YZ450 or KX450

Alrigth guys. I just got a much better job and can finally afford a brand new bike. Im stuck tho. I have only been on yamaha so do i stick with them? or do i go for the new KX450? Both bikes seem great. I like things that both of them have. The only thing i dont like is the new YZ seems to sit 2 in higher than previous years... IDK if this is just how the dealer set up the 08 they have but they still have a new 06 right next to it and it is 2 in lower than the 08. I am 5'9 so the 2 inches scares me as i cant touch easily.

My 08 is my first modern bike ever and I was amazed that it wasn't taller. I'm 5'9" also, but maybe the bike settles more for me (220lbs).

I thought the KX450F was more suited for larger riders?

I bought the YZ450F because it had the best suspension made, mellow power, light feel and a reputation for durability ($).

Well i did read in the reviews that the shorter/smaller riders liked the YZ better, but it just felt weird sitting on it... I do love yamahas rep tho and the durability. If i go yamaha i wont be getting it from our local dealer tho. I hate dealing with them. they just dont have good customer service, and its all really young guys working there and they dont like to help you unless your loaded....

Loaded as in "money up the wazoo" or as in "pass that doobie man"? :thumbsup:

Try going in to your local dealer and try to get something for your Vintage bike.

I would check out the new issue of Dirt Bike magazine. On page 46 they talk about the durability of the KX. The clutch starts to slip after ten hours due to weak springs, the piston only has a life of around 20 hours, and the rod is supposed to be replaced at 60 hours to be safe. The said one of their test riders pushed the stock rod to 80 hours on his 07 and it was unfortunately one hour too long. I love my 07 YZ and have not had any issues yet besides blown fork seals. Just my $.02

I have owned an 06 yz that i just sold, I currently race an 08 yz every weekend, and i have also ridden and raced an 08 kx 450. I work on these things as my job everyday and as far as reliability the yz and KX are far better than the CRF's. All things considered you cant go wrong with either the YZ or KX. I like the KX motor better and the way it turns better. I like my yz's suspension better but its been done up by Enzo. I am thinking of getting a green bike for 09 and hanging on to my 08 YZ.

I would check out the new issue of Dirt Bike magazine. On page 46 they talk about the durability of the KX. The clutch starts to slip after ten hours due to weak springs, the piston only has a life of around 20 hours, and the rod is supposed to be replaced at 60 hours to be safe. The said one of their test riders pushed the stock rod to 80 hours on his 07 and it was unfortunately one hour too long. I love my 07 YZ and have not had any issues yet besides blown fork seals. Just my $.02

I might be getting a new KX just because Yamaha doesn't have a contingency program for my district, but things like this scare the hell out of me.

Yamaha is now offering $750 customer cash on the 08 YZ450. You should be able to get a sweet deal on one of those. I like my 08 but have never ridden a KX.

well i plan on keepin my 2000 YZ just cause i love it so much and have too much money into it just to trade it (pro action suspension and such)

I think i will just stick with yamaha. even if i have to send the suspension away. Also i read the reviews in transworld, and the smaller guy liked yamaha the best.

I might be getting a new KX just because Yamaha doesn't have a contingency program for my district, but things like this scare the hell out of me.

I wouldn't let that scare you at all. Both the Kx and yz's are damn near bulletproof. You cannot go wrong with either bike.

I wouldn't let that scare you at all. Both the Kx and yz's are damn near bulletproof. You cannot go wrong with either bike.

It is scaring me because I'm looking on the KX forum, and they are talking about how many hours they have on their bike and what they have done to them (maintenance-wise). People are like, "I have 80 hours on my KX, and it has been bulletproof. The only thing I've done to it is a new top end, valves, timing, yada, yada, at 50 hours."

Really? 50 hours and you already have to rebuild the motor? I have 150 hours of riding and racing on my YZ, and I've checked the valves once... and they were in spec. If a KX is going to need rebuild every 50 hours, I pass on all the contingency money that looked so good and get another Yamaha.

I wouldn't let that scare you at all. Both the Kx and yz's are damn near bulletproof. You cannot go wrong with either bike.

