Further to t'other thread, progress is being made...
Engine now turns over quite spritely but won't fire. I have a spark, albeit not the strongest ever seen, but definitely a regular spark.
Disconnected the fuel at the carb and it's delivering plenty when turned over.
But no hint of firing. Even after 30-60 seconds cranking the plugs are bone dry - shouldn't they be showing evidence of petrol? If so, why wouldn't fuel be getting there?
In news: snipped-for-privacy@4ax.com, Tim Hobbs blithered:
Float chamber empty? needle valve/float stuck? Jets clouted up with detritous?
As I thought... I need to learn about how carbs work. Bugger....
Thanks :-)
On or around Sun, 17 Apr 2005 15:40:22 +0100, "GbH" enlightened us thusly:
one of they. either the petrol in the carb has evaporated leaving spooge, or the float valve stuck shut is my bet. Try a bit of percussive maintenance.
Yup ,, tap the handle of a screwdriver on the top of the float chamber lid a couple of times. Usually enough to free a sticking float.
Also try a squirt of fuel / wd40 directly down the inlet... if she splutters on the fuel provided at least you can eliminate everything else.
Lee D
Go basically pour some petrol into the carb and give it a slap?
Sounds within my skill set....
How old is the petrol mate?
-- Subaru WRX (The Bitch)
Series 3 Landrover 88" (Albert)
'"They called him Jimmy the gent"
You getting a spark on all the leads or just testing the one?
OK - tipped about half a pint of fuel down the carb. Much gurgling, so it went somewhere. Left it a few minutes (pudding was ready!) and then turned it over - lots of coughing and half-running, then the fuel ran out and it stopped again.
Hmm... Perhaps I didn't hit it hard enough?
You really need to meter the stuff into the carb as you are cranking if you are trying to prove that it is a fuel feed fault, with one person dripping it in you can adjust the mixture on the throttle.
Over do it and you need to dry the plugs off.
Once it's basically turning over under its own steam rapidly opening the throttle should pump fuel from the richening pump (depending on model and I stopped using a sIII 10 years ago) if there is fuel in the float chamber, if you can keep it alive like this then it points to blocked jets, if the throttle pump doesn't squirt fuel when its depressed it points to a blocked float valve (assuming the fuel pump on the side of the block gets fuel up to the carb.
AJH
I noticed the accelerator pump isn't working earlier, but forgot about it until you just mentioned it. I'm going to have to investigate further when daylight next coincides with free time!
On or around Sun, 17 Apr 2005 21:12:54 +0100, snipped-for-privacy@despammed.com enlightened us thusly:
stuck float valve gets my bet.
Right, had the carb off and taken the top off it. Float chamber had a bit of detritus in the bottom, but nothing spectacular. Cleaned it up, rinsed it all out with petrol.
Gasket looked all in one piece, inlet blows through with float down, doesn't blow with float up. All looks good.
Put it back together, with the float full of fuel. Refitted carb and turned engine over. Hey presto!
Bugger all. Nothing, nada. Still no fuel getting to plugs as far as I can see.
Just to recap - when I tip a glug of fuel in the carb the engine fires straight off and runs for 20 seconds nice and smooth (albeit with a lot of smoke as you'd expect). So the ignition side is OK (at least good enough for it to run).
There's a good splurge of fuel coming through from the pump.
When I flap the throttle linkage about should I see a squirt of fuel from the accelerator pump? I don't seem to be getting anything there.
Do I need to strip the carb down further? Has anyone had experience of the Zenith rebuild kits that are on the market?
On or around Fri, 22 Apr 2005 18:47:01 +0100, Tim Hobbs enlightened us thusly:
that's if you tip petrol down the inlet?
in that case, there's spooge blocking the bit twixt float chamber and main jet, I reckon. Was there petrol in the float chamber when you opened it?
The above could cause that too. Float chamber outlet tends to be at the bottom, and thus if it dries out, the spooge gravitates to the lowest point.
'fraid so, from the sound of it. If you have an airline, put a small nozzle on it and blow through an holes you can find.
When you floor the accelerator you should be able to see the stream of petrol in the carb intake.
AJH
Sounds reasonable I suppose. I do have an airline so I'll give it a go. I wonder if a squirt of WD40 with the little nozzly thing on it would shift it?
On the plus side, there are any number of carbs on e-bay. I'd be really chuffed to strip this and get it working, but it's more important to get the bloody thing out of the garage so I can empty my shed, so I can knock it down, so I can finish the patio, so I can move the garden furniture off the drive so I've got room to fix the Land Rover....
I stripped down my Zenith earlier this year and replaced all bits with Paddock's rebuild kit. Fairly straightforward job, even using HBOL for instructions. I'm a complete novice and took a couple of hours going really slowly and carefully.
Once you've cracked the whole carb in half you will be able to see any blockages in the channels that run through the blocks fairly easily.
Beware, some> >
Took it properly apart this afternoon and gave it a thorough seeing to with the degreaser (just bought a Clark parts washer, which makes life very easy).
It's obviously been apart before - some mangled heads and stuff, but no obvious blockages. I imagined I felt resistance when I blew one jet through, but wasn't sure. The taste of petrol may have been getting to me by then...
Put it all back together and refitted it. It was immediately obvious that the accelerator pump was getting something, as I could feel/hear it. Turned the key and away he goes!
It's all got to come off again - I'm going to get the Burlen rebuild kit for it and properly check the mating faces on the emulsion block for warp. It runs like a bag of cack, as the carb to inlet gasket is missing and the choke is similarly absent. But it runs....
Thanks guys for all your help. Austin - you were bloody right again....
On or around Sat, 23 Apr 2005 17:59:48 +0100, Tim Hobbs enlightened us thusly:
BTDTGTTS, and it's got oilstains on it.
Had no end of hassle with the 110, when I first had it - twin-choke weber on that, and the spooge in question had hid itself in a little hole at the bottom of the float chamber, where it was almost invisible.
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