YZ 465 and 490 2 Stroke

Brad

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Anyone rode one of these monsters? My buddy has both. Both be from he 80s but my god they haul so much. Too put in perspective its hard to keep the front wheel down in any gear...

The big companies don't make anything over 250 2 stroke wise correct? Anyone else ride some high cc 2 strokes?
 

hardway

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I had a KTM 495 2 stroke dirt bike when I was in high school (early 90's). I can't remember what year it was, it was from the 80's and I think it didn't have the monoshock. As I remember, it had the dual shock rear end, old school. As I've been trying to find it online though, all the KTM 495's I see have the monoshock. Maybe I'm mistaken.
That thing was the fastest bike I've ever ridden, it was truly insane how much ass that thing hauled. Acceleration was off the charts too. I used to go down in my dad's field after it had been raining for a couple weeks. I could bury the rear tire up to the axle in mud and drive around the field at 30+ mph throwing thirty foot rooster tails and digging 13" deep trenches. Good times!
 
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champion221elite

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I haven't seen a current production 2 stroke dirtbike in quite some time. The biggest 2 stroke dirtbike I rode was a buddies Honda CR250. That thing would flat out scoot!

Coming from a 1986 Honda Fourtrax 250 ATV over to that 2 stroke 250 bike was a rude awakening to say the least. I wound up the motor which promptly put me in the power band. That front wheel came up so quick and dumped me right on my butt. I was still laughing as I was trying to kickstart that SOB for another try. The power was addicting, and wheelies were effortless.

For me, the 250 cc 2 stroke was plenty of power. I cannot imagine the grunt of a 490 cc 2 stroke:eek:
 

poorwboy

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I have rode both. The 490 is fast, but the 465 was real violent and I loved it.

Brings back memories, Is the 465 yellow and black.
 

Fz6Sa

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The big companies don't make anything over 250 2 stroke wise correct?

Yamaha does the XT660

2009-XT660R-static-03_tcm34-271462.jpg



Got my licence on one of these :) (An older model than this one though).

I'm personally not a fan of the 2 strokes, - they need higher revs to run smoothly .....
But as I understand it, a 2-stroke is impossible to kill, - the engine will just keep running for gazillions of miles.
 

poorwboy

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Yamaha does the XT660

2009-XT660R-static-03_tcm34-271462.jpg



Got my licence on one of these :) (An older model than this one though).

I'm personally not a fan of the 2 strokes, - they need higher revs to run smoothly .....
But as I understand it, a 2-stroke is impossible to kill, - the engine will just keep running for gazillions of miles.

Thats a four stroke.
 

champion221elite

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Poorwboy is right. A 2 stroke bike will not run for mile after mile. Due to the high rpms, heat and other factors, a 2 stroke engine will wear out much faster than a 4 stroke engine.

Power output will decline due to loss of compression. Hole shots will become sluggish, and top end speed will be slower. Most 2 stroke dirtbike guys will tear the powerhead off their bike once per season and re-ring the piston.

BTW, the Yamaha XT660R is not a 2 stroke. It's a fuel injected 4 valve liquid cooled 4 stroke engine. 48 rated HP, 44 ft/lbs of torque.
 
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hardway

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Poorwboy is right. A 2 stroke bike will not run for mile after mile. Due to the high rpms, heat and other factors, a 2 stroke engine will wear out much faster than a 4 stroke engine.

Power output will decline due to loss of compression. Hole shots will become sluggish, and top end speed will be slower. Most 2 stroke dirtbike guys will tear the powerhead off their bike once per season and re-ring the piston.

This is correct.
 

Andz

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I rode a YZ465 once back in the days when they were the weapon of choice, a friend had one and I flipped it on a dirt road.... pulled off gingerly then whacked it, the rear knobbly cut a furrow in the road then when I hit 2nd and tapped it the front just came up and spat me off. Luckily he had already crashed it so I wasn't the first!

http://www.vmx.livewire.gen.nz/magazine/81YZ465/81YZ465.htm
 
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Brad

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I have rode both. The 490 is fast, but the 465 was real violent and I loved it.

Brings back memories, Is the 465 yellow and black.

Both be yellow and black

The one he has are single shock in the back. I think the year be 82 for the 490 idk on the 465
 

GastonJ

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I used to have a Suzuki GT550 2-stroke triple in the early 80's, had the expansion chambers, rearsets, flat bars the whole lot, when like the proverbial sh*t off a stick and sounded like a swarm od bees. I sold it on after a year to 2 so that I could get myself a Suzuki GT750, the water cooled 2-stroke triple, which I kept hold of until the kids came along.. It seemed more relaxed than the 550 was, but still wasn't slow.

As I recall Yamaha did try a water cooled 750 around the same time, but I'm not sure it made it out of concept. The only other bike around that size was the Kawasaki KH750, but I've probably only ever seen 2 of those in my life.

Around the corner from where I lived a mate had a Suzuki RE5, now we've wondered off onto strange bikes. I don't recall how long he had it, but it wasn't so long. Was a good talking point when we stopped at cafe's while out and about.

No I feel old :thumbup:
 

Gilo-FZ6

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i love the big engined 2 strokes..i almost bought a 88 KX 500 but the person i wanted to go halves with was terrified by it

there used to be a YZ 490 used to blast around the fields by where i lived.i wasnt even in my teens then..it was the most awsome sight ever ..turfing up the ground in every gear and the sound!!! :eek:..we had an old school YZ 250 for a while..monoshock and liquid cooled but the rad was mounted where the number plate usually goes on the front forks and an 1980 maico 250 with a horrible kick back and left hand kick start it weighed a tonne and went like no other crosser ive ridden since

as others have said reliability is an issue..a well tuned 2 stroke moto-x bike runs best when its on the verge of blowing up much like a RC nitro car

mental note:i Will own a KX500 eventually
 

Gilo-FZ6

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PS did you guys in the states have yamaha TDR's..super fast 2 stroke parralell twins ..moto-x characteristics on a road bike

99e8_1.JPG
 

nmag

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I raced a YZ465 for three years in the early 80's. We modified the airbox and fitted Boyesen reeds and ended up with a real fast bike. A set of Whitepower springs made it handle real good too. We ran it on high quality synthetic oil and it didn't even need a decoke for those three years. Those big two strokes didn't need lots of revs. The 125's did, and that's why their rings and bores wore so quick.
 

iSteve

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I had a 84 CR500 way back. Like the YZ it would accelerate like nothing else and could tow a house. But the 125's were more fun.
 

dxh24

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Kawi made a KX500.... i've ridden the kx 125 and the kx250 both monsters in their own right... my kx 125 i know for a fact has a higher top speed than my yz426f... the kx250 had about the same top speed and similar powerband, not a tremendous gain over the 125 imo.... I've seen a kx500 ridden at a track, well, Absolutely tore the hinges off the competition, think he placed first with like a 45 second lead over a 2007 yz450f (this was a exhibition, pro class though).

I know my little kx125 was the funnest bike i've owned. 2 stroke>4stroke any day!
 
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