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1967 CB450K0 Black Bomber Rebuild - By Royhall
K2-K6:
Very nice work Roy.
"Now here's the previously mentioned scare, it went straight to 7000rpm before I could reach under the tank to kill the ignition. Scared the crap out of me and my hands were still shaking 30 minutes later."
I bet that reduced the time for oil to reach the exhaust cam :o
royhall:
Well spotted Dave. I already rectified that since the photo was taken, strangely it was the photo that alerted me to it. Can you remember what voltage reading you got at the battery, static and with the engine running. My only concern there is that I have updated the wiring quite a bit so anything is possible. As for the oil pressure, it gave it a good leak test and nothing came out. As for blood pressure, well that went sky high.
AshimotoK0:
The best way to check if the system is charging it to put a multimeter on 10A DC range in series between the +ve battery terminal and the positive wiring BUT don't operate the starter as this wil draw too much current and pop the fuse in the meter. You will then see a positive value if the system is charging (at different revs) and negative value if it's not charging. I don't have any experience with those Motobatt batteries, so I can't really comment on those.
Your pattern silencers will definitely have been meant for a K0 as the K1 does not have the front mounting brackets. Don't ask me how I know this.... I bought a set of NOS 'K0' silencers, which turned out to be K1 (i.e no front brackets). If you look at the Bomber in David Silvers museum closely, it is fitted with K1 silencers with the front brackets bodged on and silver painted. Luckily I found some proper K0 NOS silencers and sold on the K1 ones.
One Achilles heel fault of the Bomber is the starter sprag clutch. On mine the retaining screws had come loose and chewed up the rear of the alternator rotor and also ripped out the stator windings. Also the sprag rollers had distorted and ruined the side plate. Plus the sprag clutch rollers had also badly worn the boss on the sprag clutch sprocket assembly. The parts are rocking horse poo parts. I have got my mate Graham Curtis looking at recovering the sprockets by grinding down the boss and shrinking on a hardened collar. I did get hold of a NOS CB500T --275-- rotor and it looks basically the same as the --283-- part (the taper is the same). People tell me you can fit the 5-speed parts but even these are very rare, even in the States. The ony place I have seen selling the clutch and alternator rotor relatively cheaply, in decent nick, is the seller on eBay called BGM Cafe racers.
There was a discussion on Facebook Bomber closed group on the starter clutch .. I will copy it later and put it on here.
royhall:
Thanks Ash will look forward to reading the Facebook thing as it may have some useful information.
I have taken the starter clutch back out and degreased everything. It was covered in some greasy goo that I think came off the new starter chain. I thought that may have been the problem but no luck as it was just the same.
After cleaning I miked everything up to check for maybe an odd roller but didn't find anything. I have assembled it on the bench and tried it, one of the rollers sticks out of position every time I tried it. Under a magnifying glass the roller mating face has two dents that are grabbing the roller and stopping it moving. All three faces have this wear but one is worse. Really this part requires replacing but they are available nowhere.
My plan for tomorrow is to polish the faces with a small fine polishing stone and try to remove a bit of material at the high spots to take away the dent and see how that works. I have nothing to loose if it doesn't work as it's useless as it is. If that doesn't work, to be honest I don't know what I will do. I doubt I will find a new or good used item as there are so many people looking. I was hoping that someone would have come up with a cunning plan to remedy this as it's a very common problem. All I can find on the internet is how to replace the rollers and springs. One lucky break is the roller face on the sprocket is in good condition.
Any ideas here would be gratefully received. Cheers.
UPDATE. Just noticed something here https://www.cmsnl.com/honda-cb450k0-black-bomber-general-export-usa_model14564/rotor-ac-dyn_31101283013/#.X7lX7-VxeUk This alternator rotor has lugs to centre the starter clutch, mine does not have these. I was wondering how it was supposed to centre as the starter is bolted down before the rotor is on the shaft. If its even slightly off centre it's going to cause a problem? Probably wont help as these items aren't available either, but looking at mine it does look like some arse of a PO has filed the lugs off. Looks like I need a replacement rotor before moving on.
Spot the difference. No wonder the starter wont work.
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K2-K6:
Wondering if there are any close that could be machined as the basic design has mostly been copied from those early Honda I believe.
https://www.ebay.co.uk/itm/Anlasser-freilauf-Starter-CLUTCH-Yamaha-VMAX-1200-V-MAX-Kupplung-VMAX12-/111619692053
Is it the component in above link?
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