HONDA CA160

Well, It is hard to believe that a 1968 Honda only has 3k miles on it unless it has been in somebodies barn, as a memento to some unfortunately deceased individual, But here are my suggestions regarding your problem.

The sifting linkage is out of adjustment, (external) or possibly worn and thus unable to keep the gears properly aligned, or maybe a bent shifting fork or if the fork is directional maybe it is installed backward, therefore not able to function properly.

The original driver drove the car in 1st gear forever and the gears are worn out. Maybe the original driver couldn't handle the stick/clutch shifting deal and screwed up the edges of both the 1st gear and the first gear in the counter/primary shaft and the taper of the gears no longer is an acceptable condition.

If you cannot determine just what the problem is, I suggest you order a rebuilt tranny and use the one you have as the core replacement.

Life is to short to spend it worrying about being stuck in traffic.

TMF

It's a motorcycle, not a car.

Is the chain adjusted properly?

Google honda motorcycle forums

Honda may still have the parts. if not buy a engine and use the gear parts. You will need a dog and a gear.

I used to own the same bike back in '68. The transmission is purity stout, the clutch, however, isn't. Starting in first gear puts a greater load on the clutch. Change the adjustment on the clutch to engage more, there should only be about a inch of travel from full engagement to no engagement. Also Honda used a multi-plate wet clutch, make sure you have enough of the right kind of oil.

Good luck, I blew-up my bike twice before moving to a larger size motorcycle.

Thanks, I had originally suspected the clutch, but pretty much ruled it out. This 1st gear problem shows itself with even the very lightest of throttle. I can take off in 2nd with VERY heavy throttle putting much more torque on the clutch without any problem. The more thought I put into this problem along with reader's help leads me to think that the problem lies with the shifting forks. Many thanks for you input.

sounds very much like contaminated clutch linings or fluid. But it could also be chipped first gear cog, weak or missing clutch springs, faulty shifter detent.

I would flush well, use correct (not close, but exact specified oil, exact quantity listed in manual), and do 15 minutes of high rev. slipping clutch take-offs. (drain, refill, enjoy)

The cause of the gear disengagement is a bent, worn, or improperly shimmed shifter fork. If you continue to ride with this condition you will round the engagement dogs of the gears. Honda makes a near bulletproof motorcycle. I would suspect the root cause to be an abusive owner stomping the bike into first gear without using the clutch to get the underpowered thing to wheelie.

I have used the oven in my kitchen to preheat the engine cases to 150 deg. to allow for easier disassembly. I do not recommend this practice, it makes the entire house smell of gear oil.