Carb

Technical questions and Maintenance advice post in here please
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wvs
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Carb

Post by wvs »

What symptoms would my carb (948cc) display if it were in need of a refurb.
Engine runs ok, have given it a colour tune etc. The carb has probobly never been touched since the 1960's so are there other factors that determine the health of the unit.
I am getting fumes in the van when windows are open and therefore wonder if the carb is allowing too much fuel through the engine despite the above.
Thanks
AW
SteveClem
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Re: Carb

Post by SteveClem »

Fumes are more likely due to decay in the fuel lines I would think.
Nikki&Austin
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Re: Carb

Post by Nikki&Austin »

....and pin holes in the fuel tank, rotten filler hose ?
wvs
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Re: Carb

Post by wvs »

Fuel lines are new, also rubber connections, the fumes are not petrol but from the combustion side ie exhaust hence my query re health of the carburetor.
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David Swain
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Re: Carb

Post by David Swain »

Check the length of the exhaust pipe, as if too short on a van, fumes can be drawn in through the back.
David Swain. Member No. A1743
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Hoppend
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Re: Carb

Post by Hoppend »

i know that from expirience that a leak on the connections to the fuel pump could also cause the smell.

What is the fuel consumption like?
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David Swain
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Re: Carb

Post by David Swain »

If engine is running fine, then I wouldn't be too worried about the carb, may be better to leave it alone.
You could try spraying something like wd40 or easy start, (not sure what would be best as I have not tried it) around the carb joints and spindle etc. While the engine is running, and see if there is any change in running, if so you may have a gap somewhere drawing in air, I would have thought you would get associated running problems though if this were the case. My car had a very dodgy join in the fuel line right next to the clutch rod, and also a pinch in the fuel line possibly from an engine removal, I have now replaced the fuel line with modern from a few inches away from fuel tank, to where the metal line leaves the engine bay (as all the line in the bay was still good). Place some cardboard under the car and run it for a little while to see if you get any drips anywhere, they show up really well on the cardboard.
David Swain. Member No. A1743
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David Swain
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Re: Carb

Post by David Swain »

Had Rev running again today, as I was trying to clear the garage out, and just for fun tried spraying easy start around the carb, and guess what engine ran better....... :?
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A30 van 55 'R.G. Swain', A35 4 Door 59 'Little Gem', A35 2 Door 59 'The Rev' '+1'
wvs
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Re: Carb

Post by wvs »

Thanks for the suggestions I will try them out.
AW
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Neil Evans
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Re: Carb

Post by Neil Evans »

David Swain wrote:Check the length of the exhaust pipe, as if too short on a van, fumes can be drawn in through the back.
:iagree: Common fault on vans and countrymen... :thumbs:
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Ann and Roger
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Re: Carb

Post by Ann and Roger »

A couple of points to consider. Are the fumes coming from the crankcase breather these could easily find their way into the cabin particularly in a van. Assuming the rear door seals are in reasonable condition then exhaust fumes in the car are less likely particularly if you are moving on. Spraying cold start on hot areas is not a good idea, it is highly flammable, oil is a safer bet. I had trouble to get my car to run properly setting the slow running jet seem unpredictable, fiddling with the choke seemed to help the running a bit. Eventually tied down the problem to an air leak by the heat insulation joint at the bottom of the carb. The bottom of the carb had a distinct bow 15thou, I noticed it by evidence of a dark band on the flange, careful use of a sharp flat file then lapping the flange on a flat plate and 320 grade wet and dry did the trick.
Best of luck, if you have fuel dripping on the floor, TIME TO LEAVE.
wvs
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Re: Carb

Post by wvs »

Thanks for the comments, no fuel on floor, like I said earlier I am getting exhaust fumes not petrol. Will check the breather, also the exhaust downpipe to manifold joint whilst I am at it.
AW
wvs
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Re: Carb

Post by wvs »

What size replacement needle would the SU require, the engine is a 948cc. Don't want to refer to the existing one in case it is wrong. I have been asked to supply the correct reference for it.
AW
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Nelly
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Re: Carb

Post by Nelly »

wvs wrote:What size replacement needle would the SU require, the engine is a 948cc. Don't want to refer to the existing one in case it is wrong. I have been asked to supply the correct reference for it.
AW
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Neil Evans
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Re: Carb

Post by Neil Evans »

wvs wrote:Thanks for the comments, no fuel on floor, like I said earlier I am getting exhaust fumes not petrol. Will check the breather, also the exhaust downpipe to manifold joint whilst I am at it.
AW
Check also the grommets and blanking plugs in the bulkhead and not forgetting the throttle linkage bellows and gear lever gaiter... :thumbs:
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