Ran yesterday...Wont run today

[steveohara]

Try Terry Ives, Vince Hughes or Hansen Duncan for the carb parts. The original metering diaphragm in the DBC 14 carb had a metal plate attached to the fabric with adhesive. The later versions attached the plate with a rivet and that rivet makes the assembly thicker in the critical dimension between the fulcrum arm lever and the plate that covers the diaphragm. To offest the extra thickness in the rivet the later diaphragms were paired up with a gasket that doubled the thickness in the area where the diaphragm is sandwiched between the body of the carb and the center plate. You can use either type and the carb will work fine.
The .040" to .060" range of thickness for the circuit plate gasket stack does not include the steel plate.... just the gasket and fabric flapper valve.
Regards,
Steve O'Hara

[Eric Haynie]

I found a guy locally w/ a stash of parts. I found every thing but the extra gasket for the diaphram w/ the metal plate.
How thick is the extr gasket? Can I make one. Will one of the gaskets on the old diaphram work, (my old one can be seperated if I take out the staple)or will that be too thick? Should the arm be set flush or.010 below w/ the extra gasket?
Eric

[steveohara]

Eric,

The arm height can be fluch or a little below... it won't matter if you use the right diaphragm. Can you post pictures of the diaphragm you bought? If so, post a pic of the wet side, the dry side and a side view so I can see how thick it is. You can use the old diaphragm to make a gasket by simply peeling the thin flexible membrane off or if it won't peel off then just cut the center out so that all you have left is the gasket portion.
Regards,
Steve O'Hara

[Eric Haynie]

Steve,
My camera is not working.
The diaphram has 2 cardboard/Paper sides w the diaphram material sandwiched inbetween.
It has a metal plate on each side of the diaphram material w/ a rivet in the middle. one of the plates has a series of holes in a circle. my old diaphram is the same. I can take it into 2 parts. 1 cardboard......1 cardboard w diaphrm material attached. I put my carb together w/ the one cardboard/paper half then the new diaphram,then the plate.etc.etc. I have presssure tested it and it holds at 5 lbs no problem....But it never popped off. My gauge goes to 20 lbs and it did not pop off. It will hold at 20lbs .
Got some new plugs.someone had put a campion j2j in it. I asked on the board and Jeff said go w a champ L78. I found a champ L78c (the c is for copper) will that work? also got some NGK B7HS what do you think of these? What should they be gapped at?
Thanks
Eric

[Eric Haynie]

I installed a gauge that would read higher on the pop off gauge....it pops off at 29psi and stops falling at 20psi.
eric

[steveohara]

Sounds like you have the right diaphragm and the arm height is set properly. Now you just need to take the fulcrum arm out and squish the spring down as much as you can to lower the pop off pressure a bit. Try to get it down so it will "spit" at around 20pounds. Spray a little WD40 down in the area of the inlet needle and you'll get better read on the test.
Steve O'Hara

[Eric Haynie]

Thanks everyone....It is now running great, Thanks Steve for all the carb info.
Eric

[steveohara]

Let's wait and see if it runs tomorrow!

[Eric Haynie]

still running!!!
Thanks Steve
Eric