Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: kazzy on January 31, 2010, 04:37:04 PM

Title: PISTON NEEDED FOR 1976 CB750F1
Post by: kazzy on January 31, 2010, 04:37:04 PM

HI .I,AM DESPERATE FOR A STANDARD SIZE PISTON FOR 1976 CB750F1. CAN ANYONE PLEASE HELP :)

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: mad mike on February 03, 2010, 08:54:59 PM

hi kazzy,re.f1 piston, are you after new or used, ? mike

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: kazzy on February 05, 2010, 06:10:23 PM

HI. MIKE, I REALLY DONT MIND WHICH, BUT I FOUND A CONTACT WHO HAS DEALT IN HONDAS FOR 35 YEARS. HE TOLD ME THAT I HAVE F2 PISTONS IN MINE, HE ALSO SAID THE EARLY F1 HAS K6 PISTONS IN IT. SO IF YOU KNOW OF ONE I WOULD BE GREATFUL

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: Spitfire on February 05, 2010, 06:46:56 PM

Be very careful, the F2 pistons are domed and the F1 pistons are flat, I would not like to try and run F2 pistons in an F1 ! Bye Bye valves
Have a read of this http://forums.sohc4.net/index.php?topic=49659.0

Cheers

Den

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: AshimotoK0 on February 05, 2010, 10:10:31 PM

I have these but not sure if they are F1 type. they have 392 on the Skirt and HONDA  ( approx.1.1mm top ring)

Also, see      

  http://forums.sohc4.net/index.php?topic=57528.0

The piston in the background is also a 392 but has the thicker rings  and different top profile - pretty sure its off a K7

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: Spitfire on February 07, 2010, 09:13:11 AM

Have a look here http://cgi.ebay.co.uk/nos-honda-cb750f-cb750-piston_W0QQitemZ370323277455QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item5638fcc68f

Cheers

Den

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: AshimotoK0 on February 07, 2010, 12:26:55 PM

Quote from: Spitfire on February 07, 2010, 09:13:11 AM

Have a look here http://cgi.ebay.co.uk/nos-honda-cb750f-cb750-piston_W0QQitemZ370323277455QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item5638fcc68f

Cheers

Den

They don't look like the F1 pistons that I have - maybe they changed during F1 production.  Again see

http://forums.sohc4.net/index.php?topic=57528.0

Ash D

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: Spitfire on February 07, 2010, 12:54:45 PM

I have heard that the F1/77K used 2 different pistons both 392, the eBay one looks just like the ones in my F1, there was a thread on the US site about 392 pistons, here's a photo of the two side by side,
http://i233.photobucket.com/albums/ee84/RxmanGriff/Honda/P1020789.jpg
Maybe it is the same article you are thinking about but the US site seems to down at the moment, so I couldn't check.

Cheers

Den

Title: Re: PISTON NEEDED FOR 1976 CB750F1
Post by: AshimotoK0 on February 07, 2010, 01:39:40 PM

Yes it is the same article but the US site down.

I have both types.

On the photo of the parts which  I have the one you can just see in the background is a 392 but I am sure is off a K7. The others came from an F1 motor I got to rob the crankshaft from for my K0 The F1 Engine no was  CB750E-2545740 . I do have the head from it too but it has a small mark on the ring around one of  the combustion chambers and also the barrels but one has slight corrosion on the top of one of the bores, as the motor was left standing for yonks.