2001 Yamaha YZ426F project

Happy Thanksgiving everyone! I got a chance to sneak out to the garage and measure my connecting rod end play with a dial gauge. Good news! My connecting rod is in spec with a brand new unit! At least that is one thing I don't have to worry about!

With the first gear,I've trail rode mine a lot and you get used to riding the clutch a little

Is that with a YZ or WR gearbox? I'm changing mine to a WR to make my bike a little more trail friendly.

My clutch tool and new fork graphics arrived today! My full gasket kit is on order so I'm getting there. As soon as I find a new cam chain I should be in business!


As soon as I find a new cam chain I should be in business!


TT store or Partzilla

My gaskets came in today! I sure wish payday would hurry up and get here! Only waiting on the cam chain then I can finally start piecing this thing together. I can't wait to bring this bike back to life!


Hey, I love this project!  One of my best friend just pulled his 01' yz426 out of moth balls and started riding again after an 8 year hiatus and just got back in the game myself about 6 months ago.  I like the WR gear swap, sound expensive for folk like me who would have to have someone else do the work.  


I have to ask, have you thought about getting a 35w stator, running some lights and doing a (barely street legal) dual sport conversion?

I have a 02 426 with a rekluse clutch. I would put a rekluse in and don't worry about the wr tranny. But since you already got it in, are you happy with it?

I would like to throw in a WR stator and flywheel which I believe puts out 100watts. I'll have to see what deals come up.

I would love to give you a review of the WR gear box but I haven't thrown everything together yet. I've heard those Rekluse setups are really nice. I'm going to try what I have now and see how I like it.

I just opened my mailbox and found the missing link(s)! Well my cam chain arrived at least. Now I have no excuses left for not having this thing running in the next few weeks. It's going to be a fun weekend!


Carburetor kit came in today. I thought it would be a good idea to freshen up the carb since everything else is going to be new or rebuilt. I'll have to crack the carb open to see what my current jetting is. I'm not sure if this bike was jetted for my altitude. I live at 4000' and will ride most at that altitude. I will be riding trails that go to 10,000'-12,000'+ from time to time.


I have a quick question. The gaskets and head gasket have metal cores. Do these require any gasket dressing or sealant? I use 1211 on a lot of PWC gaskets but those were made of different material.

Nope.  What it does require, though, is a CLEAN & FLAT head and cylinder surface.  If you insist on using a sealer, use a product by the name of Copper-Coat.

My shim kit came in today. Now I can get these new valves adjusted to spec! Merry Christmas everyone!


Edited by 98yota

I managed to sneak into the garage and get the valves adjusted. I set the intake valves at 0.15mm and the exhaust valves at 0.25mm. I went with the 2000 clearance specs because I'm running the valves from a 2000 model rather than an 01. I set the clearance to be at the tight end of spec to allow some wear without needing to change shims for a while. I should be able to throw this motor together soon!

I got to get a little work done on the bike today. I checked my new piston rings and found they are perfectly in spec. I installed the rings on the piston in the correct position per the manual. I pulled the flywheel using the new tool I ordered and it work perfectly! The right tool always help! Unfortunately my impact driver grew legs and disappeared so I stopped there. I'll pick up a new driver and get the stator off. I think I'm going to run the factory YZ stator and flywheel for now due to lack of funds from the holidays. They are so easy to remove it won't take much to change down the road.

I opened my mailbox and found my brand new oversized radiators and blue hoses had arrived! These things look nice! I think the larger coolant capacity will really help prevent over heating on slow trails.




Are they the ebay Chinese radiators? Mine stock rads are pretty beat up. No leaks, but I am considering new ones.

The radiators are GPI and seem pretty well made. I couldn't pass up a set of oversized radiators plus silicon hoses for $100! I'll let you know how they hold up. I read a lot of reviews and didn't see an issue. I guess I'll find out for myself soon enough!

I got the motor pulled out today. I cleaned up the frame and striped everything off of the new motor that I will be installing on the the motor. I did find one of the clutch spring bolts and springs were missing. One of them had been snapped by the shop that built it last. I ordered a new clutch setup. I had to drill the stator bolts because they wouldn't budge with the impact driver. I ordered them today. The good news is everything else looks great!



don't know if you know this already but there is an oil strainer on one of the two oil inlets to the frame reservoir. Anyway is would be a lot easier to clean with the motor out. just my 2 cents.

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