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loose carb nipple
Posted: 11 Apr 2010, 12:20
by baldiebird
My van has recently come back from the garage to try and sort out backfiring problem. (suspected fuel starvation). Unfortunately they could find nothing wrong
I have decided to have a look myself. I noticed the fuel pipe coming off the left hand carb seemed to move about, so I tightened the clip, however still appeared to be loose.

I then pulled on the pipe and the nipple came out of the carb
Could this be the cause of all my problems. Can I somehow glue the nipple back into the carb or will this require specialist repair.
Hope someone can help as this is driving me up the wall. I have only had the van since December and it is rapidly starting to p me off.
Re: loose carb nipple
Posted: 11 Apr 2010, 13:01
by Mushr00m
Carb nipple?
I'm pretty sure you mean the fuel inlet tube(small brass pipe).
They are as far as I'm aware a shrink fit into a carb'. You should
be able to refit this but you'll have to expand the tube where it
fits into the carb by heating it & getting a straight piece of steel
bar(a few thousandths of an inch larger than the inside of your
brass tube) to very lightly expand the brass tube with.
Then after the tube has cooled, put it in the freezer overnight(unless of
course you have some dry ice) to shrink the tube. After shrinking the tube,
quickly remove from freezer, lightly coat the outside with a sealing
compound that can seal petrol(Hylomar Blue) & then refit to carb.
Hope this helps.
Re: loose carb nipple
Posted: 11 Apr 2010, 13:06
by kevtherev
your back firing is an air leak I would suspect..unless the timing has been dicked about.
leaks are common on the vacuum servo line (off the manifold)
the vacuum pipes to the distributor and air box (perished rubber) and any gasket attached to the carb.
assuming you have a pierburg as you don't say which engine
Re: loose carb nipple
Posted: 11 Apr 2010, 13:46
by albertramsbottom
Could be a perished servo t-piece as this was the cuase on mine
Cheers
Re: loose carb nipple
Posted: 11 Apr 2010, 13:58
by baldiebird
Garage replaced servo t piece. Hoses appear to be in reasonable condition. The brass fuel inlet pipe fits back into the carb easily but is loose. I am suspecting this could be the cause of the air leak. Does that sound sensible or am I talking Bol****s. Engine is 2L Aircooled with twin solex.
Re: loose carb nipple
Posted: 11 Apr 2010, 14:28
by baldiebird
I think I may have discovered the source of the air leak

I assume the air cleaner side arms are supposed to be fitted securely to the carbs. The right hand one was just sitting on top of the carb

It would appear when the van was serviced the garage couldn't be bothered to refit it correctly
or wouldn't this matter too much.