Thanks Dick and Walt. I readjusted the carbs per the Bentley manual, which
matches up with what you stated. I seem to have gotten rid of the back
firing on the front carb. I belive it was resetting the idle with the choke
and carb linkage completely disengaged. I then adjusted the idle, hooked
the carb linkage back up and it seems much better. Now I need to get a carb
mixture adjusting tool since they seem to be running a ltitle weak in the
mixture. When I moved each carb piston up 1/4 inch at idle speed , the idle
dropped slightly. This was in the Bentley manual too.
Thanks again for your very helpful suggestions and patience with a mechanic
wannabe.
Jim Henningsen
Kissimmee, FL
75 TR6 CF35914U
80 TR7
Sally or Dick Taylor wrote:
> Jim---Check out the areas that Walt recommended. They are reasonable and
> consistant with some of what you describe.
> To further check on what might be causing one carb piston to lag behind
> the other, do the following:
>
> Be sure both choke cables have no influence on the idle, even when the
> choke is pushed in.
>
> Loosen the bolt that clamps the two carb linkages together. Adjust the
> idle on both carbs independantly. The vacuum 'pull' on each should be
> identical.
>
> Now, when you tighten the previously loosened linkage clamp screw, both
> air pistons should rise equally, as rpms go up. If they don't, it's
> possible that the linkage is not operating the throttle plates equally,
> due to play in the pin, set screw or whatever means used to assure each
> carb throttle plate opens the same amount. If such is the case, you can
> either correct the cause of play in this connection, or loosen the
> previously mentioned linkage clamp screw, twist the linkage to allow for
> the lost motion, then retighten the clamp.
> Do this till both air pistons rise equally, as dictated by the throttle
> linkage.
>
> It's also possible that the carbs internals are not set up the same. At
> this point, we do not know for sure which one is correct. Sometimes
> reading the spark plugs gives us a clue.
>
> I no longer use the stock linkage, so I may have left out a detail here.
> That's why it is always good to have a copy of the Haynes manual handy
> when carrying out such adjustments. Let me know how you make out here.
>
> Dick T.
> '73
--
Jim Henningsen
email:jdhenn@cfl.rr.com
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