Timing Chain, 72 link Part # 92057-1019 BF25H Roller Chain 72 link

biltonjim wrote:

Also, why did they think it was acceptable to have the valve timing influenced by primary chain wear?

 

My guess is the initial wear is designed in so that timing would be initially 'advanced', and after the chain 'stretches,' i.e. 'break in',  the advance is eliminated or reduce to fall within desired limits.   

biltonjim wrote:

Wouldn’t it be interesting to speak to the engineers who designed this engine? What was the thinking behind opting for the straight side plate chain? Also, why did they think it was acceptable to have the valve timing influenced by primary chain wear?
 

Hey Sorhicio, doesn't your brother own a chain factory?

Good stuff here. I spent time looking for replacements too.. but the post was deleted when the forum was upgraded.

Glad to read these chains are still available, even in a different 'Form'. BTW, FFF is a good concept.. hadn't heard that one before.

dcarver220b wrote:

Good stuff here. I spent time looking for replacements too.. but the post was deleted when the forum was upgraded.

Glad to read these chains are still available, even in a different 'Form'. BTW, FFF is a good concept.. hadn't heard that one before.

en.wikipedia.org/wiki/Form,_fit_and_function
Form , Fit , Function was developed in the 1960's and brought into incorporation Public Law to enable competition between suppliers. In Engineering, when developing an Engineering Change Control i.e. making a change to a system using alternative parts,  FFF is what drives the aspects to be considered when making a change.

Now back to our regular topic updates.

Armed with new information from a local chain supplier Tsubaki Chain has identified that the original stock chain is their product BF25H chain. 
I can buy this chain in 10ft lengths for $106 CDN. First,  that's more than I need. 18" is 72 links so 10 ft would make 6 chains.
The master link for this chain is $7 CDN and it's a clip style master link. I would prefer a rivet style since at maximum engine rpm the chain could be traveling as fast as 5000 ft/min.

I also did a search on EBay for BF25H chain and stumbled upon a listing for a Kawasaki cam chain to fit a 2006 Kawasaki KLN110 which is a scooter. The pic on the listing shows the chain which has the flat sided link plates and the original packaging with the label that reads "cam chain timing (Tsubaki) BF25H 88 link" and Kawasaki part # 92057-1116

I called the local Kawasaki dealer and asked for price and availability and it's still available . $33 CDN. I ordered one and it will be here Dec 28th.

It will require shortening from 88 link to 72 link and I think if I carefully remove 2 pins with my chain breaker tool and shorten the chain, I can reuse the 2 pins to rivet the chain back together. Not being cheap here. Just not in favor of a chain changing direction from straight to around a small sprocket at 5000 ft/min. Just a gut feeling.

On the off chance that Tsubaki sell rivet style master links, I've asked the chain supplier to inquire about that as well. We'll see.