Greg Hutmacher wrote:
> The car is now running as well as it ever has, but there is one more
>mystery. In the book, it tells you to, with the engine warmed and running,
>remove the air cleaner and lift and hold each carb piston about a 1/4 inch
>with a screwdriver as a test of fuel/air mixture. If you are too lean, the
>car's idle will drop drastically and it will try to die. If you are too
>rich, the car's idle speed will increase. And if it is correct, I think it
>said the car's idle will momentarily increase and then return to normal.
>Using this test, I found my car was trying to stall when I lifted the carb
>piston. I adjusted the mixture needle all the way up into the piston to its
>stop at full rich position but the "lift the piston 1/4 inch" test still
>caused the idle to drop and falter. Why? What am I doing wrong? It did this
>on both carbs. Anyway, it doesn't really matter, I adjusted the needles to a
>point where the car is running very well regardless so I think I'll leave it
>alone. Thanks again to everyone for their help! Regards, Greg Hutmacher
Then Ed Woods wrote:
>Don't know what book you're using, but the one's I've read suggest
>moving the piston up only 1/32". I'd expect the engine to stall if I
>lifted the piston 1/4".
First of all, I should point out that this isn't the first I've heard that
the 1/4 inch lift is way too much. I've had guys tell me this before.
Secondly, damned if it isn't starting to look like they're right...
according to the 1/4 inch lift test, I have NEVER been able to get a rich
enough mixture. Greg seems to have had the same experience using this test.
I guess the question is, why is it wrong in the Bentley manual? And if it
IS wrong in the Bentley manual, then why the HELL does anyone use the
manual at all? The Bentley manual OUGHT to be the final authority for this
kind of stuff, save for a typo here and there. Are we saying that the
Triumph engineers didn't know what they were talking about?
Ed, I'm not meaning to "challenge" you here... I already said it looks like
you're right and that others have told me the same thing, but since it's
the Bentley manual that recommends 1/4 inch, I'd like to know what source
YOU have that says 1/32? Because I've only heard that through the
grapevine, so to speak... I've NEVER seen it in print anywhere.
I'm not your average male... I usually read directions, and follow them
closely, particularly when I don't know anything about what I'm doing.
That's how you learn... you assume FIRST that you DON'T know the answers
(even when you think you do) and then you read or experiment or whatever.
I'm not trying to challenge or offend anyone... just looking for the
objective answer. Where is it written that the piston ought to be lifted
only 1/32 of an inch, and why does the Bentley manual suggest 1/4 inch?
Pete Chadwell
1973 TR6
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