OK group - I'm stumped, frustrated, and begging for direction. I've
never gotten my 75 TR6 to run correctly - it always missed and stumbled.
It was tired, so I did an engine refresh with redone head, rings, and
bearings (both con rod and main). Now my compression is 130 across the
board. After starting it up, it still missed badly. I added the Ignitor
electronic ignition (thanks rgb), but it only helped slightly. So, now I
am almost positive it is carb related.
Here's why I believe that is the case: I was able to heavily restrict
(with my hands) the amount of air going into the carb intakes and get it
to run much better. The rpms would raise from 800 to approx 2000, and
miss would almost disappear.
Alright - I thought major vacuum leak. So, I plugged off all vacuum
hoses to carbs and even covered those holes in the carb's face that
sometimes allow air to get around the venturi. (Let me add before I go
on that I rebuilt the carbs last fall before the refresh. Shaft seals
are good - very little if any air leakage. And plate rotation was clean)
So, rpms raised up and it missed less, but it still missed. I backed
off the idle adjustment screws all the way and noticed that I cannot in
any way balance the carbs. Rear pull is much, much less that front carb.
This was a problem even before engine refresh. I'm quite sure that
manifold gasket is not the problem.
So, I don't know where to go from here. What am I missing and can you
think of any reason carbs won't balance? I sincerely thank you in
advance.
Carl Huppert
Baltimore
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