Taming The Beast!

[kawrider]

I recently bought two new  '04 bikes: a kx125 for my son & the big green monster, kx 500 for myself.  The k5 was a deal & when I heard this was the last year, I just couldn't pass it up.  

A little background.  I started riding as a kid & got my first full size bike, a  '74 KS125 when I was 14 (in 1975).  It was my first two-stroke & I absolutely loved it.  The KS was made only one year & was really a street-legal kx.  I had it tuned so it would really fly & rode entirely in the dirt.  I've continued to ride over the years, but mostly street bikes.  When deciding what to buy for my son & I to ride together (in the dirt), I went back to Kaw and the two-strokes!

The 125 is about what I expected & my son loves it.  The 500 is incredible. Hands down the fastest thing I have ever rode in the dirt.  But too fast to ride on the small tracks around here (my son likes the tracks) in stock tune.  Has anybody out there ever de-fanged one of these babies?

[Paul]

Go to a 50 tooth on the rear, OR a 13 on the front. Maybe both, depends on your style of riding but that will help you greatly on the track.

[mikesmith]

In a world of "got to have a 4-stroke" you made a great choice on getting your KX's!I think the more time you spend on the big 500 the better you'll feel on a tight track.I ride tight single track and have ridden on tight MX tracks and after a while you wont notice how BIG the 500 is.I havent used a fly wheel weight my self but that may help,but Paul has and didnt mention it in his post so maybe it wont.Paul?

[Paul]

Talk to Rick, I HATED my flywheel weight  

[Rick]

Dang, I just might have to start a home for used and abused flywheel weights....

[AFASTboy]

My 5 has a thirteen tooth sprocket on the front and it is still a beast but it makes it awsome for short straits and tight sections.You can just leave it in a couple gears high and chugg it around and when you need the speed just twist it open and hold on.

[Ramski]

I love my flywheel weight. I'm always amazed how low the stall speed can get on that thing before it finally dies. It does make bump starting a little tough though.

In AZ on the tight trails, I liked my 13/47 combo. Lots of people don't like the pull with that low gearing. I only hated it when the washes opened up. Ran out of gears really quick. I imagine the top speed on it with that gearing was maybe 60mph.

[AFASTboy]

13/47 gotta be around 75 or 80 top speed feels alot faster than my old craptor and it would do 73 from the factory

[kawrider]

Thanks for the response, guys, & the support!  I have already begun experimenting with different sprockets, and that has made a huge difference.  As an side note, I noticed lots of comments about top speed & sprocket ratios.  You may be interested in my calulations.  With stock 14T/47T sprockets, the beast should be capable of slightly over 100mph (at 10,000 rpm engine speed).

I am currently experimenting with 13T/52T!  That's lower than anyone recommended, but puts the bike very near the same overall gearing as the KX250.  Of course it pulls like a tractor, but that's OK.  If I keep it geared this way, I will definitly try some flywheel weight, as every ding, ding, ding of the engine is transmitted as a umph, umph, umph to the bike, when going slow!

Slowing the bike down will be easy enough.  But making it happy is my challenge now. I have raised the needle clip one notch (to position 2) and dropped down one size on the pilot jet.  Still running stock #8 plug.  Bike is smoky and sputtery until it get's hot & then it clears up.  I'm still running 32:1 mix. Thinking about trying 40:1.  Any thoughts?

[Paul]

40:1 and a BR7ES will make it very happy I run the Maxima Super M which is a very low ash formula with little smoke AND a powervalve cleaner additive. My powervalves, cylinder and piston rings have always been carbon free and I don't get that "spooge" running this stuff and my silencer packing lasts longer also.

[rhinogrrrl]

hmmm.... Haven't tried the Super M. I like the Maxima products. I've always run Maxima K2 at 50:1

[Paul]

I'm sure you get a good deal on it there monkeygrrrl

hmmm.... Haven't tried the Super M. I like the Maxima products. I've always run Maxima K2 at 50:1

[Paul]

A guppie, is that the best you can come up with  :popcorn:

[rhinogrrrl]

Guppie! ahhahaha  

Well, If you have a Mako or Great White...replace it for me would ya?  I like streamlined, top-o'-da-foodchain predators.

[Paul]

That's why your bike is a KX

Back to the regularly scheduled thread. Sorry for the hi-jack