Thursday, April 16, 2009
1974 Honda CB125S
Another bike with very few miles on the odometer that made its way into Barry's garage for some restoration. It was first seen on Craigslist, then on eBay, where it was snagged for slightly less than the seller was asking on Craigslist. New tires (of course), new clutch and throttle cables, and a new ignition switch cable were the first changes. The carb was cleaned and adjusted, the timing chain tension adjusted, and now it starts on the first kick and runs strong. (It's getting a tuneup and detailing now and then owner Mike is putting it up for sale.)
The CB125S is a simple OHC thumper that was imported into the US from 1973 to 1985. It'll cruise at 55, and easily gets 100mpg at slower speeds. These bikes will last for many years so long as you're absolutely religious about changing the oil at least every 1000 miles- preferably every 700. The one weak point of the engine is the cam shaft bearings, which are simple journal bearings machined into the head. Once they wear, you can either have the heads machined to take roller bearings- a project that will cost several hundred dollars- or simply find a new head.
The CB125S was replaced in Asia and Europe with the CG125, and almost identical motorcycle that featured a simpler pushrod OHV engine in place of the CB's OHC engine. This was reportedly done to make the bike more rugged for use in the third world, where oil changes can be an expensive luxury. The CG125 engine develops slightly less power, but top speed and mileage are similar.