Zenith experts

[andyfrost]

Gents , having a problem with a zenith 24T2 on a JAP 4/3.
I have so far fitted…
New float
New needle and seat assembly
New variable main jet
Turn petrol on and it will stand for ages without leaking , as soon as I pull it over , petrol literally floods out , anyone familiar with these will realise it’s not that easy to tell exactly where it’s coming from , due to the tight space.
Any thoughts would be much appreciated.

Andy.

[stuart]

Is it fuel coming out where the choke butterfly is located ?.Maybe you are giving it too much choke and its just the surplus fuel thats dripping out ?.On my Howard 400 it dont need much choke at all.Have you tried opening the tap on the inlet manifold to “lean” the mixture to see if the engine will at least start and run ?.Is the gasket between the upper and lower bodies ok ?
Im sure my carb has a fixed main jet Andy,not an adjustable one ?.How many turns out have you set it at ?.Have you tried screwing the jet it and see if it still floods ?.Its been a couple of years since i started mine up but i know it only needed half a pull up on the handle on the compression stroke and it would start.

[vhgmcbuddy]

Just a thought but could the inlet valve be not seating properly thus causing a back pressure through the carb when the engine is turned over.

[andyfrost]

Stuart , it’s coming from around the carb itself , not from the choke.Mine does not have the “tap” in the manifold , I’ve adjusted the main jet in to no avail , and the gasket is A1.
Iam truly baffled over this one.

Sten , the valves have been refaced and seats re-cut.

Thanks again chaps.

Andy.

[stuart]

I would think then that either one or both of the carb bodies are distorted and its leaking because the gasket cannot make a seal.Try a straight edge on the carb bodies and see if you can see daylight anywhere between them.If you can then im sure thats where your trouble lies.
What machine is your engine fitted to Andy as i see it was a JAP 4/3 model and i just thought it may be a Howard 400 rotavator but i guess this engine was fitted on numerous other makes of machine as well.

[andyfrost]

Stuart , I’m certain it’s not distorted , besides which the fuel level would not be that high anyway, plus it’s leaking from round the bottom.
It’s on a Coleby Cultivator.

Andy.

[will-haggle]

Here’s a bit of JAP & Zenith information I got from semidiesel. This information is now held by http://www.internalfire.com/…..

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[andyfrost]

Thanks for that Alan , always handy for reference.

Andy.

[vhgmcbuddy]

hi andy, any update with your carb??

[andyfrost]

Kev , not at the moment , haven’t had time lately………been too busy cropping the allotments , and working.
Will have another go as soon as time permits.

Andy.

[vhgmcbuddy]

Strange that its not sorted yet.looks very complex,it reminds me of one which was fitted to a Hillman Husky side valve engine.is it possible andy that the float is to high in carb and its causing it to flood.

[Author]

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