Topic: 750 thread on petcock

[Ernest]

The tank that came on my 750 had a petcock that threaded on and only had one nipple.  After the long process of getting the running and a new motor later, the bike would run great then putter out, It was being starved for fuel on one side of the carbs.  I had one fuel line off the petcock with a T splitting the line to each carb supply.  I was thinking the carbs would pull fuel from the tank but the way I had the lines at the T I could not get fuel to one side fast enough.  Unfortunately I even spent a couple hundred getting this tank painted only to find out it's not working properly with the bike.

To solve the fuel issue I had to get a new stock tank with a petcock that has the two nipples and is attached to the tank by the two screws.  The bike runs great now but my question is where in the hell did this tank come from and what year 750 had this style of petcock, or is this tank an after market odd ball?  It was spray painted when I bought the bike and underneath the spray paint I found a metallic purple but no decals on the sides. 

[Roach Carver]

the early tanks had a petcock with a sediment bowl. that  petcock was held on with two screws. the later models were held on by a nut. not sure about the years though.

[Jonesy]

This worries me.. I'm about to paint a tank for my 750 and it's the newer single-tap petcock. 

Here's info on the change:

[mkramer1121]

You could have saved your money on the new tank.  I know z1enterprises sells a high flow Pingel pet cock and adapter plates to fit our bikes.  I have one on my 550 and it works great.

[cbjunkie]

http://www.z1enterprises.com/reference/petcock.aspx

[mkramer1121]

Yeah, thanks junkie, I should have included that.

[Clyde]

My 750F1 only has one outlet with a T-piece in the line to feed the 1-2 and 3-4 carbs.
This is standard for the F and F1
Clyde

[nteek754]

Hey all  I think you just didnt have the lines run right  for the T to work correctly  like someone else said they were were stock on the late model 74s  Sisters bike and  on the 75 76s this may sound petty but might try a Y and not a T I know there is a way to make it work been there done that  I run a 73 750 with the sediment bowl  but built a chopper two years ago and got  one line feeding  the foue carbs with plenty of fuel good luck  dont trash the  tank  Craig in Maine  seven fifty four ever

[Superbiker_uk]

When i built my Dunstall I had to ditch the old K2 tank as it was beyond economical repair. I picked up a later tank (K6 for the UK) with the fuel tap on the left hand side. At that point i was not aware of the two pipe to one pipe modification and so laid out £37 for a new tap from David Silvers. When it arrived I of course noted that it only had one nipple for the fuel pipe. However, the casting is such that you can modify the tap and fit another nipple. The brass nipples are an interference pressed in fit so I pulled one from my old K2 fuel tap and then drilled a suitable hole in the new tap casting (very carefully ) and pressed in the nipple. I was then able to connect with both pipes and I get great fuel supply to the carbs without any problems. I only wish I had photographed this when I did it as you can not see the modification very well with the tap and tank mounted. I hope you get the idea though. If you look at your new tap casting I think you will see what I mean as to the location for the additional brass nipple.

[Ernest]

I tried as many ways as I could think using the T to no avail.  The single nipple left side petcock just came down too far and the lines would have to snake down then up through the holes in the carb base plate to get to the carb nipples.  The two nipple right side petcock tank works so much more efficiently.  I had dinged and chiped the paint on the tank I had painted anyways so I'm sick of having to worry about a paint job...I rattle canned this new tank flat black and I'll worry about looks when all other things are restored.

thanks