This
carb is from Glen’s 83 Vision. He bought it from a friend after it had
been sitting for six years. The bike was "running great when it was put
up" but after that length of time the fuel in the bowl had turned to
jelly, then dried up. In addition moisture in the air had caused some
minor rust.
Glen cleaned out the carb with carb spray, changed the
oil, drive fluid, plugs etc, and tried to fire it up. No mater what he
tried it wouldn’t start. Into the shop it went. The technician cleaned the
carbs again, working on it for a week, finally concluding that the front
carb wasn’t drawing fuel, due to worn valves. Needless to say Glen was not
happy when he saw the estimate.
Glen contacted The ROV Forum looking for suggestions. The
response was impressive, with the consensus that his problem was one of
fuel delivery. Glen mentioned that he lived nearby, so I suggested that he
bring the bike over and we could figure it out.
The next day Glen
arrived with a U-haul, with the bike in the back. He rolled the bike down
the ramp, and we got to work.
Listening to the bike trying to
start, my first thought was that the carbs were out of sync. It WANTED to
start. We checked all the basic stuff, making sure the bowls were getting
fuel, checking the pump shot, operational choke, etc. With a shot of
Gum-out , the engine would start and run well, if only for a few seconds.
Still thinking the problem was in the sync, we started adjusting the sync
rod in 1/8 turn increments. It seemed to get better, and if we cranked the
throttle a few times, the bike would run for several seconds, but
poorly.
On a hunch, I thought I’d try to give the pilot mix
adjustment screws a turn, and Lo and behold, they were frozen solid. They
were so tight, the slots for the screwdriver was getting
destroyed.
We pulled the carbs and soaked the screws in PB Blaster
for a couple of days. For those of you who don’t know, PB Blaster is an
incredibly effective penetrating spray. I have seen it loosen exhaust nuts
that were so frozen that the flats of the nut was rusted away.
Because the adjusters were frozen, the slots for the screws were
unusable I pulled the access plugs over the needle assemblies, and
the rear one was full
of crud, the front looked clean.
The solution
was to remove part of the boss around the head of the adjuster
in
order to recut the slot with a Dremel tool.
Once I had done this, I
picked a screwdriver that fit well into the slot, put a
large
Vice-grips on the handle of the screwdriver for leverage and
S-L-O-W--L-Y turned the rear screw out. The pin assembly was in very
good
condition. The same procedure was used on the clogged front
adjuster,
and fortunately it also came out. the pin came clean easily,
but the passage
was pretty clogged. (Ok, thats why it won't run!!
:) |
