Honda CB750 Sandcast

The Restoration Shop => Fuel (gas - petrol) Tanks, Side Covers and Air Box => Topic started by: Sgt.Pinback on January 29, 2017, 07:36:09 am

Title: Pet cock (long version) differences
Post by: Sgt.Pinback on January 29, 2017, 07:36:09 am
Have two different pet cocks.

Which one is earlier/later version?

Thanks
Title: Re: Pet cock (long version) differences
Post by: Steve Swan on January 29, 2017, 03:40:55 pm
Uli,  are you referring to the differences visible between the 2 fuel taps shown ?  i am not sure what differences you are referring to.

i don't think you are asking if there appears a visible difference in the length of the neck of either fuel tap ?

the only oem replacement taps i have seen produced by Honda are the long necks.  and i have noted there are subtle differences between these taps manufactured in the various decades of their manufacture.  is it these differences you are asking if "earlier or later" ?

if so, i do not know the differences in taps manufactured during the different decades of manufacture.   i do have a few long neck taps at my shop that i believe are probably original period first manufacture, but i have not looked at them closely to the newly manufactured oem Honda taps currently available.

for what it might be worth, the actual website shows the differences between short and long neck taps  - http://cb750sandcastonly.com/support12.htm#Fuel (http://cb750sandcastonly.com/support12.htm#Fuel)  The differences in neck length are obvious.  pics of the loose taps were submitted by Al Landry over 10 years ago.  the pictures of the taps on blue and green tanks are 4363 and 232 respectively.  i am not aware the factory produced replacement parts short necked taps.  
Title: Re: Pet cock (long version) differences
Post by: Sgt.Pinback on January 29, 2017, 03:48:36 pm
Yes.

Those in tbe pics are both long neck but I don't know which one to take for my sandcast (I don't need a short neck for mine).


Title: Re: Pet cock (long version) differences
Post by: Steve Swan on January 29, 2017, 03:55:11 pm
ok.  i got it.  i amended my first reply to you.

if no one has a definitive answer to your question, i can look at the taps i have for any possible difference.  i believe these taps are original period manufacture.   

i have never paid any attention to any possible differences between an oem long neck tap found on a 69 model in contrast to a 1971 or later model....

nor have i paid any attention to any differences found on original period manufacture long neck taps and later manufacture taps......

sorry i can't be of more help !
Title: Re: Pet cock (long version) differences
Post by: Sgt.Pinback on February 13, 2017, 01:12:23 pm
Any update on this?
Title: Re: Pet cock (long version) differences
Post by: Steve Swan on February 13, 2017, 10:18:51 pm
sorry Uli, for not getting back to  you.  i looked at taps i have, they are both types and i don't know what machines they were removed from.  i replaced the tap on 2157 and replaced it with a new one.  i don't know what the original looked like.....  and 232 has a short neck, so i'm not much help there either......  if looking at the pictures on website of a short neck could help, you'll see what the back side looks like.  i'm going to guess the tap on the right in the first picture you posted is an earlier version because it looks like what one could expect to see with an earlier manufacturing process.  again, a guess.
Title: Re: Pet cock (long version) differences
Post by: DW69K0 on May 20, 2017, 05:59:08 am
Look for a date stamp on the back of the original petcock with a 4 or 44 stamped on it, best way that I know how to tell the earlier long neck petcocks.
Best,
DW