New bee to the 4 stroke world, What do I look for?

I have ridden bikes for almost 40 years and am thinking about getting a 4 stroker.  I have had very good luck with my Yamaha stuff and am looking at getting a yz450f.  What years and areas should I look for?  I know about looking for wear patterns, head bolts that have been removed indicating removal.  I need to know the nature of the beast and what perks go with what years?  Not really sold on injection yet.  Old school carb guy.

 

I welcome all input.  This is just to putz around on the farm, check fences and maybe occasionally jump the terraces or pond banks.

'06 or later and you get the SSS suspension which is awesome. I just bought a '14 which is my first fuel injected ride, and so far I prefer it to screwing with a carb. I've got the GYTR tuner so I can change the mapping of the engine in just a minute or two. Cool stuff in my opinion.

The 06-09 YZ450's are very good bikes and can be had cheap. You might also look into the 07-11 WR450's. WR's usually cost a bit more but you get electric start, wider gear box, lights and more road hugging weight.

Sometimes you even find them with original tires or front tire. Original chain and sprockets original tank stickers. Those are called cherries.

Sometimes you even find them with original tires or front tire. Original chain and sprockets original tank stickers. Those are called cherries.

That is what I thought too.  I need to know the weekness of these motors.  Cam chain, valve wear, that kind of stuff and how to spot issues.  Leaks are a dead give away.  Buggered nuts are another.

 

Thanks for the info all!

Just look for the lowest milage one you can find. There are no serious issues. It's all about how long it's been used and if it's been taken care of as in oil changes and filter cleanings.

There aren't really any weaknesses of the 426/450 engines, they're super durable and reliable.  I've about 16,000 miles of singletrack trails on my 01 WR426 and it still runs great.  I am very faithful with my maintenance, don't race or bounce the rev limiter.  The bike may look its age, but it sure doesn't run like a 15 year old bike.

 

I've posted the mileage at which I had to do work on the WR in the past, but I honestly don't feel like looking it up after a few tall scotches to wash away the day's stress.  

 

Going by memory, a valve guide seal started to leak a little and smoke on startup at about 8k miles, but it was super minor.  I replaced the rings, piston and cam chain at the 8k mark after turning the bike into a blue submarine and flooding the engine.  We did a full teardown to inspect everything, and I figured why not.  Only the cam chain showed minimal wear, but no stiff or seized links.  It was not stretched that I could tell, it just had a little more sideways "droop" than a new chain.  A single valve guide was replaced at the same time as my valves at around 14,000 miles.  My center intake valve wore to the point of the bike not holding compression and not starting.  The other valves were starting to show wear as well, but still in spec.  Until that time, I had never had to adjust the valves at all, ever.  The valve seats did not need to be redone. I switched to the HotCams autodecomp exhaust cam when I did my valves.  Bearings are still stock and in good condition.  

 

Good luck with the shopping.

Edited by Pooley

Nice idea about the WR, have a few located.  Been doing some homework.  See if I am right here, the WR- "wide range" transmission gears??  Lighting coil and elect start(nice for old knees).  Is there anything else??   What years to avoid?  I am looking at an 06 and an 09.  The 06 is $1k less and the 09 looks way too clean and sanitary, like he is covering something up.  Looks brand new!  Kinda punchy here, besides it is $1,000 too!  I can fix a lot and customize a lot for $1k.

 

Thanks for all the input!

Nice idea about the WR, have a few located.  Been doing some homework.  See if I am right here, the WR- "wide range" transmission gears??  Lighting coil and elect start(nice for old knees).  Is there anything else??   What years to avoid?  I am looking at an 06 and an 09.  The 06 is $1k less and the 09 looks way too clean and sanitary, like he is covering something up.  Looks brand new!  Kinda punchy here, besides it is $1,000 too!  I can fix a lot and customize a lot for $1k.

 

Thanks for all the input!

 

Not much else. The 06 is a steel frame. I would look at the 07-11 WR's. They are the aluminum frame models and all the same. The only real issue with them is the front forks used a spring instead of all shims in the base valve. When it sacks out the bike has the worst suspension imaginable. A easy fix is to use a Racetech gold valve or other that uses all shims. Racetech is even DIY with a DVD.

'07-'11 WR or

'07-'09 YZ

 

The WR's need SUBSTANTIl

'07-'11 WR or

'07-'09 YZ

 

The WR's need SUBSTANTIl

 

Krannie must have nodded off.  

 

The year range of the YZ's should include the '06, the first aluminum framed carbed YZ450 (Gen2). 

 

What he was probably about to point out was that the WR's in that year range need a lot of "uncorking" and then actual engine mods to match up to the output of the YZ.  They are the same basic engine, of course so they can be made into a functional duplicate of the YZ450, but problems will arise with issues like getting the electric start to be happy with the more aggressive cam timing, etc.  There are work-arounds for all of it, though. 

Thanks again all,  Here is what I am looking at.  Comes with new plastics.  Whoopie, won't make it any faster or more dependable.  What is  your idea of value?  Has the original chain and great set on it too. Its an 06

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'07-'11 WR or

'07-'09 YZ

 

The WR's need SUBSTANTIl

 

...the phone rang....yes, '06 YZ too.

 

...SUBSTANTIAL work on the fork and shock, was what I was going to point out.

Especially the forks, they are not track worthy at all without an upgrade kit....and even then..

Good point.  The WR didn't get the SSS twin chamber fork until the EFI bike came out in '12.   Up 'til then, they had the 48MM open bath type fork, and the way they were set up stock was, well it was a way of doing it, I guess.  With what amounts to a completely redesigned valve assembly, they work surprisingly well, especially compared with what they start like, but not as good as what's easy to get to with the SSS fork.  

I wonder if the exhaust cam needs to be retarded like the early YZ and the YFZ did?  What about the high volume oil pump and wrist pin spray nozzle?  Does this need to be done too?  Trying to cover all bases here.  Not real fond of the 18" wheel in the rear.  I can tune/work around the forks and shock.

 

Does $3k sound like too much for this bike?  

Edited by mrjata

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