Back in 1972, Honda determined that its immensely successful CB/CL350 OHC twin should continue to move forward…albeit slowly. But just how much change can be made by increasing the number on the side covers by 10, from 350 to 360? Quite a lot, as it turned out.
The 360 was no minor upgrade from the 350. It had a new chassis and some new running gear. The old 350 in actuality was only 325cc, with a 67mm bore, 50.6mm stroke; Honda enlarged the bore by 2mm and got the engine up to 356cc.
Change is necessary. A product sells, sells well, but when there is competition any sensible capitalist knows that the R&D boys and girls had better earn their salaries. In ’74, Kawasaki had both the KZ400 twin and the S3 400cc triple. Suzuki had the TS400 twin and GT380 triple. While Yamaha had the kick-butt RD350 twin. Honda already had the CB400F four-banger in the pipeline for ’75, and trusted it would put the company at the head of the pack.
Honda presented three 360 models for 1974, all under $1,000. The CL street scrambler ran for two years, 1974-1975; the plain CB, with drum front brake, for one year, 1974; the CB/G, with a disc front brake, for one, 1974. The CL had the “American-style” upswept pipes running along the left side, a 2.9-gallon gas tank and drum brakes fore and aft.
Road testers of the time had varied opinions as to the rideability of the 360. The one constant complaint was about the vibration of the 180-degree twin. The 350 had been a shaker, and the 360 wasn’t any better. Also, the engine had been detuned in order to enhance the torque, so while the 350 boasted 36 horses at 10,000 rpm, the 360 was down to 34 at 9,000. Honda felt that this less-peaky engine would make the bike more fun to ride around town. It was definitely a short-haul machine, as nobody seemed to like the saddle for long trips.
Internally the bearings on the crankshaft had been strengthened, and those who enjoyed abusing their engines were less concerned about bottom-end problems…not that the 350 had really had any. More important to the home mechanic, and most owners of the 350 who did not have the money to pay a professional, the obnoxious oil slinger that passed the lubricant through a filter was redesigned to make access to, and replacement of, the cleanable filter much easier. The whole oiling system had been substantially changed, using a “trochoidal” pump that utilized pressure rather than the previous splash system. Looking up trochoidal in the dictionary doesn’t help much, but it appears to be more or less a five-sided Wankel-type design.
The tensioner on the rather long chain driving the single overhead camshaft had also been altered, as the previous roller-wheel design had often been over-tightened by inexperienced types, leading to disastrous endings. Now there was a simple slipper-type adjuster, easier for the casual wrench-wielder to do properly. However, a recall in April of 1975 was due to malfunctioning slippers, and dealers would install a new version, which worked well.
Adjusting clearances on the four valves was simplified by using setscrews at the tips of the rocker arms secured by old-fashioned locknuts.
Major change was in the two carburetors—instead of the previous slide types, the new ones were of the constant-vacuum variety—and test riders complained about them being too sensitive. The throttle now had twin push-me/pull-you cables, but at slow speeds the carbs were blamed for the lack of smoothness. The rubber blocks in the rear hub, which were intended to ease tension on the chain final drive, were considered by some a bit too soft, contributing to jerkiness.
Straight-cut gears went from the crankshaft to the transmission, which now had a sixth gear. A number of riders felt the extra gear was unnecessary, as too many gears can be as frustrating as too few. Ride reviews found some testers complaining that the gears were now too closely spaced; others said the spacing was perfect. You can’t please all the people all of the time.
The most important change was the new tubular frame, with a single downtube, splitting off to create a cradle under the engine. Of note was the improved quality of the welds in the frame; their aesthetics were a couple of notches above what people had been used to seeing from Honda. Some ride reports said that, when ridden hard, the 360 tended to flex a bit more than was pleasurable; others lauded the “superb chassis.”
CL sales not being up to expectations, it was dropped from the line after two years, while a CB/T model, with minor cosmetic changes from the previous G, continued on in ’75 and ’76. Then Honda decided to retrograde the bike, coming out with the CJ360 model, which had no electric starter, drum brakes fore and aft and a 5-speed transmission. The two-into-two exhaust was changed to a less costly two-into-one running out the right side, and the centerstand was deleted. And the price lowered.
But that was just a stopgap until the CB400 appeared in ’78, the parallel twin bored out yet again, this time to 395cc, and sporting a new three-valve, OHC head, with a pair of counterbalancers to quell the vibes—and a 5-speed transmission. Maybe that sixth gear was not