Hey I stopped at the bike shop on the way over to Seattle, and told them about your bike, they said nobody ever gets a new motor, Kawasaki will always rebuild any motor with any problem with all the parts in the world, but no replacement motors for warranty work, sorry man.

 

I just checked the Service manual for information on the balancer gear (Pg. 8-10), and the gear is actually split in 2 halves, although according to the note, it is treated as a single unit (which is why it only has a single part number in the diagrams).

This is a common type of gear and is used to eliminate any backlash, or slack, between 2 shafts. In theory, when gears mesh properly and their shaft centerlines are spaced perfectly, there are no gaps between the meshing teeth, so the two shafts turn in unison. In reality, however, due to manufacturing tolerances, the gears are never spaced perfectly, so with gaps between the meshing teeth, the shafts can rotate slightly with respect to each other. (Even if the spacing started off perfectly, with wear, the gaps would soon show up.)

To deal with situations where its is not deserable to have any backlash, a special "anti-backlash" gear is used to take up this slack. The gear does this by being split vertically, and uses a spring force between the two halves to "grip" the meshing tooth on the other gear (i.e.: when the backlash gear is not meshed with another gear, the two halves are not aligned perfectly ... they might be off anywhere from 1/4 tooth or more. When it is installed, the two halves must be rotated back into alignment against the spring force in order to mesh with the other gear.)

The service manual note says that a 3mm dia. pin must be inserted across the 2 balancer gear halves before disengaging the mesh from the crankshaft gear. This pin locks the 2 halves of the backlash gear together and relieves the "grip" on the crankshaft gear. This means that there is a tremendous spring force between the 2 halves, so that indicates that although there's not a lot of force being tranferred through the gear (other than the inertia of the balancer), there is a lot of force within the gear itself.

So, Brian, your Conclusion #1b is correct ... sort of: it's supposed to be split, but it seems the gear itself is still the problem.

I hope this explaination was clear. I'll look for an image which should help as well.

Mike

 

That's some mighty fine research there Mike [8D]

 

yes,... it is, thanks for the info... i guess one of those springs on mine was missing, but that throws up the question, was it just never there, or did it come off? and if it came off where did it go? and did it mess something else up?