 250ex maxes out at that speed and the little kfx almost keeps up with it maybe closer to 50mph. The 80 just gets there much faster. I'm sure different gearing could put it past 60. I'm running 13T front 25T rear. Thanks in part to ebay, and Moore racing's very reasonble rates, all the mods done to the quad so far is less than $2,000.

 

mrdirt,

That's cool. Sounds like a sweet setup. Wish I could watch it in action [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]
I love these lil LT/KFX mini's, they are great.

I just got my motor back from Jack that he had to go through.
I'm looking forward to getting it going and playing with it.
Trinity pipe is in the mail [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]
But I lack the experience and knowledge to finely tune to get "top" performance.
He gave me a couple jets to try out, just need to figure out what I'm looking/listening for.
Going to run through a couple different front size front sprockets, with my 26 rear.
I'm looking forward to trying to figure it out though.
We are racing right now on a small/tight mx track, where getting the holeshot is a huge deal, and quickness out of the tight corners is needed.

This should be fun [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]
I'm desperately trying to save my pennies to send my other stock motor to Da Man Jack[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

BTW Jack, the motor arrived today, same time as my tires/wheels [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]
Thanks a Huge Bunch.........
Frame and stuff going to paint shop this week, hopefully put the puzzle back together next week.

Good Luck with your machine [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

 

Hi,

I am interested in doing some modifications on my KFX 80, right now its totally stock. Could you help me with the info for where I can buy the same modifications that you have listed as well as any tips you can give me for installing. I live in Hawaii so the parts and tech help is limited due to the fact that the motocross business is still pretty new over here.

Mahalo nui loa (Thanks alot), Ben

 

1. Send motor to Jack Moore aka "LT80" send him a private message
2. Go to Trinity Racing website and order Trinity exhaust
3. Search Ebay ( lt80)
4. Shocks - best price I've found so far http://www.cdracingonline.com/

 

Hey MrD,

Have you ordered the shocks or anything for the website above?????
Wonder why the Works for the LT80 are so much cheaper???
Looks like good prices and I might order, but not much for ordering from websites I don't know anything about.

Thanks a Bunch

 

Their price list is out of date. The front shocks I bought are closer to $300. I've also purchased a complete set of elkas for my KFX400 with no problems. They are a site sponsor of exriders.com so if you become a forum member they give you 10% off.