750/4 Secondary Shaft Drive Damper Rubbers

Rebuilding a 750E engine and noticed some play in the secondary drive coupling hub. Dampers are shrunk and hard. Ordered up some new dampers from Partzilla and waiting and waiting... Tried Bike Bandit and they found four (need eight), but at least they had them to me fast. In the mean time Partzilla said they finally received the parts so those are inbound too. At any rate, parts availability is not the question, just venting a little.

Question: the dampers have numbers on them. Does anyone know if these numbers have significance? I'm assuming no but not sure. Maybe they are mold cavity numbers? Doubt they have 60+ cavities though. I've measured the rubbers and can't see any difference. Any wisdom on this situation is welcome.

I don’t believe the numbers are meaningful as far as using the dampers. I have a set of 8 NOS ones that all came in the same, original 10 pack (2 had been removed). They have different numbers molded into them with the lowest number being 38 and the highest being 56. Ed

Interesting, all my clutch baskets have some play, but none of my three 550 primary hubs on the bench right now.

My guess is if there are any relevant differences in the size or weight between the damper rubbers the last digits of the part number will be different - as with all parts that come in different sizes. The colour coded main bearing inserts, or different thickness z900 crank dampers, for example, each with it's own unique part number.

Still waiting on the last 4 dampers and apparently the PO lost the package. I'm majorly PO'ed. I'm not surprised really. Every time I've seen the local postal worker they are talking on the phone while working. Just going through the motions. Bet the package was delivered to someone else by mistake. My only hope is the recipient is a good sole and gives the package back. In the mean time my engine lays open on the workbench. I'm itching to get this thing back together but no.

Is there any reason why some damper rubber pieces couldn't be made from neoprene rubber sheet stock? Similar pieces are commonly fabricated for clutch hubs. For about $27 a piece of high grade neoprene could be purchased from McMaster Carr, and it would be simple enough to fabricate the pieces needed for a set of dampers. I've tested a stock damper and determined that it's durometer is 70A. I'm at a loss to find a better option at this point.

From what I can determine online those dampers are still available, so any online or local dealer should be able to get them for you. Ed

I think stock is depleted. I've got a backorder at Bike Bandit for some, and Partzilla has to wait 2 weeks to get the parts from Kawasaki that were subsequently lost. I'm not sure but I think the parts I received were the last ones around.

Taking a flier and going to fab up some of my own dampers. Bought a sheet of "ultra strength neoprene" from McMaster-Carr... www.mcmaster.com/#catalog/121/3564/=ysivfs

The temperature rating has got me concern but pretty sure this is similar stuff to that used by various guys in their clutch hubs, and those are holding up fine.

So did you ever try to DIY dampers? Sorry to write in an old post....but I am interested in your results.

I tried to make some but failed due to impatience. In order to make them properly some fixturing is needed and I didn't want to go through all the work. Found the OEM dampers I needed which made the whole project moot anyway. I've still got the rubber material if anyone wants to have a go. I've also got a spare set of new dampers too.