TOPIC:

For those who do not know, including me - What are the dangers of riding the bike with a stretched chain?

Yaegunp wrote: For those who do not know, including me - What are the dangers of riding the bike with a stretched chain?

Let's start by saying "stretch" is not the right term here. The link plates and pins that make up the chain are hardened steel. It could be possible for "stretch" if the pins and plates got overheated above 700 F. which is about the temp. required to normalize or anneal the steel. The chances of that happening are slim to nil since the Babbitt in the plain bearings would melt first and you'd be sitting on the road looking for that Harley rider and his girlfriend to happen past

So, what you're measuring is the wear in the pins and pinholes in the plates. Eventually, the "weak link" will break and self destruction will happen. Looking at the crankcase halves I see a shallow weir between the transmission section and the crankshaft section. If the chain breaks it will fly forward and get caught under the flyweights on the crank at #4 cylinder. Chances are the crankcase will be destroyed. There will be a massive spill of oil and if you're riding the bike when this happens you'll probably crash and I personally wouldn't want to be anywhere near the bike when this happens. Not quite as bad in your case since you've got a sidecar (hack). Definitely, you'll be shopping for a new engine.

"A stitch in time saves 9". Let's face it, your chain is audible. It's so sloppy it's hitting something now. Usually, you wouldn't get to this point before replacing.

Lol. Please don't concern yourself too much John - I wasn't thinking of riding it like this but I do have a curious mind and have the need to know these things, especially when someone dumber than me asks 'Why are you doing that for?'

I'll check tomorrow to see if I can hear the chain slapping as you suggested.

Yaegunp wrote: Here is the chain I spoke about and looks like a fair bit of slack there! Kudos to Kawboy as his unfailing ears spotted the noise as chain slap and it could be that he was right. I assume that I would be better off with a worn spindle than a stretched chain (if that's what it is?) I guess there is no way of remedying this without splitting the engine?

Chain Slack << Click Here

Oof. Yeah, that's going to need some attention. I'm trying to remember how much give there was to that chain (which, if I remember, connects the secondary shaft to the transmission assembly) when I had my cases split, but I highly doubt it was that much.

If you decide to remedy it, like was stated, it's not an overly difficult process, just pricey (mostly due to gaskets and the large multiples of certain parts, like piston rings). I'd grab a manual (or download one off this site), read it over a number of times, and then have at it. You'll need a cherry-picker lift for the engine removal, but no real special tools other than that.

If you end up pulling the engine and need some of the internal parts, let me know. If just the chain is bad, I think I've kept the ones you need indoors. If the shafts need replacement too, THEN you're chasing the correct size bearings to match both your engine cases AND shafts. I didn't have the correct tools to do this job myself, which is where I bit the bullet and just replaced my entire bottom end with a donor motor. Still, if you need parts and/or help, I'll do what I can to remember.

Fortunately, you seem to have found the source of the noise. Unfortunately, it appears to be excessive wear of the secondary chain. You can check the secondary chain play by removing the oil pan and measuring the slack (21mm maximum permitted)at the midpoint between the gears. If you are going to remove the engine and replace the chain, you must remove the oil pan anyway to clear the frame.

If the secondary chain has too much slack, you can be reasonably sure that the primary chain is also beyond the wear limits. The cases have to be split to measure it. Removing the engine and replacing the chains is not that terrible a job. Just take your time. Do one step at a time correctly and double check everything. The hardest part might be finding a new chain or chains. Maybe some are still in the Kawasaki dealer parts system. Perhaps there are some good used ones available, but you would have to check a used chain before actually placing it in service.

Excessive wear on these chains can be avoided by using the correct oil of the highest grade and changing oil/filter at the proper intervals. It is paramount to use a motorcycle oil with sufficient ZDDP and a high HTHS rating.

Good luck and please keep us informed of your progress.

From my machining years - lotsa in the oilpatch - worn shafts can usually be resurfaced quite readily. For up to .030"/30 thousandths the easiest is to build up with chrome, and grind to size. A good shop will have a good oven to relieve hydrogen embrittlement from the chroming process. Nothing special, and done all the time.
Lee in wintry Alberta.