I just picked up this 1975 Honda CB125, it's all original with 1900 miles on it. It has been garage keep and not run for over 25 years. What would be the steps I need to take to get it running again? Do I need to clean the tank and carb? And how would I do that, Seafoam??? I am no mechanic but would love to learn.

Bill:

The first thing you need to do is send it to me...

If not, and the motor still turns over with a kick and is not frozen up.

Check the interior of the tank for rust. If it's there, then you have a couple of options. Seal it or replace it. If it's clean, then fill it up a bit and see that the fuel lines don't leak and the petcock(s) still work. I'm sure there's a filter or two that probably need to be replaced.

Spark Plugs (replace). Most likely you'll want to replace the plug wires, too.

Oil Change (may have an interior filter/sump).

Tires

Good find.


Rich

Thanks Rich,
I got it for 150 and it does turn over. How do you seal a tank if it has rust?

Sealing a tank is fairly easy. It has to be drained and cleaned first. Then sealed from the inside. You can get a kit at your local part store or online.

I suggest changing all of the fluids. Especially the brake fluid. After sitting for that long it likely has moisture in it. After changing the oil but before installing a new spark plug, put a few drops of oil or 3-in-1 oil into the cylinder. Kick it over a few times with the plug out. The oil will help protect the piston and cylinder wall while the new motor oil is circulated through the motor as you're kicking it over. After you get it started and run for a while check the oil and plug again. You might need to change them again fairly soon as the old gunk gets worked out. The carb might need a cleaning too.

Have fun with it. Those bikes will run a long time but you need to change the oil often.

Thanks for all the info guys, one more question. What should I use to clean the engine, I don't want to discolor the metal?

Bill:

A can of spray degreaser won't cause you any harm.

If you spray it on a warm motor and hose it off, it'll clean up pretty good.


Rich

Really nice find.

Great looking bike. I have gotten several old Hondas running after them sitting for years. It is a lot of fun and riding them after is a lot of fun too.

Look in the tank with a flashlight. If there is a lot of rust you will have to clean it out. The carb is really simple, but will have to be cleaned up. You can use carb cleaner from the auto parts store. Take the carb apart, spray with carb cleaner and make sure all of the jets are clean. You will probably not need new carb parts, but they are still available for Hondas.

Put on new gas lines, plugs and change the oil. Change the brake fluid. Clean out the brake fluid tank on the handle bars really good. The brake pistons are probably frozen, but can the taken apart, cleaned up and probably (maybe not) put back together without new parts. Lube the clutch, gas and brakes lines.

Good luck.

Very nice vintage bike! Have fun with it!

Gosh, I was gonna chime in, and begin with the tank and rust inside it first, too, but it would appear the first matters have already been covered... go for it, and get right back to us. It can be a bit of a challenge for a non-mechanic, but you might surprise yourself at how fast you can pick it up.

I have an opportunity to possibly acquire a similar find with just 279 miles on it. I'm going to have a look at it tomorrow morning.