Clementine's Garage
Clementine the Cat
 
Image of flower
Yellow R4
 
home my cars restoration tech tips guides forum
Réparateur d'automobiles

Carb problems

N

nickh

Enthusiast
Messages
8
On my R4 I get frequent non starts caused it seems by the float chamber flooding. It appears that the inlet valve is not always closing the flow when the float has risen to the top. You can see petrol gushing out the carb.

As long as the car is moving it's okay, and its okay if the car has been left long enough for the petrol to evaporate, but a restart in under 30 mins doesnt happen and I have to take off the top of the carb and basically slop out the petrol and give the brass inlet valve a stern talking to!

Now the brass valve is sealed. You cant take it apart. Such a simple device but somehow it must be sticking now and then for some reason. Can I get a new one?

Its a tricky carb to judge type as the car is 1989 ex French coppers car and so is a bit non standard.I assume its a zenith still tho and I have collected various numbers off the body

Can anyone advise? is a new/refurn carb a better bet? French MOT is now draconian about emissions and over rich mixture is a fail and older carbs to tend to run rich
 
I had this problem recently and there was a long exchange of Posts in the middle of 2010 under the Thread "Carburettor Overheating". It might be a defective needle valve, but in my case it was definitely the carb absorbing heat from the exhaust manifold after the car had stopped, and the petrol boiling off.
There is an improvised fix mentioned on the Thread. I solved my problem by fabricating an improvised heat shield out of old Meccano and painting it white. Opening the bonnet immediately after a run might also help, to allow the excess heat to escape.
 
benchseat said:
I had this problem recently and there was a long exchange of Posts in the middle of 2010 under the Thread "Carburettor Overheating". It might be a defective needle valve, but in my case it was definitely the carb absorbing heat from the exhaust manifold after the car had stopped, and the petrol boiling off.
There is an improvised fix mentioned on the Thread. I solved my problem by fabricating an improvised heat shield out of old Meccano and painting it white. Opening the bonnet immediately after a run might also help, to allow the excess heat to escape.
Click to expand...

Hmm well judging from the petrol gushing out the carb it seems to be a sticky valve, there's plenty of petrol in the float chamber! So unless the heat is causing the float valve to jam I don't think its heat related.
 
It is possible that you have some debris in the needle valve. Do you have an in-line filter between the pump and the carb? What carb do you have fitted?
 
I wouldnt be surprised, but the brass valve cannot be dismantled can it? No, no filter, might be an idea. Bit unsure on the carb, we've been through a few and this one has lost a lot of its markings but it is a zenith and I can make out 28 1F on top section V05078 B (or 13 or 8 or 5 instead of B) and 85 04 17 on carb body.
 
Okay - it's the standard 28IF. Take the valve out and blow it through with an air line. Remove the fuel inlet from the top of the carb and you should see a gauze filter. Remove this - and then blow through the top with an air line. Clean the gauze filter, re-fit all parts. Use your finger to lightly hold the valve shut whilst sucking and blowing through the fuel inlet. If there is any leakage then you will soon find out. Add an in-line filter between the pump and the carb and then put everything back and see if the problem is cured. If not then you will need to get another needle valve. You may still be able to buy the overhaul kit from the Carburettor Exchange, Leighton Buzzard.

http://www.carbex.demon.co.uk/

Phone them rather than use email
 
yeh steve all sounds like good advice, not sure where I can find an airline in deepest france, the petrol stations keep em under lock and key and u have to ask! Ive always found the valve works fine under suck and blow tests, it just seems to be erratic really. Ill check on an overhaul kit.
 
Nick
You should be able to get a new needle valve pretty cheaply from the Melun Retro Passion website
 
nickh! make yourself a make-shift airline by filling the spare-wheel by as much air as you dare...you can buy a connector-or make one that fits the tyre-valve ,a lenght of plastic-hose and a cheap blow-gun and you're in business -R.
 
ah thanks Andy, ca y est non?

POCHETTE CARBURATEUR COMPLETE ZENITH 28 IF (JTS CUVE+JT BASE+POINTEAU)
and only Euro17, has the valve and gaskets
 
You must log in or register to reply here.
Community platform by XenForo® © 2010-2024 XenForo Ltd.
Back
Top