Stromberg Holden Carburettor Leaks

[Lionelgee]

Hello All,

I was just working on a Series 2A which had a Holden 202 motor fitted that was from a HQ to the shortie Land Rover. One of the areas of interest was its fuel supply. In particular I noticed how fuel literally trickles out from the bottom of the float chamber. It then drops onto the intake manifold and down on to the hot exhaust manifold.

I removed that carburettor and installed one that I had bought second-hand. This newly installed carburettor leaked too from the same place.

A number of years prior to today's experience I had another Holden Stromberg carburettor and it leaked from the same place too.

What part - gasket or seal is giving way to allow the loss of fuel?

I intend to thoroughly clean and rebuild the carburettor - it would be just good to know.

Kind regards
Lionel

[ian4002000]

you will need to post a photo of a carby upside down to refresh my memory. There is a plug for the main jet that should have a copper ring gasket on it.
These usually dont leak but if the copper is missing that could be the problem.

Ian
Bittern

[akelly]

my money is on the main jet cover leaking. Often people crush the copper washer when putting it back in. Could also just be the float level is too high and fuel is running out over the accelerator pump linkage.

[1950landy]

The copper washers on the two plugs if you are not careful can get distorted. It could also be coming out the throttle shaft if the carby is flooding.

[bemm52]

Had the same problem when we cranked up my 3.3 the other day
Fairly hard to see where the leak is actually coming from and at first we suspected the two screws with copper washers at bottom as mentioned above
Tightened screws and problem was still there, lifted top of carbie and float chamber was full and overflowing down lever thingy at the back
Undid fuel line boss coming into float chamber and found some crud stopping rubber capped needle from seating....actuated by float arm a bit like a ball cock valve in a tank
Cleaned and reassembled problem gone
initially we were convinced it was the two screws underneath so...I’ve probably over tightened them[bigwhistle]

Cheers Paul

[Homestar]

Yeah, had this issue myself on more than one occasion - float level or needle and seat is where I’d be looking.

[Tins]

Kits for these are readably available. I'm with Gav, needle and seat, but that will cause rich running to say the least. The old ones had brass to brass needle and seats. The newer ones had some sort of plasticky needle. It was supposed to seal better. Sure.

Bung a kit in it, set the float level ( fun ), and it'll be fine. I don't like Strombergs, but it's hard to find a simpler single choke carb. Well, SUs apart. But SUs were special.

[Lionelgee]

Hello All,

Thank you for the replies. I will have a closer look tomorrow at the replacement carburettor and try to establish exactly where it is leaking from. Both their previous histories and last time the carburettors were regularly used is unknown.

Both carburettors had to be given petrol down the throat to initially start the motor. However, as soon as the fuel entered the top it was exiting the bottom.

The initial fuel delivery was sporadic and weak. I subsequently removed the outlet pipe and cleaned and flushed the gauze. Then installed all new fuel line. Fitted a new mechanical fuel pump, Fitted a new inline fuel filter before the fuel pump.

The car starts with the newly fitted carburettor with the first press of the starter button. The engine can handle increased revs and then goes back to idle. The disconcerting thing is the trickle of fuel out from the bottom of the float chamber onto the manifolds.

I am starting to lean towards the suggestion of of the float level and fuel rising up and out over the accelerator pump. The area around the screws does not hold any drips.

I will be ordering an overhaul kit once I have light to read the identification numbers by.

Kind regards
Lionel

[Homestar]

Kits for these are universal and contain all the parts for most models - you’ll find you’re left with a pile of parts from the kit once your done. Last time I did one the kit was $14 - not sure what they run to these days, it’s been about 15 years since I did one.

Let us know how you get on. 👍

[Tins]

Kits for these are universal and contain all the parts for most models - you’ll find you’re left with a pile of parts from the kit once your done. Last time I did one the kit was $14 - not sure what they run to these days, it’s been about 15 years since I did one.

Let us know how you get on. 👍

You got a top gasket and a needle and seat left?? Bloody things are $40 plus these days on stealbay. My 109 has a stromberg which has a spud for the LPG so I can't change it. Needs a kit. It never ends. I'd like to bring it to Wombat, if The Chairman allows it.

[1950landy]

Kits for these are universal and contain all the parts for most models - you’ll find you’re left with a pile of parts from the kit once your done. Last time I did one the kit was $14 - not sure what they run to these days, it’s been about 15 years since I did one.

Let us know how you get on. 👍

I bought a kit from Repco last year , almost had a hart attack when he told me the price. It was more than $30 & am thinking about $60 for the kit. I almost didn't buy it but I was doing a favour for a friend who has developed Dementia & was trying to get his S2 running so the family could sell it.

[mick88]

Lionel if your putting a kit through the carby it is also advisable to hone the top cover on a piece emery or wet n dry paper sitting on a piece of glass. The tops are prone to warping and allowing air to be suck in, you wont get it running perfect if the top is warped. Honing them is easy and takes only a few minutes to do.

Secondly you can run an engine at idle with top removed from a Stromy to check the fuel level and make sure the needle and seat are not leaking, you just need a small tab of cardboard to place over the air venturi to make it run even. But don't rev the ring out of the engine whilst doing this or you might get fuel spillage onto the manifold.

With a kit through them and in good tune, which is easy to do, they are a trouble free carby.

Cheers, Mick.

[Lionelgee]

Hello All,

In the cool light of morning the engine started first press of the starter button. I stopped the motor once the petrol started flowing out of the bottom of the carburettor. After taking the top off I found the float chamber full and overflowing with the float up as high as possible. As A Kelly and others suggested the fuel is leaking over the accelerator pump linkage.

I put everything back together and waited about ten minutes. The engine started again after the first press of the starter button. If the engine stalls and the button is pressed immediately it will not start. Wait until sufficient fuel has leaked out of the carburettor and the engine starts first push of the button. So it is the float levels and related fuel level adjustments.

When I first started with Land Rovers with Holden motors I tried to head off a problem with carburettors by getting a mechanic to fully re-kit the carburettor that came fitted on the vehicle. The first thing the carburettor did when it was returned to the motor was to leak fuel out the bottom.

Later when I learnt how to read the codes I identified that it was a 149 carburettor fitted to the 202 motor.

Looks like a rebuild kit is in order.

Kind regards
Lionel

[bemm52]

Try cleaning the needle and seat you have the same problem I had with float chamber overflowing
I didn’t change float level as all was good after crud was removed ,if you Carefully remove brass union that fuel pipe nipple screws into from carbie body inside is a three cornered needle pushed in and out by a tab on the float.
Looks a bit like a button from float side when in carbie
took about three seconds to blow out union on my bench and all was good......could save you the cost of a kit, and resetting float level

Cheers Paul

[akelly]

Try bending the float tab down a smidgen, that may solve the issue. At lease enough that fuel isn't dripping onto the exhaust while you get a rebuild kit.

[bemm52]

Guess what...... started my engine to get it up to running temperature and the carbie started overflowing again[bigsad]
So I pulled top off and the float chamber and it was brimming with fuel, pulled the fuel pipe union off and another piece dirt stopping needle seating, I replaced all the fuel pipe before the filter and used an old short piece after the filter when I replumbed the fuel lines. This must be the cause of my problem

Cheers Paul