Assessing a Honda 600 Coupe or Sedan that has not been running for years

The following is a reprint of a post made to the yahoo Honda 600 group by Bill Colford and others, that describes in detail the things to look for and isues to consider when buying a Honda 600 that has not run for some time...

I am assuming the Honda 600 in question was not put into long term storage
but rather simply parked and left.  If "Parked and Left" is the correct
assumption then you will have to check everything.

Fuel

The gas tank will have rust and should be removed and cleaned then a
two or three foot of chain tied to a length of rope and shaken inside the
tank for 20 or so minutes to loosen the rust pockets, then use a good tank
cleaner and then an etch to prep the surface for a tank sealer, I like to
use Hirsch Tank sealer. Remove the sending unit from the tank before using
the chain or sealing the tank.   Also while the sender is out of the tank,
bend the tabs on the side of the unit and use an eraser to clean up the
copper wire on the sender.  Then attach a Volt meter in the Ohm range and
move the float up and down to see if it is working properly.  If not make
sure the lead running across the wire coil is touching and making a good
contact, ensure your ground wire is attached and try the sender again.  When
reinstalling it do not use TV to seal it, just use a good quality gasket
material if the rubber seal is damaged.

The fuel pump may work but should be removed and cleaned, this can be
accomplished by removing the bottom plastic (where the in and out ports are)
and using a tooth brush clean it well because the gas will have left a goo
on the inner edges. Then clean all the lines, this may be as simple as using
compressed air and just blowing them out or locking a length of old cable to
a drill and running it through the lines, either way squirt some carb
cleaner in the lines and using compressed air blow them out again.  Then
pull your carb, turn it over and remove the 3 screws to the cover to the
accelerator pump and check out the diaphragm, if it is cracked it will need
to be replaced and Honda still has them. Next remove the bowl, and clean out
all the gum, remove the pin holding the floats (watch that the needle valve
does not fall out) and float test it to see if it does not leak. Then remove
the needle valve and valve seat, clean the screen by squirting carb cleaner
on the out side of the screen first and using compressed air to blow from
the outside in to remove any build up of gum. Use air to blow out everything
and put it back together. Next remove the solenoid check the OF ring and
touch the wires to the battery to see if the pin pulls back into the
solenoid, if it does then it is ok, if not then replace it. Pull the fuel
filter and replace it, you should be set for fuel.

Brakes

Caution, do not get in the car and try them, open your Master Brake
cylinder reservoir and look to see if there is fluid. If it has fluid, top
it off with fresh and bleed the brakes slowly until you have clear brake
fluid coming out of all wheel cylinders. If it is dry, remove the master
cylinder and open all the bolts, clips and fittings, then place the cylinder
in a bucket of clear water and leave it for several hours. Then, after all
the crystallized brake fluid is liquid again, start tanking it apart,
dipping it back into the water to clean all the parts. Mark down on a blank
sheet of paper which parts go where. The difference between the front and
rear check valves is the size of the holes, mark them as such when they are
removed. Open the cylinder and try tapping the housing against a block of
wood to move the pistons out. If they will not come, place the cylinder back
into the water and try again. CAUTION: don't use anything to poke around and
cause the rubber cups to be damaged. Close off the holes and use air at the
closed end (there the two keeper bolts are) and using compressed air (and
pointing it toward the water) blow them out of the cylinder.  Then wash
everything in water, use denatured alcohol to rinse all the internal parts
and rubber as a final cleaning agent. Use Lacquer thinner to rinse out the
cylinder and blow it dry with compressed air. Clean all the other parts and
check the rubber cups for cracks and chips or nicks. Look at the inside of
the cylinder and see if it is pock marked where it corroded. If it is
slight, use 1000 sand paper wrapped around a length (8 inches of 3/4 inch
hose) and turn it down into the cylinder and keep turning it as you remove
it. This should clean it enough to see if there are any deep pits. If there
are, it needs to be replaced and go to all the wheel cylinders and calipers
removing them and cleaning the same way in water.  Using water to clean
everything is really the key, brake fluid (DOT 3) is made to absorb water in
your system. Water liquefies the fluid and can keep the rubber in re-usable
condition. If the pits are too deep, then it will need to be sleeved in
brass. Do the same with the rear cylinders if they are pitted. The front
calipers can be cleaned and the rubber "O" ring replaced. Important issue
here is the pistons, if they have started to rust, they will have to be
reechoed, yes even if it is in an area that is not in the travel area of the
piston and the "O" ring. When reassembling use a rebuilding fluid on all the
rubber and metal surfaces. The power booster is another animal I take them
to a local rebuild to have them rebuilt.

Engine

 Drain the oil change the filter and refill it with 10W30 oil.  Next
open the distributor and change the points, check all wires because Mice
love to chew on them and a simple look will save all kinds of time and
frustration. Pull the plugs and see if they need to be changed. If you clean
them use a file or sand paper and reset them. Don't use carb cleaner.
(there are other things you could do) but these will give you a good start.
Put back to gather place a fresh battery in the car and see if it will fire
up.  If you need to set the timing look in the owners manual and follow the
instructions.

More notes from further posts to the group:

Miles is correct, remove the sending unit from the tank before using the
chain or sealing the tank.   Also while the sender is out of the tank, bend
the tabs on the side of the unit and use an eraser to clean up the copper
wire on the sender.  Then attach a Volt meter in the Ohm range and move the
float up and down to see if it is working properly.  If not make sure the
lead running across the wire coil is touching and making a good contact,
ensure your ground wire is attached and try the sender again.  When
reinstalling it do not use TV to seal it, just use a good quality gasket
material if the rubber seal is damaged.

Greg Sikes makes a good case for the cylinders, marvels mystery oil is a
true cure for stuck pistons.  However if the plugs were out then getting the
pistons loose is necessary to get the cylinders off.  But if the pistons
were stuck then all the miracle cures on earth will not replace the damaged
cylinders.   The cylinders must be removed,  the pistons removed from the
rods and all of the rings removed form the piston cleaned and the cylinders
cleaned with 1000 grit wet dry sand paper and a light oil, (yes marvels will
work) and clean the cylinders moving in circles instead of up and down.
Clean them again with soap and water to remove all grit from the sand paper.
Now place the rings in the cylinder without the pistons, and measure the gap
between the two ends.  Then clean the outside of the pistons and take
special care on the grooves for the rings.  Often the rings will seize in
the grooves of the pistons and collapse inplace.   Normally this is the Oil
ring and if you do not fix it you will look like the blue streak.  If the
rings measure out ok, then put them back on the pistons and reassemble the
engine.

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