New member 2004 yfz 450 help !

[xXXMATTXXx]

I recently bought a 2004 yfz 450 I was aware of the oil/wrist pin issue. But i rode it anyways and of course it seized on me -_- I havent split the cases yet but it looks like it welded the rod to the crank. I need guidance on what all i need to purchase. If anyone could help who has done this before that would be great :D

Crank what brand ? WR ? 2006 crank ?

what gasket kit to buy ?

Crank bearings and seals ?

Im not necessarily looking for more power i just want it to be reliable so i dont have to dump more money into it.

[xXXMATTXXx]

I see a few people have viewed the thread but no posts yet :/ I would appreciate the help tremendously. I just need some guidance from someone who has done this before.

[quadrider2112]

it depends on what you want to do with the motor. OEM cranks are best. If you want to keep it stock or just go stock stroke and bore with hc piston this is what i would do. ON ebay you can buy a oem to end kit with cylinder piston gaskets the whole 9 yards. Then you sell the stock piston buy a hc one and and OEM crank assy. Then you jus gotta put it together i think.

Well thats my advice and what i will prolly do when mine pops. Just buy all 08 parts and youll be ok.

Im no expert but at least i reply when i saw you wanted help i guess:D

[xXXMATTXXx]

yea thanks for the input :P Ive gotten alot more input on a different forum not guna say the name lol. I am keeping stock stroke and bore. the 06 and above rods are shorter then the 04 and 05. 06 and above make it a true 450 and supposedly lose zero reliability as well :) the wr crank is 1 pound lighter so it revs faster mainly why people use those.
so far i need
cometic gasket and seals
oem crank bearings
oil mod by j & t
and decide on a crank -_-

[QuadforceDavid]

I have done this so many times it's like riding a bike now. I highly suggest that you not only do the crank but the crank bearings also. Your already there and there is a lot of stress on those bearings. You will need all of these parts to do the job. The crank bearing keeper screws are "peened" into the keepers so they won't back out. If you take your time it is a very easy job. Inspect everything as you take the motor apart and make a list as you go. You will find other things you need along the way and the list will prevent you from having to wait extra time on stuff you forgot.
The head bolts have to be replaced also. They are a tension style torque bolt and actually stretch over time. They are cheap and worth buying. It's better to replace them now then to put the motor together and have a nice fresh motor only to blow the head gasket because you have more compression from the build. I also just use the GYTR piston for a higher compression than stock. Just make sure you order the 06 GYTR piston (if you want a Yamaha piston that is made by JE) and your good. One more thing, Yamaha offers a GYTR head and base gasket, I only use those unless doing a motor over 13.5:1. Those gaskets seem to work better than the Cometic and the stock style Yamaha gaskets. Replace the cam chain too, it's cheap and your already there. Check the seals on the output shaft, there's an O ring on the output shaft that wears out on a motor that old and again, your already in there so replace it too. One last thing, there are three lock washers inside the motor. One on the counter balancer nut, one on the crank drive gears, and one on the clutch. If they even slightly look like they are gonna break, replace them. Trust me, it's cheaper to replace all the little stuff than it is to replace a set of cases because one of these breaks.

These are Yamaha part numbers
5TG-11400-31-00 2006 crank
93306-30633-00 X2 crank bearings
90149-06126-00 X4 keeper screws
90105-104A7-00 X2 head bolts (outside)
90105-106A3-00 X2 head bolts (inside)
94591-57118-00 cam chain
93210-22298-00 output shaft O ring
93102-32480-00 output shaft seal
90215-21003-00 drive gear lock washer
90215-20231-00 clutch lock washer
90215-14287-00 counter bal lock washer

Good luck!

BTW, not only is the WR crank lighter, it uses a smaller wrist pin and obviously a different piston. I've never used one, but I have ridden a few with them in it and they rip but, I just don't trust the bike crank in a quad. Lots of torque on the crank that a bike crank isn't designed for.

[xXXMATTXXx]

Good lord. ive been waiting for someone like you to post lol. see i only new of 3 things on that list that i was going to replace crank, crank bearings, cam chain lol. I absolutely agree with the theory of do it right the first time so you dont have to do it again.

Are those the parts numbers to order the parts from the yamaha website ?

A million people have told me have told me to run the wr setup but im with you just something about a bike crank in a quad seems to be asking for trouble IMO.

I still havent purchased parts yet because i needed to get a list together of everything i need to buy and want to get it all at once not have to keep waiting on things i forget about.

[QuadforceDavid]

You can order those part numbers from Yamaha yes. The crank is for an 06 model and all the other stuff will interchange. You can run the WR, I just don't like to. They do run harder and rev faster but I just can't wrap my arms around them. Just me being stubborn I guess. If you do order a piston, make sure you order one for the 06-09 model though. The pistons are different from the 04-05.

If you need ANY help at all with this please let me know. I do all the YFZ repairs for the group of guys I ride with and I have messed up enough stuff to know what NOT to do for sure.

I buy all my Yamaha parts from Stadium Yamaha. They are FAST and they get them right everytime AND they will ship to you from their website.

www.stadiumyamaha.com

[xXXMATTXXx]

so when i buy the 06 yfz crank i have to buy a piston for it as well ?

I thought i could use my stock 04 piston ?

I get payed this coming friday and i should be able to order parts then.

Does the list you gave contain EVERYTHING i need ? Im wanting to do it right even if i have to wait longer for more money. I just want to do it right so it will be reliable.

I really appreciate the help and input :D

[QuadforceDavid]

Yes, get the 06-09 model piston.

04-05 piston part number
99999-03528-00

06-09 piston part number
5TG-11631-11-00


The difference is the wrist pin location. Yamaha does offer a GYTR piston for your motor that increases the compression and it's made by JE.