I'm about to undertake a rebuild on my WR 400 (have owned it for about 8 months, 3000k's mostly motard).
Long story short,
- noticed that forth gear was starting to make an undesirable noise.
- pulled oil filter to find fine metal flakes
A complete tear down has turned up a few issues,
- fourth pinion gear has severe damage with many chipped, cracked, partially missing teeth and forth wheel gear is intact although beaten up from contact with the pinion gear
- piston and cylinder have some scoring (although engine doesn't smoke and has excellent compression)
- cam chain teeth on crank are damaged (i'm guessing from a previous mishap in the bikes life?)
- balancer shatf bearing (right hand side ball type) is notchy (all others seem good).
I really like the bike, have spent money replacing carb parts, swingarm/linkage bearings etc and have generally had the bike completely apart, cleaned, inspected and am happy that its got plenty of life left in it. (I also plan to ride it in the Finke enduro in June, so i'm really keen to get it back together and get some saddle time!)
My plan is to rebuild as a 426 with all oem parts out of the USA (much cheaper than here in Oz).
I will be replacing:
- crank and bearings
- piston and rod etc
- balance shaft bearing
- gaskets and seals
- cam chain
- oil pump rotor assembly
- assorted other unrelated bits
Can anyone suggest any hints/tips that might help me through the rebuild?
Also, I don't have the tools/knowledge/confidence to attempt the crank/rod/piston assembly!
Can anyone please recommend an engine builder in the Brisbane area (Australia) who could do the crank balancing etc for me?
One last thing, can any of you US gents recommend a site for the required parts (that will ship to OZ).
One other last thing, any thoughts on jetting changes required would be much appreciated too!
Edited by Jedmeister, February 23, 2014 - 05:12 PM.