Trust me, KX's are far from bullet proof. I have had 3 KX500's and 1 KX250, all with problems. I was on the KX forum one time and this guy just bought a new 07 KX450F. He said when he got it home from the dealer ship after he bought it, the head gasket was leaking. On a new bike! That is ridiculous in my book. If you want reliable well made bikes, you can't go wrong with Yamaha's or Honda's.

Trust me, KX's are far from bullet proof. I have had 3 KX500's and 1 KX250, all with problems. I was on the KX forum one time and this guy just bought a new 07 KX450F. He said when he got it home from the dealer ship after he bought it, the head gasket was leaking. On a new bike! That is ridiculous in my book. If you want reliable well made bikes, you can't go wrong with Yamaha's or Honda's.

you compare your kx250 and kx500 to some guy's kx450f? the blown head gasket could be an mftr error, and i used to have a 98 kx250 and after 8 years on the same piston (who knows how many hours) the thing was still in amazing condition. the crankcase seal went out and all the oil went with it and destroyed the engine, but all of the mechanics that looked at it said it was a freak accident worthy of happening to any bike. but still she ran rock solid up until then.

I have the YZF, but i got be honest if i were to buy a new bike right now it would be the new KTM or the KXF, the thing is they are all so good now, its almost a matter of picking what color you like!!!

both are great bikes, but yamaha is even greater yz all the way

Trust me, KX's are far from bullet proof. I have had 3 KX500's and 1 KX250, all with problems. I was on the KX forum one time and this guy just bought a new 07 KX450F. He said when he got it home from the dealer ship after he bought it, the head gasket was leaking. On a new bike! That is ridiculous in my book. If you want reliable well made bikes, you can't go wrong with Yamaha's or Honda's.

I work on these things everyday....its how i make my living. I'm telling you that you can't go wrong with either the KXF or YZF. I could have bought any 450 i wanted....I bought an 08 YZ....that was after i raced an 06 YZ for a year and a half. With all the bikes i see in service, The yz's and KXf's are by far the most reliable. You say go with a honda for reliability? That just tells me you don't know what your talking about. With all the CRF's valves i have replaced in the past two years??? its ridiculous. I sent Mr Honda a Christmas card and thanked him for all the money i made last year on CRF's. I have raced an 08 KX 450 and the motor is better than my YZ. It handles better also. The yz's suspension is better. Take your pick..you can't go wrong with either bike.

It is scaring me because I'm looking on the KX forum, and they are talking about how many hours they have on their bike and what they have done to them (maintenance-wise). People are like, "I have 80 hours on my KX, and it has been bulletproof. The only thing I've done to it is a new top end, valves, timing, yada, yada, at 50 hours."

Really? 50 hours and you already have to rebuild the motor? I have 150 hours of riding and racing on my YZ, and I've checked the valves once... and they were in spec. If a KX is going to need rebuild every 50 hours, I pass on all the contingency money that looked so good and get another Yamaha.

My buddy i work with has over 150 hours on his 06 KX 450.....He just now replaced a piston and some clutch plates. Other than that the thing has been bulletproof. It also gets raced every weekend....thats pretty good for 2 years.

My buddy i work with has over 150 hours on his 06 KX 450.....He just now replaced a piston and some clutch plates. Other than that the thing has been bulletproof. It also gets raced every weekend....thats pretty good for 2 years.

Yeah... that makes me feel better (no sarcasm). Why are guys rebuilding the motors at fifty hours... not trying to contradict you or anything. Just wondering.

My 2 cents - I bought a used 03 YZ450F 2.5 yrs ago, it hadn't been rebuilt or anything - not even new clutch plates. I don't ride as hard as a pro but I have been racing MX with my 03 since then and I never use the clutch upshifting, often not when downshifting either. I don't use an hour meter but I only change the oil every 5 races or so, don't even wash the filter (K&N) every race - basically I neglect it and it keeps on ticking. Had a YZ426F before my 450 and the same story there.

Dirt bike magazine seems to have forgotten back in their aug. 2007 issue they previewed the 2008 kawasaki's. They said how the '08 kx450 had the crank altered to reduce vibration. a new oil pump, and changes to the oil jet that squirts on the underside of the piston. Kawasaki has these changes listed on their web site plus a new connecting rod material with a harder surface. So it sounds like they've been working on the problems.

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