Topic: Dunstall Tank Petcock - Petcock - K1?

[jonbuoy]

Hi,

I have just bought a genuine Dunstall tank for my CB750, it didn't come with a petcock/fuel tap.  My petcock has a threaded fitting (F2), I have looked for adaptor plates but can't see any that will fit for the thread spacing I have - here is a drawing.  Could someone tell me if this is the same footprint as a K1 petcock?  Or any ideas what might fit or will I have to drill and helicoil (is this the best thing for fibreglass?)   

Cheers

John

[doug_id]

I think you need one of these petcocks along with the mounting screws and fiber washers.......

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=010&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=200063396142&rd=1,1

[Wis]

that's also the type of petcock from early 550's......for what it's worth.

[jonbuoy]

Thanks Guys,

It would be nice to get those dimensions off of one, I wonder how it does reserve with only one pipe in the tank?

[doug_id]

I think how it works is the middle pipe does not seal in its hole so when the gas drops below that level and you switch to reserve it just pulls from the gas that comes into the petcock around the tube and the middle hole in the tank.  I cut my tube shorter though as I thought it was pretty long.  + I never run out of gas on my bike....knock on wood.   

[doug_id]

BTW I have an extra petcock still in the wrapping(brand new) if you want to buy it for a discount over what you will find them selling for on e-bay.   I bought another one when I thought my original one was broken......good thing I like to buy high and sell low....!   

Doug

[Roach Carver]

BTW I have an extra petcock still in the wrapping(brand new) if you want to buy it for a discount over what you will find them selling for on e-bay. I bought another one when I thought my original one was broken......good thing I like to buy high and sell low....!

Doug

Doug, if jonbuoy doesnt want it, give me a shout. Thanks.

[jonbuoy]

Hey Doug,

Thanks for the offer - I appreciate it  -but being on the arse end of the world is a pain when it comes to shipping costs for single items, I'm going to put an order into Dave Silver for my engine parts so I will probably order from him if I get one.  At the moment I'm thinking of a plain pipe fitting with a jubilee clip and an inline gas tap.

Cheers

John

[chung]

Doug has the pic of the proper piece. It is common among aftermarket tanks. It takes an oval O-ring to seal it against the tank and a couple M6x1x30? screws with sealing washers. The whole rebuild for one is about $20-30 american.
The two outlets for fuel supply to the carbs are very important. One line will not supply a thirsty engine.

I hate it when I have to back peddel in third gear to let the motor catch up while my snooooootty opponent has his front wheel in the air with an arrogant grin on his ugly mug. Present company excluded, of course

[bryanj]

Dave Silver sells em new for £18 which is cheaper than Ebay!

[canttuckmyshirt]

This is great info!

So, will both a 500/550 and the 750 petcocks work?

You also said that we would need both outlets. Any one have a simple source for a replacement barbed outlet?

[jonbuoy]

I was thinking of braizing a pipe though a metal plate, I wasn't planning to use a barb unless I have to - they can be stubborn to get off again - I would be  worried about tearing it out of the fibreglass.  The two fuel outlets from the standard K fuel tap might be an issue as I have a single feed to my carbs.

Cheers

[bryanj]

Connet both outlets to a "T" piece and use the third leg to connect to your carbs, this is the only tap that will fit this tank to my knowledge--that is why the later Dunstall kits were just a think tank "cover" not a complete tank

[jonbuoy]

Thanks,

That might be a neater solution than having a seperate fuel tap and filter .