wr 450 2005 starter motor

i took my starter off after i hear crunching sounds ...

just woundering if other guys are having starter motor issues? i did not want to buy a new one (@$450 Aus) so it turn out the bush was worn out and needed to be replaced with a new brass sleeve. pretty poor after 18months use (1600kms) i kick start initially and e-start once engine is warm...

ps it was very clean inside the starter motor, no dirt no water

Any advice??


I had to replace the brushes in my starter, it was fairly easy. Disconnect your battery first.Pull off your head pipe and carb for easy access. Two 8mm bolts hold the starter in place (one is the ground), and disconnect the positive lead. I drew a line along the side of the starter with a felt marker to make sure i put the pieces back together right. Undo the two nuts that hold the starter together and lay the pieces out in the order that they come apart. End cap, stationary magnet housing, armature with two washers, and then commutator end cap. this the end the brushes are attached to. One is held in place with a phillips head screw and the other is soldered in place, each has a spring in behind the brush. Heat the soldered one up with a solder gun and remove it. Apply some acid paste to the new brush connection (cleans it) and solder it in. I used some electro contact cleaner and sprayed down everything to clean out any dust and material that may be in the starter (brush dust/debris). Also check the the commutator for any burn marks. If there are small burn marks, put the Armature into a hand drill to spin it and hold a piece of emery cloth against the commutator to clean them up. When done, slide a razor knife down the gaps between the copper bars to clean out any material to ensure a clearance between the commutator bars (copper bars). When reassembling the pieces, the tops of the new brushes have small dents in them which allow you to hold the spring and brush back while sliding the armature/commutator into the end cap. Give the armature a spin to make sure it all turns freely. Be sure to hold the armature downward into the end cap on a table when puting the stationary magnet piece on, as it will try to pull the armature out due to the attraction/repulsion effect of the magnets. Slide the washers on and slide on the other end cap and bolt it back together, making sure your marker lines you drew on match up. You can hook up leads to a battery to give it a try just for peace of mind. :thumbsup: Throw it all back together and let the dirt fly! :lame:

The owners manual explains it pretty well.



I'm fixing the starter on a WR450 right now. Check the endcap bushing for play before you re-assemble the starter.

I bought new brushes at the dealer but now I need to see if the bushing is replaceable or if I will need to get a whole new endcap. I can't get the old bushing out with anything I have so I'll see if Yamaha has a special tool. If not I will have to drill it out or have it machined out so I don't wreck the endcap. What a PITA! Not even 2000kms on this bike either! :thumbsdn:

Sean :devil:

Well Yamaha doesn't sell just the bushing or the endcap. They want you to spend $350 CDN on a complete starter! Firetruck that! I'm going to have the old bushing pulled or machined out and a bushing made to put in it. Stay tuned.

Sean :devil:

Read this thread. Good stuff on rebuilding the starter :devil: ...SC

Thanks Clark. I came across that thread when I did a search. Good info in there.

Sean :devil:

screw a thread tap into the bush to push it out ( very easy ) or may be a bolt ? Go to a bearing supplier and get a new bush ( very cheap ) if you can't get the exact size get the closest size and suck up to some one with a lathe.Problem solved.

i got my end cap machined too rather than replace the unit

an auto electrician can do the whole job (replacement bush at the endcap side, check brushes and test cost $50)

once i got home i re-installed the starter, exhaust, plastics then pushed the magic button PRICELESS :devil::thumbsdn:

My friend has a lathe and a milling machine and will make me a bushing. I can make my own tool to pull the old one out.

Sean :devil:

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