Hi Philip,
I've been told that the SU's must have oil in the dampers, otherwise the
engine will hunt. This sounds like what is happening. It could also be
mixture the big M word. It could also be carb sync too.
Now let me say beware. Always check the ignition, valve and timing first. I
have come to a rule "the Carbs are the last thing I touch." Too many people
start with the carbs when in fact it is something simple like wires or points
causing the problems. I would also check for the proverbial vacuum leak, they
will drive you nuts.
I just went through this on my MGB. It took almost 6 months to get all the
bugs out of the rebuild. It just takes time. It could still be the Carbs,
especially if you have rebuilt the engine or the carbs.
Good luck
Rick
Philip Hubbard wrote:
> I always think it's a good idea to keep the list updated after getting
> advice - besides, I'm still stuck! :) Here's the latest skinny.
>
> I spifffed up some spare 404 carbs (1 1/4" SUs) with new jets, needles,
> float bowl valves and gaskets and =a lot= of carb cleaner. Pistons drop
> nicely with a thunk.
>
> Put the carbs on and started her up. Runs smoother, but there is still a
> rising and falling of rpms - probably about 800-1000 rpm spread from
> highest to lowest, but they aren't almost dieing on the bottom end - at
> least with the choke out. I haven't done any tuning as I didn't get this
> far until kind of late last night and there's been no time tonight.
>
> My two concerns are:
> 1) obviously the continuing rise and fall, but could this maybe just be
> cured on tuning?
> 2) when I stopped the car after running for 5 minutes or so, I lifted the
> two pistons and found swirling smoke in the front carb - no seeming probs
> on the rear one.
>
> What could be causing this smoke? Same smokey front carb existed before
> switching the original carbs out.
>
> BTW, I never did find that piece of solder from the first bad poppet valve
> solder job, but I did take the opportunity to adjust the valve clearances
> while I had the cover off looking. I did it "cold" at .012 and found they
> were all a little loose, but not terribly so.
>
> Also, this last running I did without filling the carb dampers with oil.
> Will this make any real difference at idle?
>
> I'm starting to worry that some major rebuild may be in order. Did I ever
> mention that before I started doing all this work I found that the inside
> of the engine compartment on the carb side was quite oily? I'm wondering
> if there is a cracked block blowing out oil or a blown head gasket. I did
> replace the head gasket just a few months back though.
>
> Well, there's the update. Any advice is appreciated. :)
>
> Thanks,
> Philip
>
> 1974 Damask Red Midget - Arioch, Lord of Chaos
> 1960 BRG Bugeye Sprite - First up for restoration
> 1973 Damask Red Midget - Project car for sale
--
52 MGTD,Sparky 74 MGB, B-tris 76 XJ12 Coupe, Jacque
60 Bugeye, Puddles 58 MGA Coupe, Ruby
http://www.softcom.net/users/walters
http://www.geocities.com/Heartland/Acres/4644
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