zenith carb problem (?)

My Commer's choke/strangler cable is unsheathed (unlike Panky's) and routed past that sender position causing an occasional earth to that sender wire causing the gauge to read hot when the engine wasn't.
So where is your sender then Doug?
 
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Ah! Strangler = choke ... small language barrier. Thanks.
It's like bono said: i still havent found what i'm looking for.
i cant see anything like a temp sender from the top and in order to work it really needs to be near the head, so remains a mystery at the moment. I'll have to trace the wire i guess.
 
Panky said:
Have a look at the air filter and check it isn't chocked up. Try a run without it to see what happens. If still no good remove the bend off the top of the carb. start the engine and warm it up, rev the engine then put the palm of your hand over the inlet. The suction caused should shift any bits of debris blocking the jets, be prepared though there is a lot of suction when you put your hand over the inlet.
While your there, with the engine off, look down the carb and push the accelerator, you should see a little squirt of fuel from the accelerator pump as you push the pedal.
Click to expand...
Panky : doing the 'palm over the air intake' trick has sorted it completely. Thanks loads ! He runs very nicely now
 
Hi All. Wasn't sure it was worth a thread of its own but still would like to know.

This weekend I’ll be pulling apart the carby and unfortunately haven’t got a refurb kit. When I pour fuel down the throat it starts and runs for a bit. But running from the fuel pump (have an electric one) it won’t start. If I take the fuel line off and put it into an empty bottle I can see the fuel coming through nice and strong. But nothing gets through to the carby/jets that I can see.

Any hints or tips before I pull it apart and hit every orafice with an air gun?

It's a Zenith 34 IV.
 
The old trick is to put the palm of your hand over the inlet and crank it, if it's a small blockage it usually gets pulled through. Also check any filters and the fuel pump for signs of debris that could point to the dreaded snakeskin.
 
Hi Panky,

By inlet you mean the throat of the carb? I currently have the fuel being drawn from a coke bottle as I haven't blown the fuel lines out yet. The fuel is good. It's the carb that isn't.
 
Sorry yes, pull the bend off the top and put the flat of your hand over it, works better if it's running but 'super choking' the carb on start up might work. Put a splash of fuel down the throat first, start it up and plonk your hand over, be careful though it doesn't half suck.
 
Hi Panky.

This message is good for one reach around. I owe you!

I pulled it apart and checked the floats anyway and all good. Hand over the throat looks to have cleared it. At least now I won't break the starter pushing it back in the shed on the starter alone.

Still leaking but it's progress. Good compression too. I'm hoping 125-130 on all cylinders is usable.
 
That's the float chamber overflow. Either the float valve is passing (possibly because the electric pump pressure is too high or crap under the seat) or the float has sunk.
I did here of someone using a Land Rover carb but it will be jetted wrongly so would run rich.
 
Thanks mate. I pulled it apart and put a new kit through it and when running it's kind of ok. Also fine when I pinch the line which means the EFP is probably over sized. I'll yank the top off and see if it's seating properly. I put it back together so there's every chance I left a part out of reassembly.
 
If running an electric fuel pump you'll need a pressure regulator usually...does it have one on? Pressure needs dropping to about 2 psi I'm guessing or will over fuel
 
If running an electric fuel pump you'll need a pressure regulator usually...does it have one on? Pressure needs dropping to about 2 psi I'm guessing or will over fuel
 
No! Good point. The fuel pump could very well be too high as it says 3-6psi on the side of it. That seems high.

I might piss it off and get some fittings for the mechanical one.
 
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