Cam carrier damage.

[Woodside]

What was that company that used to metal spray surfaces like that, and then machine them down?

Joy Engineering?  Think they went bust.  Must be someone else....

Phill joy engineering

Still about and race tuning Hondas ....

[royhall]

Yeah I am expecting a hit from import duty etc. The bottom line though is I just could not find a good used one anywhere else. There's a few on a Dutch breakers site but the caps are missing and as you know they are line bored so without the original caps they are just scrap. Are these things possible to repair at any sort of affordable price, because these will start to become a major headache for CB750 owners pretty soon. Back to the 1000 mile oil change regime I guess.

[AshimotoK0]

I do have one of those used & spare somewhere but it's from an F1 I think or possibly a K7. I never sell anything on here I always give stuff away free, that I don't ever envisage using myself,  but that's a part I can't really do for free as it cost me decent money and I was saving it for a 'rainy day'. No idea what one is worth. Any ideas you old sages on here or if it will fit the F2 model?

It may take a bit of finding too but I have definitely got one spare somewhere. The cap markings match those on the carrier, so no worries there.

Cheers . AshD

[royhall]

Did a bit of research on that. Looks like its the same part number from the K2 to F2 but I guess there could have been a delta change during that amount of time, who knows. Taken a chance on the American eBay part as it looks identical and in good nick in the pictures. Seller says its good nick as well. If it turns out to be junk when it arrives, I would be happy to pay you for the part Ash, no problem. I know what you mean about a rainy day part though, these things are now rocking horse to find and its going to get worse as the used parts get used up. Did find a few new ones on the net (all America) but they were 250 dollars upwards. Hopfully some entrepreneur will jump in and re-manufacture.

[Bryanj]

They can be repaired, you can still ring this evening if you want ideas

[AshimotoK0]

In the Classic Bike  400/4 resto. article they found that a PO had  used Kawasaki shell bearings for a damaged cam bearing  head repair. Also at least on the CB750 they have 'carriers'. Decent  of Kawasaki to fit shells to the cam, why couldn't Honda do that.. Don't know which model(s) though. Same thing with Honda little ends on con rods.

Cheers ... Ash

[Bryanj]

love to know how they got the machining done as there is no hole to line bore

[bike-pusher]

The shells might have been crankshaft shells or big end shells from a smaller bike.  I'd also like to know how they did it.

[AshimotoK0]

The shells might have been crankshaft shells or big end shells from a smaller bike.  I'd also like to know how they did it.

No I looked them up and they were cam shells. possibly like these.

http://www.ebay.com/itm/Kawasaki-Z1-Z900-Z1000-camshaft-bearing-shells-/331289806403


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Cheers...Ash

[bike-pusher]

Oh, right, from a Z1/900.  Interesting, because I've had a number of Z550s/650s/750s and they didn't have separate shells.

[AshimotoK0]

Oh, right, from a Z1/900.  Interesting, because I've had a number of Z550s/650s/750s and they didn't have separate shells.

David from Saisei is a Z900 owner and confirms they have cam shells. I had a KZ650B1 and don't remember it having shells but I never stripped the engine. Bit like the CB750 has cam carriers but on the 500/550/400-4,350-4 the cam runs straight onto the alloy head/cam, cover. Interesting on the Classic Bike resto, someone had fitted shells into the the head but fitted a new cam cover without shells. Surprised that the 400/4 head and cam cover were not line bored as a matched pair. There again the 250/350K twin crankcases were not matched and were  sold individually.

Cheers ... AshD

[Bitsa (Ralph Wright - RIP)]

Have to say like that idea kawaski did but in all my time never seen it
Cheers
Bitsa

[AshimotoK0]

Have to say like that idea kawaski did but in all my time never seen it
Cheers
Bitsa

Let the Good Times Roll !!     Those shells look like they are nine quid each but how much would a head and cover be ! I seem to remember the CB72 had ball races for the cam bearings. Then the 250K had plain bearing 'covers' as did the CB160/CB175/CD175 then the CB750 with carriers then the dreaded smaller fours with cam running directly in the head. Think the 250G5 was like this too. Not sure about the CB500/4 as I never owned one, which is a real shame.

Cheers .. AshD

[Johnwebley]

the CB500-4 has the cam running directly in the head

[royhall]

The problem with the CB750 was in the original design spec. The designers were told in the mid 60s that the CB had to be in the USA showrooms at the same price or less than the Triumph Bonneville. As a corporate decision it was a master stroke that almost single handedly broke the British bike industry. But from an engineering point of view it left the CB hopelessly compromised ie. cheap to manufacture. Hence the plain main/big end bearings, no shells for the cam, small ends straight in the conrods, plain primary chains, a frame that wont allow cam cover removal etc, etc. The Kawasaki 900 engine was designed to be the the best it could be (with 70s technology) and was far more expensive new than the CB. This cheap and simple engineering is what we are now fighting against 40 years on.