WR450 2006 please help with top end rebuild...

Hello guys,

could help me with top end rebuild in my Yamaha WR450 2006

I just hit 6500km and for me its still has a lot of power but I wont make rebuild beter now then have the change that my engine will blow. I cant understand how some of the guys rode 10.000miles before top end rebuild ?!?!....

I found that its started to burn the oil a little bit (its not smoking when I start the engine or something, just found that after 200km I had to add about 50~80ml)

I have the bike from brand new Im the virst owner I change the oil every 500-700km with filter. I checked valves every 1500km for right now all in spec.

I want to order parts from usa because here in poland I have to pay 2-3 time more. I want to order them before winter that I can split the engine and replace everything. Until this day I will keep rideing.

What should I change ?

1 Piston (should I go with OEM or aftermarket ? and should I first measure the cylinder then order piston or can I order without any problem Oryginal Size Piston (standard) ?)

2 Chain + dampers, chain tensioner ?

3 Valves, seats, retainers, lifters, guides,springs ?

4 Rod or complete Crankshaft (OEM or aftermarket)

5 Gaskets

6 complete bearings for linkage,shock,swingarm ( Pivot Works are they good or shoul I stay with OEM ?)

Please if you could help me with this, maybe I should add something to this list or remove from it. For any advise I would be really apriciate.

I want to ride next 7000km without any problems I dont want to change my piston and after 2000-3000km my rod will broke or something elese I hope you know what I have on my mind :-) ....

Very sorry for my english :-( ......



Since no one has replied - I thought I'd help a bit here.

TT aftermarket has great prices, TT OEM has some of the best I've seen on OEM goods. (they are different outfits and will ship from different locations).

1 Piston (should I go with OEM or aftermarket ? and should I first measure the cylinder then order piston or can I order without any problem Original Size Piston (standard) ?)

I would stick with OEM if you are not going to mod the bike - BUT - for the money - WISECO makes a very good aftermarket OEM replacement piston kit that will not change your performance.

With your low hours you won't need to check the Cylinder - likely it will still show cross hatching - definitely get it honed though to seat the new rings.

2 Chain + dampers, chain tensioner ?

You will only need the Timing chain, if you really want to - also get the tensioner, but likely yours will be fine for some time to come. I've never noticed any wear on the dampers yet - even on very used engines.

3 Valves, seats, retainers, lifters, guides,springs ?

Valves, you can go with an aftermarket Kibblewhites or other kit - should come with springs and cotters, seats need to be cut by a shop. Seals should come with the gasket kit I described below. There are no lifters. I would buy a full shim kit or a variety of HONDA shims - Honda shims come in more sizes and are exactly the same diameter.

Valve guides rarely wear, you can probably do 3 sets of valves while keeping the original guides.

4 Rod or complete Crankshaft (OEM or aftermarket)

Crankshafts can also come as a complete assembly including the rod - if you are going this deep, replace the bearings as well, they're under 30 a piece

Only buy the rod/bearing separately if you are able to or have access equipment or someone who can put it together properly.

5 Gaskets

Get a complete aftermarket gasket set from TT - it usually includes every gasket and seal right down to valve stem seals and orings - anything you don't use can be stored for when it's needed.

I got the Moose Racing gaskets complete with oil seals and was extremely happy with it:


6 complete bearings for linkage,shock,swingarm ( Pivot Works are they good or shoul I stay with OEM ?)

Get the pivot works - they're fine and a good price - while you're at it get a set of wheel bearings for front and back, a clutch, several spark plugs, a few oil filters, new sprockets and chain as well as fork seals - these are wear items needed eventually and you'll get a much better price on them in the US and save on shipping if you add it all to this order.

Heck - get new rubber while you're at it!

hope this helps a bit.

dude i have over 9k dual sport and desert miles on my bike and it runs like a top and starts 1st 2nd kick when cold and 1st kick hot. you have 4038.912748miles = 6500km on your bike. you could go long before the rebuild. if i was you i would try different oil to see if the is why its burning and also change it every 300 miles or 450km. also when you do the oil change make sure the oil level is at the top of the dip stick and you should be good to go :)

I don't have anything to add to the rebuild...I just wanted to let you know that your English is fine :) . I will assure you it is MUCH better than most of our Polish!:D


Thank you very much its help me a lot,but one thing if I will hone cylinder can I still put standard size of piston ? or should I go with a little bigger ?

and other this Kibblewhites valves are made from steel and the OEM are from titanium its not a problem ? and they are only for YZ450 are they the same for WR450 ?


I read here on forum that some people hit over 10.000km without any problems but some make only 4000km and they have a big problems, its depends how you ride and what terrein you have.

And I hit my bike really hard in terrein....

About oil I have tryed to change on different oil in last time and it didnt help its still disaperaing a little bit after every ~200km

And its stills start without any problems after every kick or electric start, and still strong also.


Thank you for the words :-), but I know I could be better if would lear more and have a little bit more time.

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