JFAB's KX500AF

[jfabmotorsports.com]

This weekend at a Missouri State race Super Cross contender Jasson Hussey put my personal KX500AF throught the ringer. His KX450 was not back from being switched over to indoor mode and needed a ride. He picked my bike up Sat. night rode it 6 laps in practice Sunday morning. He pulled the holeshot by 3 bikes in the first moto and hung onto that for about 3 laps. After that he started slipping a few places every lap. When the dust cleared he ended up 7th.
   After the moto he told me that the AF was just too hard to hold onto and way more than you need.  It is great for the hole shot but it pulls your arms off.
   Maybe I should have kept the engine stock and not have consulted with Stewart....NOT. Thanks again Stewart.

JFAB
   

[BDI]

10:1 my freind, 10:1 

[kaw rider]

jfab
A programmable ignition with switch on bars for change of timing curves. A curve for holeshots then a curve for smooth power curve.

[stewart]

10:1 my freind, 10:1 

brain do you mean 10to 1 on compression.  i think jerry   set that motor at 13.5

[DoldGuy]

He has "TRUST" in your work!

[BDI]

10:1 my freind, 10:1 

brain do you mean 10to 1 on compression.  i think jerry   set that motor at 13.5

Yes Stewart That's what I mean. From my experiance with other bikes 10 to 1 makes for a very rideable bike. I think a full tilt Stewart engine with a comp of 10 to 1 would work awsome on the moto crosss track. My buddy had a 98 yz250, That 250 was the fastest production 250 I have ever seen. The power onset was as smooth as butter. The bike was ran at comp hill for years against countless other bikes. The bike was very,very dominate and would only loose to cr500's by a couple bike lengths.It would even beat 500cc bikes if rider weight was in favor of the 250 at all. The bikes comp was 10 to 1.

[Larry Wiechman]

10:1 my freind, 10:1 

brain do you mean 10to 1 on compression.  i think jerry   set that motor at 13.5

Yes Stewart That's what I mean. From my experiance with other bikes 10 to 1 makes for a very rideable bike. I think a full tilt Stewart engine with a comp of 10 to 1 would work awsome on the moto crosss track. My buddy had a 98 yz250, That 250 was the fastest production 250 I have ever seen. The power onset was as smooth as butter. The bike was ran at comp hill for years against countless other bikes. The bike was very,very dominate and would only loose to cr500's by a couple bike lengths.It would even beat 500cc bikes if rider weight was in favor of the 250 at all. The bikes comp was 10 to 1.

How are you figuring this 10:1 ratio? Full stroke, like a static four-stroke, or from when the exhaust port closes?

[Dutch-K5 Fan]

jfab
A programmable ignition with switch on bars for change of timing curves. A curve for holeshots then a curve for smooth power curve.

I'm working on it.

Dutch

[BDI]

10:1 my freind, 10:1 

brain do you mean 10to 1 on compression.  i think jerry   set that motor at 13.5

Yes Stewart That's what I mean. From my experiance with other bikes 10 to 1 makes for a very rideable bike. I think a full tilt Stewart engine with a comp of 10 to 1 would work awsome on the moto crosss track. My buddy had a 98 yz250, That 250 was the fastest production 250 I have ever seen. The power onset was as smooth as butter. The bike was ran at comp hill for years against countless other bikes. The bike was very,very dominate and would only loose to cr500's by a couple bike lengths.It would even beat 500cc bikes if rider weight was in favor of the 250 at all. The bikes comp was 10 to 1.

How are you figuring this 10:1 ratio? Full stroke, like a static four-stroke, or from when the exhaust port closes?

Full stroke

[wicked500]

nice pictures

[jfabmotorsports.com]

I was looking through my pics and came across this one. It was taken after practice. One of them is Jasson who rode my KX500AF and the other is Kyle. Guess who was on the 500! 

[Dutch-K5 Fan]

I've ridden a cr250 in the 250/500 class in holland. Once we had a combined race 125/250/500 and my brother and some friend asked why I used Roll off and 2 tearoffs. Is my way to come true the first corner behind a openclass bike


dutchie


PS Was it the right guy in RED

[KawPatty]

That looks like 2 stroke roost. Notice the lack of gaps in the roost pattern.  From the looks of Jason it doesn't look as though he was hehind anyone.