Tri-Z 250 and YZ250 Crank

[coyleatc]

I am doing a rebuild on an 86 Tri-Z 250. I see that I can get a new crank assembly from Hot Rod for 83-89 YZ250. I know a lot of these parts are interchangeable. Can anyone confirm that these are indeed interchangeable? Thanks!

[Billy Golightly]

You'll probably need to check with Nathan (03 Orange Shee) because I'm pretty sure he has done the swap, but I'm not sure what year it was from.

[Bryan Raffa]

pro x tri z connecting rod #04981 YES its the same rod
The yfm 225 84-89 is also the same

Im pretty shure if you run the whole crank you have to run the YZ stator & flywheel with it, Witch means NO lights.. I think Moshman has gone through that aspect of it

[Mosh]

IF you run the yz dirtbike crank,It will drop in the tri-z cases.But,The left side of the dirtbike crank will not hold the tri-z flywheel.
In order to run the tri-z stator and flywheel to keep your lites,You have to press the left side journal off of the tri-z crank and swap it on to the dirtbike crank.This will allow you to run the stock Tri-z stator and flywheel and keep your lights.The yz flywheel will not fit over the tri-z stator.So yes,If you dont mind not having the lighting system,Then the yz crank will work,But you have to run the yz flywheel and stator.
IF your stock crank is not trashed,I would suggest just getting the rod kit and rebuild it.They only charge around 50 bucks or so to press a new rod on the old crank once you buy the parts.

[TimSr]

I had my crank rebuilt two years ago with a hot rod kit. As I tore it down last weekend for a top end job, I was disappointed to notice that it already had excessive play. Basically, my rod job only lasted as long as one bore job, and my bore wasnt exactly extremely bad. I also had bought a bottom end that had a hot rod kit in it. I have no idea how much use was on it, but it was tight, and in good shape. A few months later one of the big side washers came apart, killed the cylinder and even broke the cases internally between the crank and gearbox. This is strictly annecdotal, and hardly scientific, but Im leaning towards an OEM rod kit for this time around on this crank.

[Mosh]

I am afriad what I will find in my yellow z this weekend.Hot rods one year ago and I could here a knock coming from it the last time I rode it.:eek:

[Billy Golightly]

I was recently reading on another site how imperfect the hot rods and other aftermarket ones were. If you have the tools to check the exact clearences and make sure they correspond with your OEM service manual their probably okay to use. But, most of them are more then likely very near or already out of spec as soon as they come out of the box.

[tecat-z]

I've heard lots of good things about hot rods, and just a few bad. I put a complete crankshaft assy in my wifes 87 trx 250r 5 years ago and its still as tight as day one. The failures i've heard about have involved Banshees, where crank phasing and twisting can sometimes be a tough hurdle on built engines, no matter what crank it has. I do believe OEM rod kits are superior in quality to the Chinese Hot Rods kits. Generally i always try to use OEM engine components when availiable.

[Bryan Raffa]

I got a pro x in my 86 motor about 5 years ago and recently put some new rings in it,,and it was still tight!

Oem rod kits are still alv.. yamaha #1RX-11400-00-00 crankshaft assem.

[Jason Hall]

I think maybe some of you guys that had rods pressed on your origional cranks might have had them pressed on crooked. If the two counter weights of the crank are'nt true It will eat the main crank bearings fast. You are better off I feel to buy a complete crank assembly rather than have someone at a local shop press the rod on. I have pressed a few rods on myself & It's real hard to get them straight. I believe a Tri-Z has 2 holes In the counter weights. If you make a pin to drop through the hole while pressing the two halfs together that works good. I used a drill bit to keep my little guys kx60 crank true when I did that one. Just my 2 cents though.