kx500 horsepower rating

dirk_411 · 08-22-2008, 12:20 PM

guys, I know I could search old posts, and I am....

I'm looking for info in regard to issues related with the kx 500 motor. reason is I have all the core parts to try this, I'm looking to build a drag bike only...... so keep in mind, limited riding....

I commonly hear about vibration? Now are we talking vibration as in, vibration felt on the bars or something comparable to vibration when your car/truck tire is out of ballance.

I'd appreciate replies from guys who have first hand expirence only.....

thanks

SandGeek · 08-22-2008, 12:38 PM

I have ridden a '87 TRX250R with a '96 CR500 engine transplanted into it. You feel it in the bars....more specifically, the elbows. I took this one out across a freshly mowed hay field for about a half dozen passes. That's all it took and I was done. I often hear the effect refered to as fatigue but its not really a tired feeling, its more of a premature muscle pumpish thing that happens.

It was fun as hell and quick too. The gearing was a little short but I don't know that it couldn't be fixed with the right sprocket combo.

For a drag only bike, I think you would be fine. If I was going to do a drag only bike, this is the route I would take. Staging would be the worst of it as it. You could take it to the dunes as a novilty but I don't think you would want it to be your primary bike.

**o4twinpeaks** · 08-22-2008, 12:54 PM

Could always do a rubber / polly mount

Like the engery suspension bushings

Would take some machine work but is dooable

Tobys 2 strokes · 08-22-2008, 03:09 PM

In my opinion there is nothing else quiet like a kx 500 or CR for that matter.
Its kind of like comparing a small block to a big block.
You can big bore these 250s all you want and they do run good but not the same as a 500.
My T3 is a blast to ride. In neutral you wonder if the clutch and brake levers are going to fly away. they vibrate so much and you cannot keep a flag mounted due to the vibs transfering out the rear of the frame but once under way you hardly notice it, but its a trike the fourwheelers are supposed to be much worse.
If mounting them in rubber would have worked the manufacters would have done it it would have been much cheaper than counterbalancing them A lot of differant ways have been tried but with not the best results.I have some ideas on how to counterbalance one and one of these days Dave Roberts is going to find one of my spare 500s on his doorsteps to play with.
For a drag only bike it would be great you can big bore them and really make them run.

dirk_411 · 08-23-2008, 12:28 PM

Right on thanks guys...... I totally agree with you toby, a kawasaki powered 500 T4...... I'll be keeping my open for a good 500 motor.....

What year kx500 motor would be best based on your expirences???? It would make sense to me to go as new as possible.....

Quote:

In my opinion there is nothing else quiet like a kx 500 or CR for that matter.
Its kind of like comparing a small block to a big block.
You can big bore these 250s all you want and they do run good but not the same as a 500.
My T3 is a blast to ride. In neutral you wonder if the clutch and brake levers are going to fly away. they vibrate so much and you cannot keep a flag mounted due to the vibs transfering out the rear of the frame but once under way you hardly notice it, but its a trike the fourwheelers are supposed to be much worse.
If mounting them in rubber would have worked the manufacters would have done it it would have been much cheaper than counterbalancing them A lot of differant ways have been tried but with not the best results.I have some ideas on how to counterbalance one and one of these days Dave Roberts is going to find one of my spare 500s on his doorsteps to play with.
For a drag only bike it would be great you can big bore them and really make them run.
[/b]

Tobys 2 strokes · 08-23-2008, 01:14 PM

1988 through 2004 are supposed to be all interchangable I have a 93 in my T3 and a 88 and 98 on my bench and they are all the same.Stay away from the 86 and 87s. I bought a 86 brand new and it was a great bike but I guess 86 and 87s are differant and harder to get parts for.
I think for a drag bike an H2 would be a neet engine it takes not much to get 120 HP from one and I have heard of them putting out much more than that. There is a cool picture of one in the archives of E2S
you wouldnt fite the vibration issue with a H2.either

http://forums.everything2stroke.com/attach...mp;d=1110599721
http://forums.everything2stroke.com/attach...mp;d=1110599721

canada's t4 · 08-23-2008, 05:18 PM

toby stop givin me the ideas of takin my kh400 triple out of my street bike and puttin it my quad thats just another excuse for dad to say im gonna kill myself

tecatesr330 · 08-23-2008, 06:36 PM

the vibration is worse on the bolts then the rider. http://www.loopd.com/Members/87tecate4/Pho...20-3c8252603ef6 http://www.loopd.com/Members/87tecate4/Pho...f7-c5227e973456

**nitrobandit** · 08-28-2008, 01:11 PM

Quote:

the vibration is worse on the bolts then the rider. http://www.loopd.com/Members/87tecate4/Pho...20-3c8252603ef6 http://www.loopd.com/Members/87tecate4/Pho...f7-c5227e973456
[/b]

Sweet Pics! That thing looks like a Beast with the KX500 in there....

tecatesr330 · 08-28-2008, 09:56 PM

thanks,you have to run a high 40s or 50 somthing to get it to have any bottom end and really not much if any faster then a tecate motor.maybe a little more top end.i didnt have the 330 yet to race him at the time so.but my opinion,i will take a 330 any day over the 500 i think it has some thing to do with power to waight ratio.(a dirt bike motor in a quad so the gearing is different)so the need for a really high tooth rear sprocket.just my thought,others may feel different.the hardest part was stoping the nuts and bolts from vibrating off.he still has the frame and mount if any body is interested.make offer,not looking to get rich so can go cheap.thanks