Topic: convert cb750 petcock to two outlets

[jason41987]

i just bought a petcock for a CB750, i posted a photo below to show which one it is i purchased, my intent was to use a tee with this, but it would appear theres a second hole that looks like it could be adapted for a second nipple or whatever you call that brass piece..

would it be possible to modify this throttle body for two outlets?

http://www.cb750supply.com/parts/480/20-8038.jpg

[lone*X]

I've wondered the same thing.  Hopefully someone has already converted one and will speak up.

[ekpent]

Just curious as to why worry on it.Would it be for looks or a more practical reason. The later model 75 and 76 750 K and F's have used the tees for years with no issues.

[754]

 My thought is that the hole in the body is probably tapered, the brass barb that we just measured out of a Suzuki , is tapered..pretty sure they all are.
 So if you convert it yourself, and it works loose it could at best get messy..after that it gets worse. Like. I mentioned to the Suzuki guy, if it lets loose in your garge, its gonna stink..if the pilot light lights the fumes, you loose all your bikes, and maybe your garage.. So we made his elbow out of one piece..way more work but safer.

[754]

 The piece in the pic started off like on the right. Then roughed out the hose barbs, they were then turned round with ridges to hold the hose. The rectangle section, then had an o ring groove milled into it. It replaces the petcock to give greater carb clearance on an SRX..

[jason41987]

it just looks like the petcock was originally supposed to have the two outputs and looks relatively simple to install one but i cant be sure, if it was just a matter of drilling something out, tapping and threading in another piece or pressing it in and soldering it, sure.. but if its more work than that then it wouldnt be worth it

[754]

 Actually if you reamed it, then made a barb with an interference fit..it would probably work.. It involves precision fitting

[jason41987]

what about getting it to flow fuel through that barb? theres a hole where the other barb would be, is there a tube inside it or something?

[754]

Should be a drilled passage

[jason41987]

do you have some kind of schematic of the part i could look at?

[754]

 Youbtake it apart and look inside.. And it would be a drawing..not schematic.

[Rigid]

Like 754 says, it is an interference fit.  The Honda outlet tube is retained with nothing more than friction.  I have had them pull out instead of the hose pulling off.  A slight beading of the end and they press back in securely.  Solder won't stick to the cast aluminum and if your handiwork worries you, turn the thing off each time you park it. Consider how it was cast and drilled to begin with, look inside, and remember most inexpensive machining is in a straight line through castings.

[neilc]

the one i am using on my frisco tank has two outlets,i use a small in-line filter on each line,that feeds the carbs,one barb feeds #1&2 the other 3&4

[jason41987]

i looked through the inside of the outlet thats on there, and inside the hole where another outlet could go, its deeper inside the one with the outlet on it... then i looked at a part diagram for my bike which uses an identicle petcock to this one, but has a two prong outlet and apparently the actual valve part doesnt go that far back... so there is no sort of tube or anything inside it

this means i should be able to simply drill through, and put another barb inside.. but then again when i think about it, there had to have been some reason honda stopped using a two barb petcock?.. had to have been some reason

[754]

 There is reason, they saved a buck a bike....

[jason41987]

really? it was cheaper to add a tee than it was to add a barb?...

ill see if i can find a couple thread-in barbs and a matching tap at my local hardware store... then i wouldnt have to worry about them popping out either