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Carb Popping

Posted: 29 Sep 2011, 19:28
by kevmilko
Hi all got a prob with the popping noise from the carb on my T25 1985 model did an oil change 2 weeks ago and did slightly over fill :oops: have taken carb off stripped and cleaned it. Loads of oil in carb but all clean now but the popping hasn't stopped. Any ideas please. Kev

Re: Carb Popping

Posted: 29 Sep 2011, 20:33
by BOXY
How did the oil get into the carb? If it got pushed out the crankcase breather, try cleaning / replacing the air filter.

Re: Carb Popping

Posted: 30 Sep 2011, 16:55
by kevmilko
BOXY wrote:How did the oil get into the carb? If it got pushed out the crankcase breather, try cleaning / replacing the air filter.
Thank's BOXY Have done as you suggested replaced air filter. Also took carb back off and replaced Gaskets had Timing checked but still got the same problem. Thinking now to get a compression test fingers crossed it's a good result thank's again. Kev :ok

Re: Carb Popping

Posted: 02 Oct 2011, 08:50
by kevmilko
Compression test has been done results not to bad No's 1 and 3 = 145 No. 2 =135 No. 4 =130. Still getting popping noise tho. When taking HT lead off of plug No.4 noise does stop. Any ideas please. Kev :ok

Re: Carb Popping

Posted: 02 Oct 2011, 09:21
by kevtherev
when the lead is removed does the engine mis fire and start to shake on the mounts or does it just carry on without the noise?

Re: Carb Popping

Posted: 02 Oct 2011, 09:43
by kevmilko
kevtherev wrote:when the lead is removed does the engine mis fire and start to shake on the mounts or does it just carry on without the noise?
Hi Kev the engine runs normal and without the noise.

Re: Carb Popping

Posted: 02 Oct 2011, 09:51
by kevtherev
then it's misfiring and you should treat it as such
mise fire is ...
poor spark
poor compression
weak mixture

causes for this are
plugs
leads
air leaks
burnt valve(s)
broken piston ring.

the popping noise is the spark igniting the fuel in the cylinder, a weak mixture will pop. as will poor compression

Take off lead No 1 and see what happens

is the brake servo hose the braided type?

Re: Carb Popping

Posted: 02 Oct 2011, 10:14
by kevmilko
Kev have taken off No.1 and popping is still there also brake hose is the braided type. Thank's

Re: Carb Popping

Posted: 02 Oct 2011, 12:40
by kevtherev
when you took No 1 lead off what happened to the engine .. did it falter and run rough

Re: Carb Popping

Posted: 03 Oct 2011, 14:49
by kevmilko
Hi again Kev sorry in delay of replying, think I have found the problem. Stripped near side down and found that the push rod is not giving enough pressure onto one of the tappets. Think this could be the problem.. :( Kev