Running a twin petcock on a 4 cylinder

[cervix a lot]

Hey guys sorry if this has been asked before, but if it has been I couldn't find the right combination of words to search for it.

I plan on running a CB500t tank on my 77 CB750 but the problem is that the 500t petcock has two brass tubes to run fuel lines where as my 750's petcock only runs one. I was wondering if there was any way to either block off one of those tubes or if any of you had any ideas on how to run that petcock on my bike. Any help you all could provide would be greatly appreciated, thanks in advance!

Cheers
Andrew

 

[Tune-A-Fish]

Run the two into a Y and onto the carb, is one for reserve or one for each carb on the 500T... could be a volume issue if you run only one... the CB750 aint no economy machine.

 

[Hurco550]

Could be wrong, but I seem to remember the 500t being different. I thought one was a vent or something. On cognito moto 550 he only ran off of one side. Look for his "winter project" thread. I think he hashes it out

 

[Tune-A-Fish]

Nope... Dual fuel line, Devin must have closed one side off internally or it was not a running motor in the pic. Looks like if you wanted you could run the 750K petcock on it if the holes line up.

 

[cervix a lot]

thanks for all the replies, I tried running the 750's petcock on the bung of the 500 but it seems as though the 750's petcock was smaller. I will look into running the Y-connector though, I tried running a T-connecter and there was no way to do it without a serious bend. I wouldn't be opposed to blocking off one of the tubes, do you think the carbs would get enough fuel run to them for it not to be a problem though?

 

[Tune-A-Fish]

The Y will prevent an air lock also, but I think the line size looks the same, look over the 750 chunk inside and see if the 500 has any restricted flow in comparison, if not get a block off nipple and spring clamp.

 

[Hurco550]

This is what I was referring to, I digress

So thinking about my carbs after a week of frustration and it dawned on me that my tank is from a cb500t twin and the petcock is from the cb500t which has two separate carbs and that's why my petcock has two outlets. Not thinking about it I ran two separate hoses from the two outlets into the two inlets on my carbs. Well... One is an inlet and the other is a breather. Unplugged the breather tube from the tank and no more leaks! Dumb dumb dumb...

 

[Tune-A-Fish]

Oh yeah... that would not be good, but I wonder what vent line he was referring to.

 

[Tune-A-Fish]

Nevermind, he's talking about the breather from the valve cover, but where did he plug that sucker in lol