Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: RGP750 on October 06, 2015, 02:19:52 PM

Title: K0 Head Gasket
Post by: RGP750 on October 06, 2015, 02:19:52 PM

Hi Guys
Trying to track down a K0 Head gasket.
(one bolt hole on the center line) or do you bodge it with sealer.
(i know i wouldn't be happy with that either.)
Anyone know a decent supplier?

Title: Re: K0 Head Gasket
Post by: Trigger on October 06, 2015, 02:45:04 PM

I think they ran out in 1975, one that will do >http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2055119.m570.l1313.TR0.TRC0.H0.Xcb750+K0+head+gasket.TRS0&_nkw=cb750+K0+head+gasket&_sacat=0>>

OR £90 from a German supplier ;D

Title: Re: K0 Head Gasket
Post by: RGP750 on October 06, 2015, 03:02:27 PM

Saw that Trig but it has 2 holes ,do you just bung it up.

Title: Re: K0 Head Gasket
Post by: Trigger on October 06, 2015, 03:04:45 PM

That bolt hole does nothing on the K0, just leave it or put a dob of sealant  ;)

Title: Re: K0 Head Gasket
Post by: RGP750 on October 06, 2015, 03:09:12 PM

Ok Ta

Title: Re: K0 Head Gasket
Post by: Trigger on October 06, 2015, 03:17:31 PM

The OEM gasket was superseded in year dot to the 307. Was a young boy the last time I see a 020 ;D

Title: Re: K0 Head Gasket
Post by: AshimotoK0 on October 06, 2015, 03:19:33 PM

Think the K1 that Pete has, the seller (sandcast guru)  used the later gasket and fitted O rings for extra sealing. Honda issued a bulletin on it and sold special square section 'o'rings as mentioned in the bulletin. I bought some Viton ones as used on Pete's K1. If I have not given you some already, I can dig you  out a set.

Its SB #42 Cylinder Head Gasket Oil Sealing but it was removed from the SOHC4.net site

Original SB 'O' rings 12115-300-305

http://www.ebay.co.uk/itm/NOS-Honda-OEM-O-Ring-CB750-12115-300-305-/191011621578

see http://forums.sohc4.net/index.php?topic=63310.0

Maybe a quad ring seal would be more like the original Honda ones. I will investigate  Rich

This is from the guy who sold Pete his K1

"Yes, you can use the later "large hole" gasket on the early engines, but be aware that you are actually creating a small cavity that oil can sit in at the head / barrel joint around the 8 drain studs. On the odd occasion that I have used these later gaskets on early engines, I have fitted 8 "o" rings of an appropriate size from an engineering supplier to effect a seal.
Any later K series barrels will go onto a '69 motor, but as you say, you just have that "spare 6mm threaded hole (which can't really be seen anyway once built up sandcast). It is only obvious that later barrels are fitted if they are the late K1 and onwards die cast type which have a different fin profile at the ends."

Title: Re: K0 Head Gasket
Post by: AshimotoK0 on October 07, 2015, 08:19:36 AM

Here goes with the SB 42 Rich

Brilliant link here BTW

http://greenbushacres.ca/Motorcycles/Technical/Technical.html

Title: Re: K0 Head Gasket
Post by: Trigger on October 07, 2015, 12:37:57 PM

Top man Ash, have not seen that link in years.

Title: Re: K0 Head Gasket
Post by: RGP750 on October 07, 2015, 12:45:08 PM

Thanks Ash great info.