Topica Loopframe_Guzzi Archive


Subject: RE: "Snap, Crackle and POP"

Author: plainjs

Date: Aug 9, 2004, 9:13 PM

Post ID: 1717317884



Thanks Charlie your idea just about explains it the way I experienced
it, the valve must have been impeded from closing all the way but not
enough to prevent detonation, otherwise it would have been real
noticably running on one cylinder only. The noise then was air being
sucked in and out of the silencer or carb depending on which valve, when
the "crap" (technical term)dislodged itself the valve slammed shut and
everything returned to normal.

Nick (from PRC) said he had a similar situation with his Chiang
(spelling?), he thought it might be that a tight valve stuck then
released once the cylinder head cooled down, but the affected cylinder
would not be firing if that were the case, no? It certainly didn't feel
as if it was only firing on one. When it cleared itself there was no
backfire, just a very noticable impact.

I guess I'll just have to run the thing harder in the future, hey it's a
tough job but someone has to do it!!!



..john




Charlie Mullendore wrote:
 
Hi John,
You might have loosened a chunk of carbon in the combustion chamber and
it hung a valve partially open for a bit. My old Gravely "T" head
tractors do this ocassionally when used hard after "putt-around" work.
Cheers,

plainjs wrote:
 
74 Eldorado, 35k, stock as far as I know but I've had the bike only a
few months and 3k miles. I got engaged in a little duel from the lights
and hear 2 massive backfires as I change up into 4th gear, scared the
shite out of me, (and the 2 clowns in the Mazda who look as they think
I'm now shooting at them!). As I roll to a halt at the next light I hear


this wierd noise coming from the samer side as the backfire, the bike
feels as if it's OK (though I'm nursing the throttle now) the noise is
sort of soft, (like a buch of marbles rolling around in a bucket),
obviously not good but it's not scary enough to shut the bike down
immediately, a short while later I hear/feel a loudish "bang" and the
bike is back to normal again. A case of Heineken for the best
explanation??????

..john
Ps I've posted this on Wildgoose too.

To err is human, to "Eh" is Canadian.



Charlie
http://members.tripod.com/charlesmullendore/index.htm



To err is human, to "Eh" is Canadian.

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