Jon Swanson writes -
>The PO had a newer intake manifold on my car, so since I had the
>carbs off anyways I got an old-style manifold that has all of the ports
>plugged with bolts and changed that over too to avoid any vacuum leaks.
>Should I replace the jets? Do I have the mixture
>set right? Like I said before, these
>are unknown carbs. I was planning on replacing the jets anyways, but wondered
>if I am on the right track?
>Do I need to replace the needles on the pistons too? They aren't bent and
>don't seem to be hitting anything....
>
>Another carb issue, I noticed that my throttle shaft bushings are worn, and was
>wondering if anyone has had success with the reamer/oversize shaft set
>from Moss?
>
Jon -
Since your engine responded so favorably to the carb work you've done so
far, I would do a full carb rebuild. And yes I would replace the needles
on the pistons too. If they are worn, when you lean them out enough to get
a good idle, they will starve the engine out on acceleration. (And it's
hard to detect this kind of wear, visually.) I have no experience with the
Moss throttle shaft bushing kits - ' got mine done by MG Matters
Restorations (Tim Handy).
Now - about that manifold. The HS4 intake and exhaust manifold flanges
are thicker than those designed for the HIF. If you switched the intake
manifold and retained the old exhaust manifold, either you did have a
manifold leak or you will have one now. The newer style (for HIFs) is the
correct manifold for the '73, so my guess is that you have the newer style
exhaust manifold also. This would mean that those studs holding both
manifolds are gripping only the intake manifold, while the exhaust
manifold is being held snug by the two end studs only. This may not affect
your immediate problem, but it does need to be addressed.
Given an engine in reasonable condition, I don't recall that one should
have to lean out 4 flats from the nominal 12-flat position - indeed this
might be the sign that those needles on the pistons are worn. With rebuilt
carbs, mine usually run pretty well in the 12-flat setting and I only have
to lean them another flat or two, if memory serves me correctly.
Keep us posted!
Allen Bachelder
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