26 Super 6 carburetor problem

Unknown

Hi all,



It's time to get my 26 started again for the first time in 8+ years. I've re-installed the exhaust manifold, replaced the exhaust, installed a custom made gas tank, re-built the vacuum canister, re-installed the intake manifold, added the fluids, and now's the time.



Here's the problem. I'm getting gas to the carb (the bowl is full), getting spark all the way to the plugs, but no gas to the cylinders (and, the butterfly valve on the carb is dry). I took the carb apart, but it's way too different than I am used to, and too dark to deal with tonight. Even still, I don't know how this thing is supposed to work, so I don't know what to look for. I figure there is a needle valve (or other small orifice) that's blocked, but I could use some help in the operation of this.



Way back when, my grandfather told me that to keep gas from running out of the carb when it wasn't running, he propped a spacer in the opening on the back of the carb to prop something up. I noticed that it seems to be a weight, on a spring, and I suspect that it somehow vaporizes the gas to be sucked into the cylinders when the butterfly opens. Is this close? What position should it be in, when, and how? I'm so confused



I know there is spark and no gas because the new plugs (oh yeah, I forgot to mention them) are dry. I verified the spark at the plug, and blew a little ether into the cylinders. I got a quick pop from the ether, but that's where it stopped. I figure it's coming back out tomorrow, so any help would be appreciated.



Thanks.

Jon B

Bide your time....Geoff Clark will soon be along to make everything clear...

Geoff

How did you know Jon??? Okay, the Stewart carb works on a tapered needle in the orifice, which rises up and down according to the throttle opening. Air passing through the intake lifts the top bell, which is attached to a dashpot in the carburettor body. First of all, if you have had the engine apart, I suggest you put your hand over the intake as the engine is being wound over. You should feel a good strong suction. If not there is a leak somewhere in the intake manifold or the carb gasket. There is no choke, only a mixture control which lowers the needle. If you have plenty of suction, then you should have fuel running back out of the carb after holding your hand over the opening. It is unlikely that the nozzle is blocked. You should be able to lift the bell up with your finger through the intake, and it should fall back down slowly, as it has to displace the fuel in the dashpot. Contact me at geoffclark@xtra.co.nz and I can scan the relevant carburettor section of the workshop manual and email it to you. These are a virtually foolproof and indestructible carburettor.

Geoff.

Unknown

Thanks, Geoff. That makes sense. I actually had most of it figured out correctly, and you answered the rest of the questions that put it all together. You are correct about the orifice in the middle of the bell, it is open, I checked it last night.



I'm suspecting a leak somewhere in the intake or carb gasket because the rest works as you described. They are both new, but......you never know. I'll try putting my hand over the intake to see if there is any suction later today.



A question, though. If there is suction, does that pull the bell up? And if so, how does the fuel get through the bell into the carburetor body and into the intake if the bell falling pushes fuel back into the dashpot?



I sent an email. I would appreciate any relevant information you could send.

Geoff

It doesn't push fuel back into the dashpot. The bottom section is just a damper to stop fluctuation of the assembly. The middle section is hollow, and the fuel is drawn up around the tapered needle.

Geoff.

Unknown

I had a similar experience with my 31 Hudson 8. Not the same carb but it does have the same vacuum fuel tank. Check to see that you are in fact getting gas at the carb. You can see this by loosening the fitting at the carb. Does gas run freely from the tank? Well that was my problem. I verified it by shooting some air into the fuel line and then the blockage was cleared and fuel ran freely. Then I cleaned the vacuum tank out and haven't had any further problems.



Good luck

Steve

Unknown

Well, it looks like it's on to the next problem.



I verified gas at the carb already. I knew it was there because I filled the vacuum canister directly, and had fuel in the dashpot.



This morning, something that Geoff mentioned got me to thinking. Since the rod was already disconnected from the mixture control, I decided to remove the spring as well and see if I couldn't get something to work. When I moved it all the way up (or, the same as pulling the control all the way out), it fired. After fiddling with the spark advance a little bit, it actually started to run. Yeah!!



So, playing with the mixture fixed the problem. I presume that the proper adjustment is to get it running as best it will, then attach the control arm and dashboard control so that you have it in the right place, right?



Anyway, it ran until the vacuum tank ran out of gas. Looks like I either have a blocked fuel line or a vacuum tank not working properly. Looks like that's the next place to start working.



Thanks for the suggestions. On to the next problem.

[Deleted User]

Hi,



Anyone got a rebuildable 308 and standard trans for sale (or donate to Niels "Katrina" Pedersen)? Preferably close to So. Cal. Thanks, Niels