these *&^%ing carbs again

C

cooper1203

Member
Ok I have put these bloody carbs on again after a complete rebuild with every single possible thing that could be replaced replaced. set the jets where they r supposed to be and started the engine to warm it up. I now have petrol pouring out the overflow pipe on the passenger side the engine runs like a bag of nails then picks up then back to a bag of nails.

what the hell is wrong with the bloody things now???
coop
 
Petrol out the overflow sounds like a sticky float or needle to me.
Give it a carefully calibrated tap with a buggering stick handle. :mrgreen:
 
hi thanks for the replies the floats were changed along with the needle valves and seats. I set the float as per the book carefully making sure that the 1mm was 1mm not in the great scope of +- 0.5mm.

I took the offending article off again and by blowing through the inlet I made sure the valve was working. I also double checked my measurements and all were ok. I put the carb back on and it wasn't leaking let it get up to temp and then switched off to set the carbs as per the book. when I started it up it was idling too slow so I turned the screws in a little on both sides then gave it a rev to clear it through as the book says and low and behold the fuel poured out the overflow.

I gave the side of the carb a clump with a screwdriver and it stopped. went back to tuning it gave it a rev and all ok. made a cuppa and the was a small lake on the floor. tap the side of the carb its fine soon as I rev it the fuel pours out.

I am rapidly going off su carbs they seem to be utter rubbish. I had a mk2 scirocco b4 this it had stood for 15 years I had the carb checked once took all of 10 mins to get it right did about 5000 miles over 2 years if that it. when I did drive it I would take it a max of 30 mins away to a show park up then drive home. in the 2 years I had it never had to touch the carb or anything. these bloody su's need a rebuild after 10 miles.
coop
 
I had a problem with HIF6, I set them as per the manual but got some over flow.

if you definatley have the correct needle valves (there is rogue listings) then a tip I got from youtube was to hold the body side on when setting the float instead of upside down.

That worked for me.

Colin
 
I have the old float, valve and seat tomorrow ill put them back in and see if that makes any difference.

When I set the float I took great pains to get them bang on 1mm so they would be the same. how critical is it. does it matter if they are slightly different? I ask because I have no idea what the original float is set to and reluctant to change it as I know it didn't leak b4.
coop
 
im just getting thoroughly fed up with these things. I have spent close to 1000 pounds now on rebuild kits and garage fees trying to get these bloody carbs right and still they wont play ball. the car has been on the road for a year and I don't think I have been out for an enjoyable drive once with out it messing around or breaking down. its getting bloody stupid. by now I could of bought a holly carb and manifold and been off down the road with no issues what so ever.
 
Some floats can fail very quickly. I replaced the floats in my carbs and within a week or two one carb was overflowing, spilling petrol all over the road at idle. Removed and checked float, found to be full of petrol, so fitted another float. No problems since, and that was 8 years ago.

Ron.
 
Most people on here are running SU carbs just fine... I think there must be something fundamental that is getting missed here, or is it just me?

Rich
 
rockdemon said:
Most people on here are running SU carbs just fine...
Click to expand...

+1

And not only here...
Surely the carbs themselves are not to blame.
If you cannot succeed with fault finding, instead of stressing yourself and blaming the car, it is time to admit defeat and trust someone who knows his way around them.
 
hi, im in kent. however I changed the valve and seat and the overflow stopped running like a tap. I also went to my friends today and we made sure the balance was 100% on and set all the linkages as per the book. he had a tacho thing that u stick a reflective plate on the crank pulley so we set the idle with that. then used a gunson smoke tester and the co was around 6-6.5 tried using the lifting pins and got it as near as we could to being right. next stage is take it to a mot place and waft some beer tokens under their nose and get them to put it on their sniffer to see what the hydrocarbons are doing.

I did take it for a test run after and was quite brutal with the throttle and it seems 1000% better than it was.
 
hopefully you're getting somewhere at last then :)

Maybe someone on here can help if all else fails?

Rich
 
did you put the original needle valves back in?

I have noticed ones with metal tips and ones with viton tips. i prefert the later myself.

Colin
 
I put the old needle valve that was in the passenger carb back in along with its seat. When I took them apart the passenger side valve had the rubber tip the drivers side had the spring loaded type. Both new ones were rubber tipped.

I did discover that u were only supposed to lift the lift pins 1/32" after the slack has been taken up so that is why I probably couldn't get the carbs rich enough as I was pushing them up as far as I could.

My problem is I know nothing about carbs and couldn't tell u what fault would cause what symptoms or visa versa but it is all a learning curve and one im sure I will master one day lol
coop
 
Yes there are a few types and if you mix the needle up with the wrong seat they stick...some are viton rubber others are metal, the metal ones have a spring loaded pin at the other end (from memory) which makes setting them a little tricky. I remove the bell and piston, pull the choke full on so you can see down the jet and check to see the fuel height, and if it keeps coming up to the top....the height is wrong. But it sounds like the needle is sticking as the overflow stops when you tap the bowl.The lesson is once you have it set don't go playing with it! You'll stuff it up again....It'll be fine forever once set unless you get dirt down the line in which case just clean it, don't try resetting it.
 
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