QuestionHello
two questions...I have a 1978 Honda Twinstar cm185, I know it is a 6volt system....what would be involved in converting it over to 12v?
and lastly...what would be the proper way to start the bike if it has sat for a bit...year or two
thanks
AnswerHi Allan,
The conversion to 12 volt can be done
in various ways. Of course you will
need a 12 volt battery that will
fit in your battery holder.
The headlight sealed beam and all other bulbs
will have to be replaced.
The 1981 CM200 has a twelve volt system
so most of the parts from it will likely work
if you can find them. The CB350 may be
similar as well.
The ignition coils may need replacement
and possibly the ignition condensors.
If your AC generator or stator coils
can produce over 13 volts AC
then you might be able to just add a 12 volt regulator.
The best place for these are the new chinese
bikes which use small, cheap regulator
that can just connect to your system
and run the excess voltage to ground.
Snowmobiles also used a small regulator
like this in the past.
Your 6 volt starter motor can be used if you
do not crank it for long periods.
It might burn out if cranked excessively at 12 volts.
The power coming from your stator is alternating
current. This has to be converted to
direct current by a rectifier before
it can be used to charge the battery.
What older bikes often did was use a rectifier
to convert to AC voltage and then they
just balanced the voltage by the
systems power draw. That means that
all the bulbs had to be working or the
current would get too high and burn
things out. Some bikes had a rectifier
and a full regulator.
Now a regulator is normally used to
regulate the total output of the
system.
You can try using the rectifier you have
but it might burn out eventually from
the 12 volts. The chinese make
small cheap 12 volt regulator/rectifiers all
in one that might be used.
The important thing is to change the bulbs
and then rectify/regulate the voltage to the new
battery. If the stator is weak you
would need a 12 volt stator(CB350?) or heavier
rewind of your present stator coils.
http://www.regulatorrectifier.com/catalog/1960-1979-Honda-Twin-star-CM185-Twinst...
Hope I am not confusing you but the options
are varied so I want to list them all.
For running the bike after sitting
I would soak the carb in Yamaha carb
cleaner and then blow out all the jets
and passageways.
Old fuel can really plug things up.
Add a small amount of oil to the spark plug hole
and turn the engine over slowly to oil it up a bit.
Check the battery, fuses, tires and rear chain.
Connector plugs can corrode so some
true electronic cleaner spray is
handy to have. (DeOxit)
Add fresh fuel and rinse the tank and
fuel lines. Add a small fuel filter to
prevent rust from entering the carb.
Check the fuel lines for cracks.
Check the air filter is not home to any rodents etc.
Change the oil soon.
Clean spark plugs or replace.
Contact points may need cleaning or replacement.
Let me know if you need clarification on anything.
Good luck!
Wayne S.
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