KX450F vs. KX500

[dans89kx500]

I'm looking into buying a new kx450f. I currently ride an old kx500. I ride it everywhere, track and on the trails. Now I want to leave the past behind and step into the future. How would you compare the two bikes? Are they just apples and oranges?

Thanks for the info

Dan in Vacaville

[gowen]

You can't compare the KX500 vs. the KX450F. It's apples and oranges. From the little posted info about what you are looking for, you will benefit from the 450F. I'd go for it.

[KXcam22]

I might be able to help here a bit.  I have been riding my KX500 and my CRF450 back to back a few times (for the sake of comparison I am considering the CRF and the KXF as equivalents).  They are definitely apples and oranges.  First thing I noticed was noise.  The 4-stroke is deafeningly loud, like riding thunder. The KX500 is pleasantly quiet by comparison.  Power is no comparison, the KX500 has more everywhere, bottom, mid, top end, not even close.  Traction is a different story, the 4-stroke just goes forward really quickly without a lot of fanfare, while the KX will spin and fishtail - This is the most noticable difference.  The KX idles down to zero RPM, lugs nicely and can crawl through tricky sections. The 4-stoke coughs and stalls everywhere.  I stalled 20 or more times the first ride on the 4-stroke.  My KX500 is really comfy but the ergometrics of the new bike are fantastic, handling and turning are effortless.  Weight is about the same but the 4-stroke seems heavier when putting it up on a stand.  Kicking effort is about the same, except the KX500 starts first kick every time and 4-strokes take some learning.  My first 4-stroke start was 20 kicks.  The KX500 is great in whoops, but the 4-stroke beats it, gobling up any whoop you launch over. Maintenance on the 4-stroke is at least double (or tripple).

However, the 4-strokes are the future and the are very nice. You won't be dissapointed with the KXF450. I would be on one if my dealer was nicer.  Hope this helps. Cam.

[dans89kx500]

Great email Cam, you really answered a very vague question that I asked. I love my k5, its a great bike. The only real complaits are traction (fishtailing is an understatement) and vibration. It starts easy and will run every weekend with no problems with little maintance.
I have never owned the new modern 4 strokes and the kxf450 seems like a great bike. I see the way they fly around our local mx track (argyll park) with the rider seeming to give not as much effort as the k5. I am the only guy on the track with an older open class bike.

Dan in Vacaville Ca

[KXcam22]

I forgot to mention one final but significant difference.  On the KX500 warms up nicely when it sits and idles while you put your final riding gear on.  The 450 4-stroke is practically boiling over by the time you get your helmet on. Boy do they run hot! I think engine ice, overflow bottle and even possibly larger rads could be in order. Cam.

[stewart]

the only reason the 4 poke is the future is we have let the epa control us,,2 stokes dont drop valves  ,,break valve springs  or lose cam lobes..topend job 150.00  2stroke///1500.00  4 stroke   ..feeding 4 stroke riders roost  pricesless

[KXcam22]

Actually, in a race 2-strokes probably burn less oil too. Cam.

[dans89kx500]

Thanks for the reply's. So IYHO would you just buy a new 250 stroke over a 450? The problem is, only KTM still builds an open class two stroke (300cc). Boiling over a 4 stroke or drops valves sound a bit scary. I'm 37 and have never owned a 4 stroke or ridden a newer model. Im also still not sold on buying one.


Thanks,

Dan in Vacaville

[KXcam22]

The KTM 300 is a nice bike, best bottom end power I have found compared to the KX500.  New YZ250 looks nice too. With my new 4-stroke I am not worried in the least about valves and other issues.  I single track ride so the bike will not spend extended time at high RPM, only short blasts while I get my jollies.  I am also a maintenance nut, love synthetic oil and clean my air filter lots so I am expecting at leat 100 hours between valve changes.  I put a rad catch tank on and will probably try some better coolant so temp should not be an issue either. Bought a 15oz FWW on ebay to cure the lowspeed stalling thing.  Transfered my poor-mans enduro computer. Put on a full compliment of fork, rad guards and skidplate, shark fin in the making. All I need to get is a larger gas tank and then the new 4-stroke should be as close to equivalent to my KX500 as can be.  Time will tell how it works out for me.  I do know that riding the bike is like magic, ergos, handling, traction, and just about everything together make you feel like a super-hero on wheels!  Cam.

