Tuesday, May 5, 2015

1966 Honda CB160

Isn't this the cheekiest thing you've seen in a while?   It's a 1966 Honda CB160 that has been in the same family since new.  The finish is completely original, as is almost everything else about the bike.
At some point the front fender was changed for a chromed part from a Kawasaki and the mufflers were swapped for reasons unknown.  The owner (the original owner's grandson) is currently searching for the correct fender and mufflers and intends to keep the bike so that he can pass it along.

It has been sitting in indoor storage since 1983 and so needs some attention to get it running and running well.

The owner had already installed a new battery but the bike wasn't running right.  In this kind of situation (as in any other), being methodical pays off.  So, in order, here is what was done to get this bike back to its intended mission of making its owner smile.

 - Removed the plugs and made certain that the engine spins freely
 - Set intake and exhaust valve clearances
 - Perform compression test
 - Verify engine oil level
Ignition System:
 - Verify battery voltage
 - Clean breaker points and set proper gap
 - Verify auto advance functions freely
 - Set ignition timing (statically, using a test light)
 - Clean spark plugs and set proper gap
 - Visually verify spark at the plugs
Fuel System:
 - Drain all old fuel
 - Replace all rubber lines
 - Disassemble and clean/inspect carburetors

It was in the fuel system, specifically the carburetors, that age-related deterioration showed itself.
The floats in these old Hondas were fabricated from brass sheet and soft-soldered together.  The float's function is to control the inlet valve in the carburetor.  When the fuel level in the carb bowl drops, the float also drops with it, thus opening the inlet valve and allowing fuel into the bowl.  The float then rises and closes the inlet valve when the fuel level reaches the proper height.
Here we can see the effects of surface corrosion on the floats.  The brass is very thin originally and it doesn't take much for corrosion to cause perforation, allowing fuel to enter the float and negating its ability to actually float.  The corroded areas pushed right through with the lightest touch of an X-acto knife.  Needless to say, these parts were replaced with new, OEM parts (still available).
The carbs were cleaned and reassembled, the new floats installed and set to their proper height and the carbs were then reinstalled with new fuel lines.
The bike started with no trouble and the idle speed and idle mixture were set once warmed up.  The final step was to synchronize the throttles so that the slides lift at the same time.

Some other minor "repairs" had to be corrected, such as the brake light switch's attachment to the pedal (rusty wire won't do)...

...and the choke linkage (more rusty wire).

The air filter hardware was also replaced with the correct type.  The little Honda runs like a champ and will no doubt continue to do so for quite a while longer.


No comments:

Post a Comment