Author Topic: 1975 CB500K1 crank rotation resistance  (Read 829 times)

Offline Bryanj

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Re: 1975 CB500K1 crank rotation resistance
« Reply #15 on: May 05, 2024, 04:50:25 PM »
Yes they can, and were, back in the day we had one with a bent crank and taking the chance that it was maleable cast we had an approx 9 inch long bar turned so that an internal taper locked to the crank with an ht allen screw then carefull "whacked" the end with large hammer whilst clocking the bar on a turned portion concentric to the taper.
We got it to within 1 thou of concentric and the engine ran fine for as long as we had records of it(years)

Offline martin_uk

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Re: 1975 CB500K1 crank rotation resistance
« Reply #16 on: May 08, 2024, 11:06:16 AM »
Its apart again.

Checked crankcases for distortion and found that approx 6 thou out at no.1 main journal housing face of upper case.

There is a lever mark on the inside face of alternator rotor and had not been removed by PO.

It came off fine with threaded bar screwed in to end.

Wondering if PO levered a bit too hard on case.

I am also going to check the mains run out with V blocks and surface plate.

Any experience of crankcase face distortion?
1977 CB750F1
1977 CB750f1 836
1978 CB750F1
1975 CB500K1

Triumph Street Triple 675R
Ducati 800 Icon Scrambler
Triumph 3TA
AJS 350 mod16
BSA BantamD1
Honda C90zz
Honda CB500X
BSA WD B40 350

Offline Bryanj

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Re: 1975 CB500K1 crank rotation resistance
« Reply #17 on: May 08, 2024, 11:48:21 AM »
Sounds like somebody didnt find the hidden bolt(s)
I may have some cases with crank, not sure

Offline McCabe-Thiele (Ted)

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Re: 1975 CB500K1 crank rotation resistance
« Reply #18 on: May 08, 2024, 12:13:50 PM »
That's a real pain - at least you have found the issue.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

 

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