WR450 Starter Update '03 to '04 Part Numbers

OK everyone. Here they are! And yes, they do retrofit from the '03 to the '04.

5TJ-15560-00-00 Torque Limiter

4GY-15521-00-00 Shaft for inside the Torque Limiter

5TJ-1549B-00-00 Side Case Cover for the Torque Limiter

90201-105A8-00-00 (2) Thrust Washers for the T.L.

5TJ-15411-10-00 Side Case

5TJ-15451-00-00 Side Case Gasket

Total $345.65 Retail


Thanks for the info. Yamaha should recognize their problem and give us all a kit. It was their design flaw not ours!

they should have made it so you just have to replace the actual gear and the cover :)

Damn I was hoping it would be under $100. Guess I'll be riding with the old stuff, hasn't failed me yet but I was hoping for piece of mind.

Thanks for posting this info :)

How easy was the changeover to the new parts? 1-2 hours? Any special fit issues? Thanks for the info and great work! :)

I got the prices for some of the parts off of PowersportsPro.com. The ones they had prices for were:

4GY-15521-00-00 Shaft $5.04

5TJ-1549B-00-00 Side Case Cover $24.15

5TJ-15411-10-00 Side Case $77.15

5TJ-15451-00-00 Side Case Gasket $3.07

The part #'s for the Torque Limiter and thrust washers came up empty. Do you know what the individual prices were? So far the total is $109.41 so that leaves about $235.00 for the torque limiter and washers. Seems kinda high but it could be. :)

I haven't done the change yet, because I am lobbying Yamaha Corporate to pay for it.

The Torque Limiter is $204.00 Retail from Yamaha.


Ouch! :)

PBD Blue and I have compared the 03 and 04 parts. The only difference between the Crankcase covers is that the 04 Crankcase cover has a bushing installed in the mounting hole for the torque limiter to accomodate the smaller diameter of the torque limiter "axle" as compared to the "axle" of the idler gear used in the 03 Crankcase cover. If you can find or manufacture a bushing to press into your 03 Crankcase cover, you can install the 04 torque limiter into the 03 Crank case cover with no problem. You will have to buy the 04 Cover (torque limiter) however, because the 04 torque limiter is taller than the idler gear used in the 03 Crankcase cover. We were unable to accurately measure the inner and outer diameter of the bushing in the 04 side case. We did measure the diameter of the axle shafts of the 04 torque limiter and the 03 idler. The 04 shaft was .391" and the 03 shaft was .471". The depth of the hole in the Crank case cover where the shafts were installed was .370" in both the 03 and 04 covers. So, if there are any machinists out there who want like to take on the task of determining the dimensions of this bushing and locating a source for procurement, we all would all be very grateful.

I can get the bushings made but what material is it made of? steel, bronze, brass, nylon, graphite? Any ideas? Shaft is probably 10mm (0.3937"). Are you saying that the outside diameter needs to be 12mm (0.4724") and the length 0.37" so it will press into our old covers?

Is this supposed to fix the problem with the electric start on 03 models? My bike starts one out of ten times at best. :) It has been very frustrating. I am so close to selling it. But if this thing fixes it I will reconsider. Someone please give me details as to what this kit is supposed to fix. Thanks

Your problem is the jetting. You need to richen it up. A bigger start jet and opening up the fuel screw will help. A search will give you the rest of the jets needed.

If it is jetting, why does my bike kick over first time almost everytime?

I actually bought the bigger jets right after I got my bike but have yet to install because someone had asked me that same question. What do you think? Did yours kick over fine?

The bushings Yamaha puts in the cases are magnetic indicating they are some kind of ferrous metal (steel). I would think bronze might work pretty well also. I measured the shaft with a digital caliper and it is 10mm exactly. When you make the bushing don't forget to provide some clearance (.001 - .002" maybe?) as the bushing also acts as the bearing for the torque limiter. The torque limiter does not have it's own bearing like the idler gear does. In other words the shaft spins in the bushing. Good luck. I'll be looking forward to hearing how this works out.

Thanks for all the great info. I'd like to know what downside there is to a change over. Added weight. More mass for the starter to turn over, etc.

We need a list of all serial numbers that have failed. We can then carry that into the dealer and get results, especially if it appears that the group is ready to contact legal counsel. Otherwise Yamaha will present that your bike is the only one that failed thus you must have done something to it.. :D

If parts cost $345, then installation by dealer will bring the total to $750... If you do the installation and it fails again then it will be your fault. .. Who can compile the list of serial numbers, and a letter to Yamaha for all of us to sign? :)

As PBDBlue indicated, the bushing is magnetic. That means it could be made from mild steel to high quality stainless steel. Remember, both the 03 Idler gear and the 04 Torque Limiter only turn when the Starter motor is engaged. We were unable to measure the hole in the 04 Crankcase cover, because we did not have an inside micrometer, only digital vernier calipers which would not reach to the hole in the case. We measured the outside diameter of the axle shafts of the 04 Torque limiter (.391") and the 03 Idler gear (.471"). The only way to get the actual measurements is to take them from the 03 and 04 Crankcase covers. We think that there are some industry standard numbers at work here. Possibly a bushing that is 12mm OD x 10mm ID x 9mm Long might be just right or at least a place to start. Any machinists out there want to comment?

The outer diameter of the bushing should be something like 12.02(-0.005) mm if the hole diameter in the case is 12.000 mm and the inner diameter of the bushing should be 10.01 (-0.005) mm if the outer diameter of the shaft is 10.000 mm

I looked at the DIN 1850 standard and the nearest size is 14 OD x 10 ID x 10 - it could be possible to modify an existing bearing to fit in the case.

Hi, I've been following this for several months because I'm planning on getting an '04 (I currently have a '98 and love it). I believe the crankshaft and rotor have been changed (different taper) on the '04 but I have not seen the '04 parts list. Does anyone with an '04 have the ability to measure and compare this with an '03? From all I have read and heard I believe this is the cure.

bajafool asked for a comment from a machinist on the bushing so i thought i'd throw in my two cents. i doubt yamaha used any sort of standard in the bushing size. they had to fit a new part into an old part. n.c. lathes can spit out bushings like this all day long. what ever diameters are needed. the o.d. is probably a bit bigger than 12 millimeters. not much, but enough to keep it from falling out or spinning in the sidecase. even common cold roll steels can be hardened to some extent. as was posted before, it is only "used" when the starter is used. i'll post the dimensions when i can get hold of a dial bore gage to check the i.d. on the '03 sidecase. if we're lucky the bushing will be on the dealer's parts blow up. it is a "bearing" pressed into the side cover and may need to be replaced because of wear. if not, i will make my own and will post all the dimensions i can come up with.

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