Topic: petcock won't clear the carbs!!! ('71 CB750 Dunstall tank)

[ksmith0034]

Now what do I do?  Btw, the tank is pushed all the way up onto the rubber mounts.

[Kong]

Move the mounts (on the frame), it will be a lot easier than moving the petcock.

[ksmith0034]

Yes, but the tank and seat are already fabbed with 2 zeus fastners on the seat that holds the whole thing together.  I think there are pictures on my build thread.
With that being said, I don't know if there is any other way around this problem...

[seanbarney41]

Get a pingel or other petcock that clears.  Z1 Enterprises has nifty kits fo rmounting non-stock petcocks.  They also have inexpensive aftermarket petcocks and fuel valves.  Maybe just an in-line fuel valve could be used with a more standard plumbing type tank outlet.  Yup, you're gonna have to get crafty and creative to avoid cutting up either the tank or the mounts.

[srook]

The tank mounts should be removable on the original Dunstall tank.  You might be able to modify the mounts to give you the extra room for the petcock to fit.  Maybe oval the holes in the mounting brackets so you can slide them back.  It's hard to tell from the pics but is the body of the petcock interfering with the carb linkage or is it the 2 spigots on the back of the petcock that are in the way?  That tank may have been mounted to a CB500/550 or to a K0 originally which is giving you problems now.
Scott

[srook]

Hi Kevin,
I got some better pics of the mod to the carb linkage for my Dunstall tank.  These may help.





Scott

[ksmith0034]

Thanks for the pics Scott.
As for moving the tank forward... I already need to do the steering stop mod to keep the clubman bars from hitting as it is.  If I go forward any more it will be even worse.  I will definately check out Z1's options - I love that place!

[754]

In the first pic the petcock looks crooked, ie not parallel to the backbone.. and I cant see where it hits.? is it on reserve it hits?

 This may or maynot solve your problems, try a set of PD accelrator pump carbs if you can test fit a set.. nothing moves on the top of them while in operation..plus they have a squirter..

 +1 on the pingel maybe giving clearance..

[ksmith0034]

It looks crooked because I had to set the tank on crooked to get it to clear the carbs for the picture.  It looks like a different petcock/adapter might be the only viable solution.

[beaniam]

I ran into a similar problem with the 83 nighthawk tank petcock on my 78k.  I was able to just take the petcock off, stick a steel rod down in the petcock hole and gently bend it out in the direction I needed for it to clear.  In the end it pivoted the petcock away from my frame over an inch.  Might give you enough room.

[ksmith0034]

I ran into a similar problem with the 83 nighthawk tank petcock on my 78k.  I was able to just take the petcock off, stick a steel rod down in the petcock hole and gently bend it out in the direction I needed for it to clear.  In the end it pivoted the petcock away from my frame over an inch.  Might give you enough room.

I can't do that on this tank - it's fiberglass with an aluminum insert for the petcock.  It either bolt on where it was originally designed, or ...  That's the part I can't figure out.  There just isn't any room!!!  I may need to find some kind of remote petcock solution if one even exists.
This stinks because it's the ONLY thing keeping me from riding this bike for the first time!