Subject: Re: TR6 backfire from carbutretor
> Doug,
>
> It's interesting that you bring up this problem. It may well be a stuck
> valve. Here why I say this. A few weeks ago several of the guys who race
> Triumphs got together at the Mitty in Atlanta, Ga. for several days of
fun.
> One of the TR 4's had recently rebuilt their engine and had new valve
guides
> installed. I believe they were bronze guides. They were not honed properly
> and the clearance of the valve to the guide was too tight and exactly what
> you suspect is happening to your new engine happened to him. One or
several
> valves were stuck when the engine got good and hot. It may well have been
> overheating because of a stuck thermostat as well. I believe there were
also
> valve seals installed which were never there in the first place.
>
> So do look for seals that should not be there, a too hot condition which
> would not be unusual for a fresh and tight engine and if your rebuild of
the
> head included bronze guides that don't have sufficient clearance.
>
> Just a little information in support of that comment that you found via
the
> net.
>
> It should be easy to spot with the valve cover removed.
>
> JVV
>
> ----- Original Message -----
> From: "Doug Nicotera" <dougnicotera@comcast.net>
> To: <triumphs@autox.team.net>
> Sent: Tuesday, May 10, 2005 5:09 PM
> Subject: TR6 backfire from carbutretor
>
>
> > Friends,
> > I was driving my '73 TR6 around town and it started to backfire
> sporadically
> > from under the hood.... just like that, out of nowhere. It had been
> running
> > fine up until then. I made it home, but the backfiring became very
> regular.
> > Upon inspection, I found that it was coming from the rear carb.
> >
> > I tried the obvious-- pulled the carb, checked it out and everything
seems
> > fine. Checked coil, ignition wires, distributor, timing, & plugs. Please
> note
> > that the motor has less than a couple hundred miles on it since being
> rebuilt
> > last year.
> >
> > I did a quick Google search and found articles that allude to a stuck
> intake
> > valve. Can this be expected so soon after a rebuild, or is there
something
> > else to look at?
> >
> > Thanks in advance!
> > Doug Nicotera
> > Harrisburg PA
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