Michael, if your timing & timing marks are in the correct position , there's
no reason for it to backfire through the carb. I'm not up to date with your
problem, so bear with me if I repeat some things you've probably checked
already.It sounds like a timing problem. If it's a new engine, or a new cam
or timing gears,then the most obvious and most likely is the cam is timed
incorrectly. At one time, we had the race cam on our SPIT 1300 set 18
degrees advanced with no damage to the valves (even at 12:1compression), so
it can be set that far off, or more, without interference. The next greatest
possibility is that you've got a bad intake valve. If it's not a new engine,
then this is highly possible. Have you checked for carbon tracking inside
the distributor cap? There are more possibilities, but these have the
greatest likelihood of being the problem IMHO
Mark Haynes
'65 SPIT RMVR #162
'62 HAN6 Sprite
> -----Original Message-----
> From: Michael Graziano [SMTP:mgrazian@ltcm.com]
> Sent: Monday, April 12, 1999 2:13 PM
> To: 'Spitfires'
> Subject: Valve Adjustment take 2
>
>
> Hey folks.
>
> I checked and readjusted the valves on my Midget 1500 this weekend. A few
>
> questions arose. I think the valve gaps were in OK shape. They were
> supposed
> to be set at 0.010 inches. I found some that were as far open as 0.013.
> Does
> that make a significant difference? Is it OK to reuse the gasket as it
> was
> in
> good shape, and I used some permatex black gasket glue to help with the
> seal.
> I have a new one that I bought for the job, but misplaced it.
>
> Also, the intake was still backfiring. I rechecked for leaks on the
> intake
> manifold. Nothing found (doesn't mean nothing there). I enrichened the
> mixture a little. Now the exhaust smells a little like gas, and it still
> backfires throught the carb (ZS). Nearly scared the S#$% out of myself
> when
> I had my
> hand outside the carb barrel and it backfired.
>
> I've got the timing at 10BTDC, from Bentley's and Haynes. Should I
> advance
> it more or less as the next test (or should I test something else first).
> And if I advance it, is that more towards 12BTDC or 8BTDC.
>
> I'm determined to solve this damm thing. Even if I have to take a shotgun
> to the engine. At least it won't backfire anymore. ;-)
>
> Mike
>
> BTW: I changed the accelerator cable with one from a bicycle brake. I
> can't believe what a difference it makes. ANd for only $3.
>
> '78 Midget
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