KX Riders

Maintenance & Technical => KX500 Original => Topic started by: davidvak on July 25, 2007, 09:28:29 AM

Title: KX500 power delivery ? how to make it longer ?
Post by: davidvak on July 25, 2007, 09:28:29 AM
After the negative adventure I had with the NL company ? POWER SEAL
I finally got to ride my beast with no worries. I went to an mx track where
I could open the gas wide as I want?. Loved the incredible torque !!!
I had CRF450 2003 which in my opinion was more aggressive in mid and
high rpm, but when comparing it to the bottom of the K5 the CRF feels like
a good 125 :-D . Any way, I find that my K5 is very short in his power delivery
, again incredible torque but when you get to the higher mid range it prefers
the next gear.
Any advice on how to make the power delivery a bit longer ?
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: hughes on July 25, 2007, 09:38:19 AM
What gearing are your running? Stock is 14/47. Where do you what it to make power?
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: davidvak on July 25, 2007, 08:31:55 PM
it is 15/48,  i have also complete FMF system. (fatty).

i would love to have it a bit higher , a bit longer then what it is now
and i am not talking about long gearing or shrort gearing but power delivery .
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: BigGreenMachine on July 26, 2007, 01:33:56 AM
Go get yourself a GOOD quality midrange/top end port job with the airbox lid off or holesawed.
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: hughes on July 27, 2007, 12:38:47 AM
Retard the timing. It will tame the hit but will give you more over rev at the higher rpm. Carbon fiber reeds work great at higher rpm they will not flutter. Carbon fiber reeds have a high spring tension. Fiberglass reeds have little spring tension and will flutter at higher rpm making the power flatten out.
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: Polar-Bus on July 27, 2007, 04:16:00 AM
Any advice on how to make the power delivery a bit longer ?


Add a flywheel weight. The not only smooth out the wicked bottom end hit, they also create a lenghtened over-rev from the added crankshaft spinning inertia. My 500 has an amazingly wide linear power curve!
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: davidvak on July 27, 2007, 07:20:16 AM
Great! Useful info !
In the past i had RMX250 and KTM 300 , i could change power delivery playing with
the power valve, loading the spring ect... is it possible to this on the KX500 too ?

where would you recommend me to buy the reed and flywheel ??
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: gowen on July 30, 2007, 05:39:16 AM
How much money do you have to spend? There are endless things you can do to lengthen the powerband. Some cheap and others very expensive. The port job and restarding the timing is a great idea for cheap money. Also, I'm a bit suprised that it is all grunt. How bad does it smoke, pop, surge, ect? How do your plugs look after riding?
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: BDI on July 30, 2007, 10:28:38 AM
I had a fmf pipe on my old kx500 I hated that pipe It would just go flat on top and quit pulling. No matter how you jetted It the motor would never seem to peek out In rpms. My favorite pipe I ever used was the pro-circuit pipe good power all over and It would pull for ever on top the rpms seemed to keep climbing and climbing as long as you held the throttle wide.that pipe really works good and lets the K-5 motor screem.That pipe always made me smile ear to ear. If you test those two pipes back to back there Is no mistaking the difference In over rev Its night and day.
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: davidvak on July 30, 2007, 10:40:11 PM
yes it is smoking a bit more then normal, i use Valvoline oil and mixture is 40, (2.5%),
it appears to be jetted ok but takes much to get into working temp, i use 175 main and 48 pilot.

i don't have a big budget, i think i would go for carbon reeds, and next time i replace piston
i will do the port job. what else ????

i would love to get also the PRO CIRCUIT pipe but for the moment this FMF system will be my
call  :roll:
 
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: KXcam22 on July 31, 2007, 08:21:19 AM
The stock pipe gives a good overrev.  You might find one of those cheap.  with ny FMF gnarly it definitely signs off early. Cam.
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: davidvak on August 03, 2007, 08:33:50 AM
just ordered carbon fiber reeds (CARBONTECH), as soon as i put them on i will update
how it runs :-)
any comments on CARBONTECH reeds ?
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: kaw rider on August 03, 2007, 09:16:47 AM
just get the right tension. i put light tension reeds in my high compression motor and they were junk in no time.
Title: Re: KX500 power delivery ? how to make it longer ?
Post by: davidvak on August 03, 2007, 07:49:29 PM
"right tension"  ? you intended to register the stoppers or to buy the right tension type of
reeds ? (my motor has only FMF comb). the reeds i bought are CARBONTECH MT138...
how long do they last ?