More than likely the senario in this case. The rebuilder (not a professional)
may
have taken these apart and not made any attempt to reassemble them in the same
way
the parts were before. He may have mixed and matched at reassembly. I have
read in
the manuals that carefull attention to make sure the parts are put back
together on
the same carb they came off and piston housings should be put back on oriented
the
same way (mark them for this purpose). I'm afraid this mechanic friend of mine,
however well intentioned, is the kind of guy that will take parts off other
carb
sets and mix and match parts to make one complete set out of them. I have since
taken them apart a few times to fix leaks, re-align jet assemblies. etc., but
always
made sure that they went back together in the same order and orientation. I
guess
this does not help when they were not assembled from matching parts in the first
place.
Mike MacLean-60 Sprite
"Paul A. Asgeirsson" wrote:
> Hi Mike,
>
> There is a lot of mix and match that folks do on rebuilding SU carbs. You
>might
> be the recipient of this. Some of the items that are variable on these carbs
>are
> the internal dimensions of the air chamber, the external diameter of the
>piston,
> the weight of the pistons, the size of the air holes in the bodies. It's
>often
> the case you do everything right on a nice clean rebuild, but the two carbs
>might
> not be the same! Welcome to the delights of DPO carb rebuilds on a possible
>mix
> and match basis!
>
> Paul A
>
> Mike Maclean wrote:
>
> > I think I've got the tuning of the multiple S.U. carbs down pretty well
> > after rebuilding the jet assemblies twice, replacing the rear carb body,
> > shaft and butterfly and replacing all other gaskets in the carbs. It
> > amounts to rebuilding these carbs twice. I am stumped by the rear
> > carb. The mixture nut has to be screwed almost all the way up to get it
> > to lean out properly and idle will drop below 1500 rpm with the
> > adjustment screws all the way off the stops of both carbs. The needles
> > are correct for the S.U. H1 carbs (GG) and the jets are the correct .090
> > size and are new. What are some possible reasons for this?
> > Mike MacLean-60 Sprite
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