Hi all:
My 1725 engine was rebuilt this summer. I finally got it back in Ol' Blue
this past weekend. Here's the mystery: The engine will start, but runs
only with power on cylinders 1 and 2 --------- 3 and 4 have minimal power -
you can pull off the plug wires on 3 & 4 while running and there is very
little change in rpm. I need to run partial choke and keep rpms at 2000 in
order to keep the engine running. I suspect this is due to the significant
drag on 3 & 4. I have changed spark plugs, plug wires, reset the valve gap,
checked and rechecked the timing - all to no avail. I blew out the gas
lines. I removed the manifold to insure there was no blockage in the
manifold or in the cylinder head. I have a nearly full gas tank. I have to
admit, that after 30 years of Alpine ownership and successfully dealing with
a variety of challenges, I am stumped!
compression - 175 or so on all 4 cylinders
valve gaps set cold to 15 thousands on all valves - I've done this before so
that I'm in the ball park to get the engine started - then when properly
warmed up I reset to factory specs.
ignition spark - normal as far as I can tell - it will shoot a gap over an
inch long - Pertronix ignition w/Pertronix coil
Autolite plugs - new condition - plug wires in new condition - new
distributor cap - even tried an old one - no difference
timing - about 7 degrees advanced - starts readily - even on 2 cylinders!
fuel distribution through a Weber 32/36 and electric fuel pump. All lines
cleaned, fuel flow is excellent to the carb.
gas tanks are nearly full of premium gasoline
checked the valves while engine was running - there is up and down motion on
all intake and exhaust valves. Rechecked the valve gaps with pistons at TDC
before compression stroke (did this on each cylinder)
what am I missing????? This is really frustrating as the distributor,
plugs, plug wires, manifold and carb were removed from the spare engine I
pulled out of Ol' Blue. It was working just fine when I shut it down and
they were only off an engine for an overnight. I am stumped!
Dr. Paul Almjeld
Department of Music
Dakota Wesleyan University
Mitchell, SD 57301
palmjeld@dwu.edu
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