1961 CB72 Project

sarals · Post by **sarals** » Tue Jul 01, 2014 12:44 pm

Graham, it's great to see you enthused and moving ahead!

Oh, not only do I wish I had a lathe, but the knowledge of how to use it. :)

G-Man · Post by **G-Man** » Tue Jul 01, 2014 5:25 pm

Sara

I'd willingly give lessons.... !

Next mini project - Oil pump restoration. I have made a jig for my milling machine and have some oversize gears. I am using the jig to re-machine the pump body with larger diameter wider gears to restore the clearances and improve the output.

jig in miller by graham.curtis, on Flickr

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sarals · Post by **sarals** » Tue Jul 01, 2014 11:28 pm

Pretty cool, Graham!

I'd love to drop by for lessons! It's the drive that would be hard, though. :)

G-Man · Post by **G-Man** » Fri Jul 04, 2014 2:07 am

I've been sorting through valve gear to try and assemble a good set for this project. I now have a nice cam sprocket - the big heavy one - and a pair of matching camshaft halves.

Camshaft.jpg by graham.curtis, on Flickr

What I am not sure about is the rockers. I know that early Dreams had the early type lighter rocker but I am not sure about the CB72. Neither of the two heads that I have dismantled had the early type rockers and only one had the big sprocket anyway. So which is it to be?

rockers.jpg by graham.curtis, on Flickr

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SMBH · Post by **SMBH** » Fri Jul 04, 2014 3:03 pm

Well I would go for the lighter ones always best to have less wight on moving parts.

Something I have noticed on my CB77 is the side play on the rockers they all have different clearance's with one of the exhaust's being the one with the most side play is this a problem as I still have my tinkling sound under load and when I close the throttle then it stops it's not tappets have checked them several times all are 4 thou a new cam chain sprocket so not the rivets) .

You meet the nicest people on a Honda I me young G-MAN and a jolly nice guy, not that young realy.

G-Man · Post by **G-Man** » Fri Jul 04, 2014 4:02 pm

SMBH

It was a pleasure to meet you! Thanks for the comment. I'm still not sure.

I'm wondering if Honda beefed up those rockers for a reason. Alan Curtis is currently stripping his 1961 CB72 head which looks pretty standard. I am looking forward to seeing his head fully dismantled.

I dismantled a CB400 head once and someone had done a lovely job of shimming all of the rockers so that there was no end float at all. It made the top end much quieter.

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sarals · Post by **sarals** » Fri Jul 04, 2014 11:31 pm

Graham, what's the thinking behind those heavy counter weights on that cam sprocket?