Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: Johnny4428 on July 28, 2021, 05:07:01 PM

Title: Knock pin.
Post by: Johnny4428 on July 28, 2021, 05:07:01 PM: Anybody come across knock pins being too long between cylinders and cylinder head part No 9430112220.
I can easy shorten them but what length are they supposed to be? I had new ones from CMS as listed for 750k3, but they are just too long.
Title: Re: Knock pin.
Post by: Nurse Julie on July 28, 2021, 05:16:59 PM: I have them in stock in trade packs Johnny. The parts book is wrong 😊😊😊😊

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Title: Re: Knock pin.
Post by: Johnny4428 on July 28, 2021, 06:08:53 PM: Thanks Julie, I have one stuck in one side, and I could tell it was a good bit shorter by what was protruding above surface. Iâ€™ll have a go at shortening one of the new ones I have. Cheers.
Title: Re: Knock pin.
Post by: SteveD CB500K0 on July 28, 2021, 06:14:35 PM: Are they really called â€œknock pinsâ€?

Whatever does it mean?

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Title: Re: Knock pin.
Post by: Nurse Julie on July 28, 2021, 06:17:31 PM: Quote from: SteveD CB500K0 on July 28, 2021, 06:14:35 PM
Are they really called â€œknock pinsâ€?

Whatever does it mean?

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A pin that you knock in 😊😊😊😊
Title: Re: Knock pin.
Post by: Johnny4428 on July 28, 2021, 07:06:53 PM: Julie, I have measured again and my pins are not far off the same size as yours which are too long. I have measured the recesses and I wouldnâ€™t put anything greater than 20mm for fear of either poor seal or worse a warped head. I had a root about in old 750 parts that I removed and found a pin 18mm in length, I would say that is the same as the old one that I didnâ€™t manage to remove. Iâ€™m not sure why this should be, even if the head has been machined itâ€™s not going to be mm off it itâ€™s going to be thousands. Any ideas?
Title: Re: Knock pin.
Post by: ka-ja on July 28, 2021, 07:07:51 PM: Called "dowels" in engineering and not necessarily hollow tubes.
Title: Re: Knock pin.
Post by: Johnny4428 on July 28, 2021, 07:21:26 PM: Yes well thatâ€™s what I would call them if I hadnâ€™t studied the parts list. I reckon Iâ€™ve got a cylinder head off a newer model that uses 18mm dowels/â€œknock pinsâ€ 🤣
Title: Re: Knock pin.
Post by: Nurse Julie on July 28, 2021, 07:31:09 PM: Quote from: Johnny4428 on July 28, 2021, 07:21:26 PM
Yes well thatâ€™s what I would call them if I hadnâ€™t studied the parts list. I reckon Iâ€™ve got a cylinder head off a newer model that uses 18mm dowels/â€œknock pinsâ€ 🤣
Give us a few minutes Johnny, I've got Graham on the case having a measure up.
Title: Re: Knock pin.
Post by: Nurse Julie on July 28, 2021, 07:41:29 PM: Grahams had a measure and you need 12 x 18mm (the dowels actually measure a tad under 18mm)
Title: Re: Knock pin.
Post by: Johnny4428 on July 28, 2021, 08:31:57 PM: Thanks Graham and Julie. I ordered new ones because I had an idea I was going to knacker them taking them out but decided to leave the one in and managed to remove one. So I actually have the one that came out which is useable. Thank god I didnâ€™t try and use the 22mm one!
Title: Re: Knock pin.
Post by: Nurse Julie on July 28, 2021, 08:52:32 PM: Quote from: Johnny4428 on July 28, 2021, 08:31:57 PM
Thanks Graham and Julie. I ordered new ones because I had an idea I was going to knacker them taking them out but decided to leave the one in and managed to remove one. So I actually have the one that came out which is useable. Thank god I didnâ€™t try and use the 22mm one!
Yes, crisis averted there Johnny... Onwards and upwards 😊😊😊