1982 Honda CM450A from United States of America


Takes a little while to warm up, but great power and acceleration


Bike wouldn't run off choke; carb cleaning and new breather filter fixed it.

Cylinder head bolts were rusted and broke when servicing valves and pistons.

Better sized tires would not fit without modification.

Stock setup runs too lean.

Charging system is too weak, so replaced bulbs with LEDs.

Takes a long time to warm up, even in summer.

Valves seals leak oil onto pistons during storage longer than a couple of weeks, but the seals are cheap to replace.

Valve tapping despite adjustment - same as another reviewer mentioned.

Hard to find a more comfortable seat.

Plastic carb floats are not adjustable, and leak depending on how the bike sits.

General Comments:

I actually have the CM450A Hondamatic. Bought it to commute in-town, and it's perfect for my needs.

Had it on the highway, and acceleration was no problem. RPMs are high compared to the manual bikes, so it's not exactly a highway bike, but it's good for short stretches. Wiggles around easily with even a modest breeze, but might just need thicker fork oil or service. It's lightweight, so it's a little rough over bumps, but not unbearable.

Breather filter was missing from the bottom of my air box, so my carbs kept clogging even after I pulled and cleaned them. Pulled them apart one last time, replaced all the rubber and cleared all the passages with carb cleaner and compressed air. Runs great now, even with the stock setup.

If you're feeling a little slow off the line, check and adjust the accelerator pump, and you'll be quick again. Runs too lean and temps are about the same with or without exhaust baffling, so I'll be trying a rejet soon. Has to be choked and takes a minute to warm up even in 100+ temps. Also needs a couple minutes of riding to have good acceleration.

Running LEDs for lights is a must if you want to replace the headlight with halogen.

Iridium plugs keep it purring smooth. Replaced the entire valve and cylinder head assembly for $75 with a used one online, so parts can be found, but check the manual first, because not everything is interchangeable. Cylmer manual and full Honda service manual have been necessary, since some info is missing out of one vs. the other.

Tried to shortcut and make gaskets, but buying complete gasket kits online saved me a bunch of time and money - CB450 from the same year will work.

The bike can be lowered using 11" shocks from Rebel or Harley, but the front end might also need to be dropped a couple inches at the trees.

Searched high and low for a seat, and tried several, but had to make one custom. The seat is very flat, but with good foam it rides perfect now. I hope I never have to let go of this bike, because as quick as it is, I can't see needing more power. Very fun bike to ride.

Would you buy another motorcycle from this manufacturer? Yes

Review Date: 15th August, 2011

7th Oct 2013, 19:16

I have a 1982 CM450A and I love it. I have been riding for many years, and presently have 2 excellent BMW's, but this is my favorite around town bike.

5th May 2020, 02:39

I just purchased a 1982 Honda CM450A and I was going to change the seat; where did you have yours made?