mike james

mike james

New Member
Hi All, I have searched relevant forum posts to no avail – wonder if you can help.
I have had a Weber 34 ICH carburetter fitted to my 1971 2.25 petrol S3 for the past 6 years with minimal problems until a blocked idle jet last month, I took the carb off the manifold, stripped it and compressed air cleaned all orifices, galleries, jets, checked float height & needle valve condition plus renewed the in-line petrol filter.
Since that strip down & reassembly all is well with the running and performance BUT with the engine warm if I park up and switch off for 30 mins on restarting the engine it runs way over rich with black smoke for a couple of seconds, then clears and runs normally. Its just as if the carb dribbles into the manifold from the float chamber when warm (this does not happen starting from cold) My very first thought was not carb connected but valve guide seal wear, so I fitted new ones but it made no difference and problem persists.
I would welcome any ideas ?


PS. Perhaps I should have put this in Common Faults & Questions Forum. Moderator please move if you wish. Mike
 
try dropping yer float levels a bit....obvious that when warm yer gas in the bowl is expanding and running out thru the venturi
 
other thing ya can check is yer needle and seat in thu carb....they sometimes seem ok till ya open tha carb, then the rubber coating on the needle dries out completely and cracks.
 
mike james said:
My very first thought was not carb connected but valve guide seal wear, so I fitted new ones but it made no difference and problem persists.
Click to expand...

stuffed valve stem seals normally would give ya loads o white smoke on startup
 
Bushtoy, Brilliant idea, I will try it tomorrow morning just as soon as THE BOSS says I can go outside and play !
Its one of those problems that gives one the nagging suspicion its self imposed and it really is bugging me, will try your suggestion and report back.
Many thanks I owe you a beer ! Mike
 
ey up, the language barrier has dropped in, what the **** sort of a half cocked answer is that kaffer shagger
 
where is the English language from? England! so who what is the correct way of using it? the English way! there is no such thing as us english of sa english it is a microshaft construct
 
petrol is short for 'petroleum', which describes loosely, the products from a petroleum refinery. on of those products is 'gasoline' which u poms call 'petrol'. go check it out in yer wonderful oxford dictionary
 
This is a common problem with Weber type carbs.

Usually it is due to carb flooding because the fuel lift pump remains PRESSURED after the engine stops ('cos it is spring-loaded) and so the lift pump holds fuel under pressure on the float needle valve. Like the man said, these are dodgy leaky items, and so the fuel in the pump will seep past the needle valve, over-fill the float chamber, and pour out through the jets into the manifold. Flooded engine five minutes later.

CharlesY
 
Bushtoy,
Make that a couple of Castles at least,Bloemfontein nearly floated away on the stuff earlier this year when I was there with No 1 son ! Great company in a glorious country and a Camel discovery to ride around in (owned by a friend)
Happy memories. Mike
 
Charles Y, Many thanks I think your thoughts have hit the nail on the head, logical after all, I will try lowering the float height to compensate for the pressurising of the float feed and see if this cures the problem. Thanks to all problem solvers. Will report results. Dinner gong has gone and my G&T glass is empty. Mike
 
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