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Discussion Starter · #1 ·
Does anybody know anything about the YZ490's? Is there a 500 2stroke that stands out above the others over the rest in power?

Is it true that the CR500 has a specail frame so if you put it in another frame itll shake and vibrate alot?
 

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yz490 was a piece of junk, kawasaki wasnt much better. honda has always had the best big bore 2stroke. im not saying you couldnt make a yz490 or kx500 run like a raped ape but the honda is just a much better designed motor.
 

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Discussion Starter · #3 ·
QUOTE (average_joe @ Jun 18 2009, 07:23 PM) index.php?act=findpost&pid=47115yz490 was a piece of junk, kawasaki wasnt much better. honda has always had the best big bore 2stroke. im not saying you couldnt make a yz490 or kx500 run like a raped ape but the honda is just a much better designed motor.

But does it have a specail frame just for the cr500?
 

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i have a 86 trx with cr500 in it and all i can say is hold on.the only thing that holds it back is the quite muffler i had to put on to pass oregon dunes db. its forsale by the way to many bikes and its the oldest
 

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no the triple trees soak up the vibration because there is no counterbalance in the motor, if you put it in a quad frame with the stock crank it will make your feet and hands numb.
 

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QUOTE (LT450R @ Jun 19 2009, 06:29 AM) index.php?act=findpost&pid=47198But does it have a specail frame just for the cr500?


i dont think they have special frames, honda might have designed it a certain way to reduce the vibes but i dont think its "special". i have two cr500 and they do vibrate but not much, but mine are in the 2 wheeler stock frames. ive never tried to put the motor in a 4wheeler frame, but i heard they do have alot of vibration. if your planing to use a 4wheeler chassis, a saber or puma with trx bottom end would probly be a better platform to use because they have a counterbalancer and would most likely vibrate alot less. cr500 will always vibrate to some degree because thats the nature of the beast. however, what chassis you put it in will dictate the AMOUNT of vibration.
 

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Discussion Starter · #7 ·
QUOTE (average_joe @ Jun 19 2009, 11:35 AM) index.php?act=findpost&pid=47210i dont think they have special frames, honda might have designed it a certain way to reduce the vibes but i dont think its "special". i have two cr500 and they do vibrate but not much, but mine are in the 2 wheeler stock frames. ive never tried to put the motor in a 4wheeler frame, but i heard they do have alot of vibration. if your planing to use a 4wheeler chassis, a saber or puma with trx bottom end would probly be a better platform to use because they have a counterbalancer and would most likely vibrate alot less. cr500 will always vibrate to some degree because thats the nature of the beast. however, what chassis you put it in will dictate the AMOUNT of vibration.


Umm can somebody explain a counterbalance, a saber and a puma for me??
 

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QUOTE (LT450R @ Jun 19 2009, 01:51 PM) index.php?act=findpost&pid=47250Umm can somebody explain a counterbalance, a saber and a puma for me??

you were asking about a yz490 so i assumed you wanted a motor around 400cc-500cc, a puma or saber would get you in that cc range and the trx bottom end is a great foundation to use. as for the counterbalancer, a V8 has a balancer on the front of the crankshaft, trx uses a weighted rod driven by the crank to off set the vibes. i could be wrong but i think it had something to do with the design of the 4wheel chassis needing a counterbalanced motor, i think some suzuki 2stroke qauds also had the counterbalancer.
 

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mine doesnt vibrate i had the crank trued welded and balanced. i've rode yfz's that vibrate more.
i think a lot depends on mounting it in take your time to make sure everything lines up and straight and use good steel for mounts. take your time welding not or warp anything
 

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QUOTE (homdaddy @ Jun 20 2009, 09:33 AM) index.php?act=findpost&pid=47357mine doesnt vibrate i had the crank trued welded and balanced. i've rode yfz's that vibrate more.
i think a lot depends on mounting it in take your time to make sure everything lines up and straight and use good steel for mounts. take your time welding not or warp anything
thats the key welded and trued crank
 

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Hey, I would avoid the YZ. The CR5 is a pretty good motor, but the people that build them wont let there secrets out. I am a big fan of the big singles. And I'm a Kawi guy, I have a few KX5 motors, one is in a LT230 frame, which is getting scrapped. And now I am building the frame for my 499cc Alky n2o motor, hoping for around 120-130 HP. If you do plan on doing a big single, if you want to stay away from custom on the motor, atleast get the crank trued, and welded if your going for big HP numbers. Thats most of the vibe problems, was when the crank was pressed together, they werent that true, and the crank halves were way off weight frome one another. So, if you plan on doing this, PM me if you want to do the KX5 motor. would be my choice and have seen a rideable, very wide powerband, 100+ hp at the crank on 115 octane gas. Would make a great motor for a quad.
 

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I had a friend who bought a Blaster with a CR500 motor in it... I had to sort out the jetting for him... I don't know if the crank was trued, but the damn thing vibrated so much the framed cracked, the radiator mounts cracked, the new custom exhausts cracked in all directions and it was mounted on rubber flanges the way it should be...
I had a CR500 bike, she ran really hard, but she vibrated also just as much...way to much for what I like... (not as much as in the quad frame)

Like said above, true and weld the crank will make it better, but the problem here is the counter balancer shaft...
 

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Discussion Starter · #13 ·
QUOTE (BVH Developments @ Jun 23 2009, 05:07 PM) index.php?act=findpost&pid=47807I had a friend who bought a Blaster with a CR500 motor in it... I had to sort out the jetting for him... I don't know if the crank was trued, but the damn thing vibrated so much the framed cracked, the radiator mounts cracked, the new custom exhausts cracked in all directions and it was mounted on rubber flanges the way it should be...
I had a CR500 bike, she ran really hard, but she vibrated also just as much...way to much for what I like... (not as much as in the quad frame)

Like said above, true and weld the crank will make it better, but the problem here is the counter balancer shaft...

Ahh this is confusing!!
So stay away from yz490?
Ive seen a kx500 run and there very fast!! well this one is
 

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Stay away from the YZ.
The CR is good, but hard to find people that really "know" how to build that motor.
I prefer the KX, and all the info you could need is available easily.
 

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i have a cr500 converted to a 3 wheeler i think its much easier to do the 3 wheeler conversion instead of the 250r framed type. the geometry is a lot better and they dont have the head shake the vibration isnt bad at all. i had tim at titan true and fit the crank didnt get it welded. also they really need a compression release fo some sorts i have one from ric's accu mix jugs its got a lil handle bar mounted lever i push when i go to start it it kicks like a 125cc and starts up really really easy now..



i think CP is about to release a cylinder for the cr500 bottom end. if the pipe, head, intake combo gets figured out i am definatelly getting one.
 

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x2 alot of ppl overlook the lt5's they are the most overlooked of the big singles. and they are already in a quad chassis and the chassis is actually very nice for being from the late 80's i know my lt 500 drag bike is a monster and if set-up right will make big power. by the time you find a kx/cr5 motor and then find a good chassis to put it in and get it all ballanced to deal with the vibrations you could buy a lt500 and have it in a frame for cheaper and there not as bad to mod as alot of ppl think they are there is actually a handfull of builders that can build them right to make big power and they have a counter balancer. im building a whole new chassis for my lt this winter its gonna be loaded with all kinds of goodies.
 
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