Topic: 1977 CB550 primary chain opinions needed...

[vincentlefre]

Hi all,

I'm currently stripping the engine of my 1977 CB550F. I haven't split the cases yet but the oil pan, cylinders and head have been removed and the engine is out of the frame. I wondered if anyone can give me an opinion on my primary chain condition and whether it should be replaced. I've found no data on tolerences for backlash etc. There is some discernable side to side play and a little slack but I'm unsure of what is acceptable. I understand that if they are completely nackered the can hit the casing. Below I have posted a video showing movement and a photo of a small cut in the casing, though I'm not sure if this is from the chain as no amount of pulling around will make it reach this far in it's present state. Please note, these were taken with the engine on its side.

Any help would much appreciated.

[rb550four]

Has the primary chain left wear marks or worse on the perch for the timing chain tentioner?  I just replaced one in mine last weekend. They cost around $130, I threw in a new timing chain too because I was there anyways. I'd rather break it down once and trust the engine fully, rather than just change one part and wonder when I'll have to break the whole motor down again. Your chain looked slack to me, if it were in my crankcase, I'd change it.

[vincentlefre]

Thanks for the reply, will check if it's been rubbing where you suggested. I'll be replacing the cam chain too. I'm happy to spend the money but only if it's necessary.