What make piston and con rod and bearings to use ?

[Overson]

Hi I'm carrying out a rebuild on my 2003 wr450 and I'm finding it a bit of a mine field about what brand of parts to use

What have people used in the past that are good ?

[SteveThe Snakes]

Good parts are either stock or likely more expensive than stock. Examples are a Carrillo rod, CP piston or J. E. And so forth. Hot Rods and others cranks and some cheap pistons are way worse than stock.

[Overson]

So best to stay away from wiseco, namura and hot rods ?

[GuyGraham]

Hot Rods stuff (Hotcams as well) have a really good rep over on the DRZ400 forum

I've got a hot rods rod in my DRZ for 10K miles and its fine

 

I don't have any first hand exp of the stuff in WR's however

Someone like Noble may have some knowledge

[FORMA MOTO]

So best to stay away from wiseco, namura and hot rods ?

 

Yes, in general.

Those companies make multilple teirs of quality for those bike parts, and the entry level stuff can be Chinese junk.

 

OEM is the only way to go, unless you are building up other parts the motor for a substantial increase performance, and you need more precision or strength.

[grayracer513]

The single most dependable indicator of high quality at a reasonable price is the Yamaha logo on the packaging.  If you aren't going after some kind of nmajor power increase, there isn't much reason to stray from it.

 

There are three basic categories that stuff like this falls into:

 

1. OEM Genuine parts; a known level of quality and reliability that is, with Yamahas, fairly difficult to beat in most cases
2. Premium high performance parts; some of these can be better than OEM, like hardened clutch baskets are, but some others come with offsetting disadvantages like shorter service lives (single ring pistons, for example)
3. "Budget" replacement parts; cheap cranks, clutch plates, and other stuff that is mostly disappointing.

Hot Rods does actually make a good, reasonable quality replacement crank for YZ's, but I still prefer OEM.  Yamaha pistons are all I would use unless going after more compression, and then I would look at CP, JE, etc. (two-ring pistons only).  Not Wiseco for either one.