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carb problem?

Posted: 26 Jul 2013, 08:58
by monkeyboysee
hi all,

had a long trip to and around Cheshire, yesterday i noticed a popping sound, particularly when going down hill and easing off the gas. also sounds a bit more "tinny" when idling.

the engine has sounded a lot better since the exhaust was replaced, and i redid the fuel line and filter, so its noticeable to me.

i haven't got round to points / rotor arm yet could it be that?

Re: carb problem?

Posted: 26 Jul 2013, 09:00
by monkeyboysee
1981 16OOCT Aircooled BTW

Re: carb problem?

Posted: 26 Jul 2013, 09:08
by ghost123uk
The most common cause of that symptom is an air leak somewhere in the exhaust system, and you mention it was recently replaced, perhaps there is a connection ? Lack of gaskets or loose bolts / joins ?

Very unlikely to do with the ignition system btw.

E D I T = spelling ! = an air leek, veg in the exhaust :roll:

Re: carb problem?

Posted: 26 Jul 2013, 10:38
by kevtherev
if there's no problem with the exhaust then the air leak is on the inlet side

Re: carb problem?

Posted: 27 Jul 2013, 20:05
by monkeyboysee
ghost123uk wrote:The most common cause of that symptom is an air leak somewhere in the exhaust system, and you mention it was recently replaced, perhaps there is a connection ? Lack of gaskets or loose bolts / joins ?

Very unlikely to do with the ignition system btw.

E D I T = spelling ! = an air leek, veg in the exhaust :roll:

you might be right, just had time for a very quick shufty, one piece of the exhaust is a bit loose, its a piece with the wraparound coupling? i'll get under there first thing and tighten up, see what occurs. I think we're going through to Dub odyssey for a look so should find out on the run if that's the problem or not.

cheers buddy

Re: carb problem?

Posted: 28 Jul 2013, 14:42
by monkeyboysee
monkeyboysee wrote:
ghost123uk wrote:The most common cause of that symptom is an air leak somewhere in the exhaust system, and you mention it was recently replaced, perhaps there is a connection ? Lack of gaskets or loose bolts / joins ?

Very unlikely to do with the ignition system btw.

E D I T = spelling ! = an air leek, veg in the exhaust :roll:

you might be right, just had time for a very quick shufty, one piece of the exhaust is a bit loose, its a piece with the wraparound coupling? i'll get under there first thing and tighten up, see what occurs. I think we're going through to Dub odyssey for a look so should find out on the run if that's the problem or not.

cheers buddy

update, tightened the offending clip, everything all in place, still got the same problem.

any further ideas anyone? next step?

Re: carb problem?

Posted: 28 Jul 2013, 16:16
by kevtherev
my idea no good then

Re: carb problem?

Posted: 28 Jul 2013, 16:53
by monkeyboysee
update no.2, rain stopped enough for me to have another gander.

i got under with engine going, i've got quite a bit of air coming out of the exhaust somehwere, but no obvious rust holes etc. it seems strongest around one of the heat exchangers, theres a bit of tube goes in, looks like it doesn't connect, hope you understand which one; seems to be coming from there maybe, but does seem to be coming from 2 or 3 places as the exhaust seems to eddy around the different parts.

my thoughts are to gun gum around the different areas until i find the right one, process of elimination? sound reasonable?