The bike starts very easily thanks to the automatic decompression device, but lighting the 150 might be a little harder for a smaller rider because the kick swing is longer and starts higher than the 85. Then the bike purrs right into a high idle. It snaps to life with any crack of the throttle and revs with a ferocious quickness and a mean exhaust tone to match. This is not a playbike by any means, beginning with the sound, which is very similar to a 250F. It takes a little throttle to get going, and as with an 85cc two-stroke, you need decent clutch control. First gear, on both small-wheeled and large-wheeled bikes, is plenty low, and you'll likely never use it on a track. The bike pulls smoothly and linearly from the bottom-which seems to start at about 6000 rpm-all the way to a 14,300 redline. Interestingly enough, the bike makes its peak power at 12,500. According to one of the engineers on hand, the 150 was tuned that way for safety. It will teach kids to shift instead of letting the bike sit on the rev-limiter. Even past peak power, there is pull, but there is plenty of warning that the best method for speed is an upshift to keep the little motor in the meat. Concealed in the cases are some new tricks for the CRF line. The tiny piston has a very intricate dome build that squishes the fuel-air mixture into a tidy 11.7:1 compression ratio in the very oversquare 66.0mm by 43.7mm bore and stroke. The Unicam operates four steel valves (26mm intakes, 22.5mm exhaust); in Honda-speak, because they are so small and thus are already light, there's no need for titanium. In the real world, Honda knows that Dad is not expecting to rebuild this head every year for Junior; the steel valves will last longer (and cost less). There is an extra lobe on the cam compared with the bigger CRFs because now there are two exhaust rockers instead of the one forked arm of the bigger engines. Less room inside the head and the combustion chamber while still using the same size of spark plug as the big CRFs mandates this new design.
But the question is, Is it fast? For a bike in the 85cc class, the answer is yes. It makes a little more peak power, and it definitely has a longer power pull in each gear. There is strong torque coming out of this powerplant, but it comes with rpm, not by heavy weights and long piston strokes helping to keep things spinning. The pull close to idle is similar to a small two-stroke, and the bike will bog just the same if it isn't wound up. It hauled around this 180-pound rider just fine, and all I saw from the kids riding the bike was their astonishment at the power.
The clutch was typical Honda excellence, and shifting was just as good. The gear ratios were tight in the five-speed gearbox, with second through fourth taking turns on a typical track. Fifth comes into play on long straights, but first will take the tightest turn to get a call. There is very little compression braking, and the stoppers on this bike give great feel and are not too grabby for younger or less experienced riders. Fast or heavy guys could use a little more.