Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: 750rideruk on September 02, 2020, 05:00:04 PM

Title: 750 K1 grumbling gearbox
Post by: 750rideruk on September 02, 2020, 05:00:04 PM
My 72 UK K1 has developed a grumbling sound from the gearbox while idling. I know about the primary chain noise so it is not that sounds a bit like a bearing. Bike has done 70K miles any ideas? sounds like it could be expensive.
Title: Re: 750 K1 grumbling gearbox
Post by: Bryanj on September 03, 2020, 03:42:48 AM
If its a bearing you wont know till you split it, i think they are all available from Yamiya in Japan(the ones with grooves are "specials" and not available from bearing suppliers)
Title: Re: 750 K1 grumbling gearbox
Post by: Trigger on September 03, 2020, 07:38:58 AM
The output bearing is the first one to go on early 750's. Honda redesigned the crank cases to take a larger bearing on the K2 onwards.
50 year old bearings and 70,000 miles ! It is time for a full change of all the gearbox bearings and as Bryan has pointed out that it is lucky that they are all still available  ;)
 
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