2001 YZ426F shifting problem. Any recommendations...???

Bent shift forks would be from shock (a fall on the shift lever, too much pressure on the shifter from your boot, etc..) but the worn gear dogs I'm not sure about. I'm not sure what would cause that unless you shift without the clutch (do you?) and/or rest your boot on the shifter. Maybe someone else will have more conclusive info for you.

Hello fellow YAMAHA riders.

4 months ago my 2001 YZ426F started to jump out of 5th gear every now and then...during enduro-rides in heavy muddy terrain.

But getting worse and worse, turned out to be a bad 3rd and 5th gear. The dealer replaced this for free, and told me that yamaha made modified gears for this bike.

So i got those in, but last week i had exactly the same problem again! Took it apart and the "claws" of the 3rd gear that are falling into the 5th gear seam to wear of their sharp edges and are kind of rounded, also the 4th gears "claws" are not looking fresh at all...!

And the 1st shiftfork is showing heavy wear and tear. The steel little axle where this fork is mounted on, which slides in the aluminum casing of the engine has far to much freeplay to my opinion. Did i bend the shiftfork when taking a fall, or what is wrong here...?

Any similar experiences/ suggestions..?

Pls let me know.....

oh bytheway, i love this bike...!

Come on guys, there must be some experts around here.....?

agree with sirthumpalot.

I have a 2001 and blew out 4th gear. It initially stuck in gear and I finished the moto.

Did not determine what it was correctly (thought it might have been a rock or mud jammed in the shifter), as it shifted when I did the around the block test. So I raced it the next week, and while I was leading a moto going down "Suicide Hill" (no lie LOL) I heard a LOUD CLUNK!!!! Again I nursed it to the finish, hey I still won! LOL

Well it seems that plastic trophy cost me as I probably should not have ridden it after that.

Anyway the damaged parts were:

4th gear

cluth drive gear

Excessively worn parts were 4 more gears and 4 bearings. Total PARTS BILL (& I get discounted parts) was around $600.00!!

I was amazed at the wear (dogs and intermating gears) were worn. I did frequent oil changes ran Yami lube non-synthetic, I have since change to Mobil 1.

I use the clutch 90% of the time. But tend to Powershift under race conditions.

It now shifts great and have had no further problems.

I was wondering if you have look at the entire tranny and forks? It really sounds that the forks are bent, this would account for the gears being eatin up or damaged. The other point is shims, shims may or may not be the issue but if you have the wrong shim in the wrong spot this could cause mis alignment in the tranny and forks causing wear and yes bending of the forks.

If the yami dealer has worked on it, do not underestamate the stupidty of a 6 buck an hour mchanic.

Taking the engine apart is very simple to do and gives you great insit on the workings of the bike.

Buy a digital caliper 40 - 100 bucks and tear the motor down. The Manual has all the specs on the sizes of all the parts, make sure all are in spec and the shims are in the correct sequence.

Good luck

[ April 07, 2002: Message edited by: EgoAhole ]

I can't give any input to the problem, because I'm tranny challenged, but it occured to me that the faster guys break higher gears.

Wpoke - you're riding in fifth gear in heavy, muddy terrain? Randy Hawkins, move over.

G-man - you were nailing it in fourth going down a suicide hill? Carmichael, who's you're daddy?

I'm reading your posts with some envy - If someone removed fourth and fifth gears from my 426 (behind my back), I wouldn't know they were missing until I went riding on a dry lake bed.

I once rode two motos in second gear (I didn't shift all day), so I guess second gear will fail first for me. Time to kick it up a gear. :)

I use 3rd all day, almost never 4th and I haven't seen 5th in ages. You keep it in 2nd and when my 3rd and your 2nd goes email me and we'll swap gears. :)

I had 3rd and 5th dog teeth fail on mine too , one shift fork slightly bent. Yes I use the clutch , I feel the gears were soft from manufacturing . I'm a professional mechanic by trade and I changed my oil every other weekend! I used 10w50 Yamalube semi synthetic. After this failure [skipping in 5th gear only]. I had a clutch basket 5 inch gear blow into 3 piece, about 4 months later. Thats when I traded it , Yamaha offererd me no assistance. So I'm done with them! I told Yamaha about Thumper Talk and the hundred people who have had these gear failures but they could care less.

[ April 12, 2002: Message edited by: dan Rekito ]

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