The crank is seized!!

Well i finally tore my bike apart last night and discovered why it wont kick over, the crank is fried in my bike. I seen a low end from a 2000 yz 426 on ebay, my ? to my fellow tt members is will that low end fit on my 2001 426? i noticed the part numbers are all the same except for the crank assy. What is the difference? Also im considering the 444 kit were is the cheapest place i can find one i want a new cylinder w/ the kit. Thanks

The crank from a 00 426 will fit but the primary gear drive is different from the 01-02 crank assembly. The 00 crank assembly uses a straight key with the primary gear drive and the 01-02 are a spline primary gear drive. You would have to order a different primary gear to get the 00 crank assembly to work in your 01 motor. Try www.lukesracing.com they have pretty good prices on big bore kits. You might want to check with the guys at lukesracing about rebuilding your crank assembly. :thumbsup:

Thanks for the info I have looked into some of their products, and im pretty sure im gonna pick up one of their top end kits. As far as the crank goes the primary gear is the only diff? So if I get the low end that is for sale on ebay my top end will work without any mods. Thanks guys

Try www.crotchrocket.com for OEM parts, they have by far the best prices on parts.

Thanks for the web site they do have some cheep prices. If someone could give me some advise on what to look for in a 444 kit that would be sweet, as in cooling problems, jetting, reliability or anything else it would help.

I am running an 01 crank assembly in my 00 motor and the only thing I had to do was order a new primary drive gear. I have my old primary drive gear from my 00 crank assembly if you need it just email me s37062001@yahoo.com. If you pay for the shipping you can have it. :thumbsup:

Thanks for the web site they do have some cheep prices. If someone could give me some advise on what to look for in a 444 kit that would be sweet, as in cooling problems, jetting, reliability or anything else it would help.

Make sure whoever builds the kit for you (they have to bore a stock cylinder 2mm over stock to get to 444) that they run tighter than recommended cylinder to piston clearance with either a JE or Wiseco piston.

Either piston will work fine but they both need to be run at about .0012 in (.030mm) if you run it at the recommended .003 clearance, the piston will shrink in the bore and start to slap noticeably fairly soon.

This is not a show stopper but it is a noticeable noise and will drive you crazy.

Also the OEM wrist pin is a couple grams lighter than either Wiseco's or JE's pins that come with their pistons, that matters a little since these engines have (relatively) weak rods to begin with.

My suggestion is to take your crank and send it to Falicon and get the supercrank with knife rod service they offer, then you end up with a perfectly balanced crank and bulletproof rod that your big bore will not be able to hurt easily.

As far as the temps go, anytime you run tighter clearances, you will build more heat.

You should also consider some Fluidyne radiators.

You will like the added grunt of the big bore, just be prepared to spend some time jetting it properly as they really beg for spot on jetting.

I spoke to a person a falicon yesterday on crank options and he said they did not offer anything for my bike, which was weird because I seen some products on their site a while ago? He said the only thing they could do was balance and true my crank. Maybe they stopped making stuff for the 426? im not sure.

Also if i buy the kit from lukes racing will they already have the piston clearance correct? Since i heard you have to run tighter tolerances .030 i would guess they have the cylinders already set up correctly?

There kits included everything you need to setup the big bore. I would send your crank assembly to lukes and have them check it out to see if it can be rebuilt. I checked around for after market crank assembly for the 426 and I did not find anyone that makes them. I was in your shoes eight months ago when the bearing on the rod went out and I had to tear my motor down. I would buy a new assembly because if you put one in that is used you maybe rebuilding the motor again next year when it goes out. Just my .02 cents :thumbsup:

I spoke to a person a falicon yesterday on crank options and he said they did not offer anything for my bike, which was weird because I seen some products on their site a while ago? He said the only thing they could do was balance and true my crank. Maybe they stopped making stuff for the 426? im not sure.

Wow man, my world just came to a screeching halt, I have another project bike in the works right now as well as my street legal supermoto, and the plan for the 2nd bike was bore/stroke and go big, but it turns out that you are correct, Falicon stopped making stroker stuff for the 426.

They can however do the supercrank work which includes balance/true and all.

What a bummer......Arrrrrrghhhhhhh........... :thumbsup::bonk::thumbsup::eek:

Thats what i thought i was also surprised because i looked at those cranks, well it looks like its time to look for other options and hopefully your project goes well! For now i have some thinking to do i what way i want to go. My biggest hing is reliability i don't want to work on it all the time.

A little curious price comparison for an expensive part I had to replace.

CYLINDER HEAD ASSY for 2004 Yamaha WR450F.

5TA-11102-10-00

TT Store $471.95

Lukesracing $498.29

Local Dealer: ~$550

Hey sorry to hear about the bottom end seizure. What ever you do with your crank options ( I am currently repairing a fried lower con rod bearing myself in a 400) make sure you locate what caused the lack of oiling to your rod. These are very high output engines and they should be expected to wear out certain parts over time, but frying lower con rods shouldn't be routine. All I am saying is make sure you eliminate what caused the problem in your bottm end cause I feel ya these repairs aren't cheap even when you do all the work yourself. Good luck with everything.

Yes your correct i do have to find the out why it happened, but for now the crankcases are still together probably this weekend they will come apart. I have had the bike for awhile and it has alot of long hard hours on it so im not sure if it was a failure due to time or like you said lack of oil i will know more once i have it out and see it.

I sent my 2000 426 jug to Lukes Racing for the +2mm bore. I forget whom they shop the machine work out to, but they do excellent work. I received my jug, 12.5:1 Wiseco and Cometic gasket kit back for $350 total (inc. shipping). The tolerances were spot on and the bike is a maniac. I've got about 30-40 hours on the motor and not one issue.

I run a completely stock cooling system and use Maxima Cool-Aide, watter wetter and H20 and have had no issues even in summer weather. Jetting will differ from bike to bike and location to location. I ended up with a 168main, 42 pilot and 2.5 turns out. I ride in the high dez @ 3k feet w/ FMF powerbomb, Q silencer and no-lid airbox.

A new crank from crotchrocket.com can be had for $268.73. My local shop quoted my $180+ to rebuild my stocker, I'd pay the extra $80 for a new balanced crank from Yamaha. Your local shop may not be a crook like mine though.

Thanks alot for the info I actually work at a dealer so im gonna probably end up getting new instead of rebuilding mine i dont want to take any chances. Also its good to here that u like the kit hopefully i will have good luck with it like you did.

If you're not a mx rider then consider the 444 kit, 450 cam & quite exhaust. Incredible grunt off idle though the mid. Makes my buds KTM450 feel like a toy.

I have a set of hotcams intake & exhaust that i ran last year it also has a full system exhaust, so when the motor is done this time all the mods that i want (and can afford) will be complete and hopefully its the last time to get into the motor. I dont want to keep dumping money into it because i want to pick up another bike this summer, and the 426 will be a spare.

............you DO NOT want to go backwards and put a 00 crank in a 01. The crank configuration is the weakest link in the 00 426. The primary gear is only held in with a woodruff key - known to break!! And when it does it will wipe out the end of your crank as well as your oil pump, primary gear and possibly your case!! I have a 00 that I did the upgrade mod to a 01 crank and primary gear and it runs great now.

If you are going to split your cases and replace the crank - do it with the newest version you can possibly use!! :thumbsup:

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