CARB ADJUSTMENT ??

[Deleted]

Hi everyone, Mike here again in Norfolk.
My son and I have made good progress with the 2 cars we bought.
His is now spot on and running well. Mine is proving more troublesome and I need advice. Just to explain - It had been standing since 93 !!
I went through the ignition side and replaced the points, leads etc., and reset the dwell and timing spot on. I removed the carbs and thoroughly cleaned them and fitted new jets and needles, new float chamber valves etc., and made sure they were ok before fitting them back on the car.
I was delighted when it instantly fired up and ran. I let it warm up and found their were no heating issues and it ticks over very well.
However !!! Try as I might I can't balance the carbs. Looking from the front of the car I'm getting a strong hiss in the intake of the right one and virtual silence from the left one. If I lift the pin on the right one it increases speed slightly, but on the left one nothing happens. ?
Inreasing or decreasing the mixture doesn't seem to make any difference. There was black soot coming from the exhaust, and the plugs were sooted up so weakened the mixture and now find that the car has no power when I drive it. It doesn't want to go ?? It doesn't rev out freely and seems weak. I checked the float chambers and found the left one was half full. I put it back and checked the return pipe to the tank whilst the engine was running a found a flow of fuel going through it ??
Why ? I don't understand that ? It seems to be stopping the float chamber from filling up ? I gradually stopped the air flow to the intake on the right one and it stalled when nearly blocked. I did the same on the left one and the engine kept running with the intake totally blocked off ??
I then blocked the intake from the rocker box and it still kept running
Does this mean it's taking it's air intake from the right ??
I'm taking a break at the moment because I don't know what to do next ? It may be that I've missed the obvious ??
Any one got any ideas I can try please ?
Many thanks, Mike

[Phil Nottingham]

To balance the carbs properly - follow the handbook - you must disconnect/loosen the linkage between the two. Also set the mixture nuts the same on both to start with 1.5 turns down from fully up is a good start.

The spill return is working correctly - if the chamber is not filling up the needle or vent is sticking/blocked

[Deleted]

Thanks Phil, I'll start from scratch again tomorrow morning following your advice and hopefully I'll crack it !
(I did in fact put new needle valves in the float chambers.)
Mike

[Deleted]

Hi Phil,
I went back to the carbs today and began to reset them but I could smell petrol.
I found that it was coming from the pump. It was soaked in petrol and was leaking from the gasket.
I removed it and found that the screws were all loose around the diaghram. I redid them all and put it back on.
My theory now is that the carbs were being starved of petrol intermittantly. However, having disconnected the feed pipe at the tank, as it said to do in the manual, I can't get any petrol through at all, and flattened the battery trying to do so. !! Exasperating !!
I reckon it's an air lock, but how do you get rid of it ??
Your advice would be appreciated yet again.
regards,
Mike

[Phil Nottingham]

The mechanical petrol pump should pull out an airlock - if it does not, its past it. The long term solutuion is to fit an electric version (use SEARCH for more details) or recondition it - the linkage and/or cam will be still be worn, or fit a substitute - the club did one - very good too.

As a stop gap and to eliminate a blockage through rust/sediment just attach a tube on the engine end of the supply pipe and blow through. it should be quite easy and you should hear bubbles in the tank

You have renewed the in-line filter at the front?

[Deleted]

You were right PHIL - Fuel pump is kaput !!
regards,
Mike