[SMPKX500]

I don't understand how the EPA has regulated us to four strokes?  Why not a two-stroke with direct injection?  Fuel injection? And possibly other technologies to release less hydrocarbons.  We have the technology we can rebuild him.

[gwcrim]

You can have my two strokes when you pry them from my cold dead hands.  I so glad that I'm so slow that I don't care about having a state of the art bike.

[Kev]

You gentlemen left out two very droolable options. All you have to do is pony up the greenbacks and get either the CR500AF or the KX500AF.    I should be able to afford mine when I'm 50.   It is an option however. Or the increasing in popularity heart transplant. Does anybody have dollar figures as to the cost? I love my 2 smoke, but I also love the new chassis's. I'm also giving thought to getting a 450F (not replace my 500), but as Cam mentioned, I'm concerned about the maintenance. I don't mind maintenance, but I have only limited spare time and more time riding and less time maintaining is where I'm at.
Kev

[KXcam22]

Ride report:
I have about 6 hours on my 4-stroke now.  I have been noticing some significant differences between the KX500 and 4-stroke power delivery, and some other items.  First off when climbing slow, ugly hills the KX500 is far superior.  With the KX I can set the throttle at a fixed 1/3 and modulate the clutch to crawl up almost anything - never stalls.  The 4-stroke on the other hand does not like that and will stall at suprising times (and in the worst places).  However, on the KX500 1st gear is unusable for hills, if I hit 1st I turn around right away since all the KX will do is dig a big hole in the hill. The 4-stroke will chug in 1st gear and traction up without digging a hole.  With the 4-stroke you can apply noticeably more power in a corner, and it powers out of the corner faster with no fanfare, no spinning, just rocket forward motion, 2 rides and I can already corner faster.

Maintenance: did the the first oil change - was fast and easy, not as much of a pain as I have heard.  My bike uses separate engine/trans oils with oil filter on the side.  I used one of those "billy-who" funnels (a must) and calibrated my own tupperware oil jug (0.25 at a garage sale) for the fill amounts.  Didn't even make a mess. On a 4-stroke it is much safer to use a pre-cal amount of oil rather than the level holes on the bike, which are generally innacurate.  Now that it is broken in I will switch to Amsoil synthetic for the engine and Type F ATF for the transmission. Cam.

[n2682]

i can give the new 4 strokes some credit here but not tons i had a yzf 426 with a few mods hot cams and had the head drilled so it would relieve pressure that builds on the top end but man that thing ran so hot that i was afraid to let it run 2 mins if i wasnt moving down a trail in 90 + weather and have u guys ever seen inside a new 4 stroke engine it looks like they dont even bother to clean slag off the molds it looked as if u was taken apart a chinese lawn mower motor. but that bike would run past any cr 500 i ever had but it constantly needed the valves re adjusted. and i agree with cam the thing thunders outta corners it just puts the power to the ground in a way thats are undecribable to a 2 stroke. i change my 2 stroke crank oil every day if i ride it more than 4 hours anyhow so i dont see much difference there but i let my buddy take the bike for a ride and he didnt do anything i wouldnt of done and it blew up hard would of cost me 2,400 to get it fixed better off just gettin a new motor i ended up selling the chasis to a guy that had a yzf 450 motor sittin in his garage was just easier to part with than to fix in my book and the 250 4 strokers blow up way more often than there big brother the 450 i have alot of friends that race the new not so bad *** 4 strokers and wow what junk  i rode a ktm 300 the other day i got to give it to that bike its got alot of grunt for a 300 if i was to buy new thats what id buy!

[ericac]

what could be done to make the 500 have the clean takeoffs of the 4 strokes? flywheel weight maybe, or different gearing? i would love not to dig 6 inch holes everywhere (at least not all the time!)