Bultaco's 352 Jim Pomeroy Replica
BULTACO'S 352 JIM POMEROY REPLICA
Cycle World Road Test
Look Out DeCoster, Here Comes John Q. Public.
First it was the horsepower race. Everywhere you looked in motorcycle-related brochures or publications, there they were—the Orientals and the Europeans—all trying to out horsepower one another from the advertising desk rather than from the dyno room. And, as much as we like Bultacos, we must admit that they haven't been the most innocent in this respect. In fact, they got so bad at it that several people began referring to Spanish hp ratings (Montesa was also culpable, as was Ossa, although to a lesser extent) as ponies rather than horses.
Then, the government said that if you're going to print hp figures, you'd better be ready to back them up. Most of the factories stopped releasing such info soon after this decree, but little by little they've begun releasing more realistic figures. A manufacturer is no longer ashamed to admit that his 250 MX can't even reach, let alone break, the 30 hp figure, because he knows that no one else's 250 MX can do it either.
The introduction of the Honda Elsinore series brought buyer attention around to another crucially important aspect of motocross bikes—weight. The Hondas were advertised as light, very light, and they were. If you know where to look for such things, you may have noticed that everybody else’s bikes were suddenly getting lighter and lighter, as well, and in the middle of a production year! Well, at least the ads said they were lighter.
In the middle of 1973 and in early ’74, some truly light machines have seen their way to dealers’ showrooms. The YZ Yamahas, the Husqvarna 250CR (a magnesium and chrome moly rocketship that we tested last month), and the Montesa 250 VR, for example. Both the 250 and 450 Kawasakis weighed in at under 220 lb. dry. But now comes the kicker. Guess who’s getting in on the weight race, but on more legitimate footing this time around“1 That’s right, friends, Bultaco.
And guess what the new 360 Pursang Mark VII (alias the 352 Jim Pomeroy Replica) weighs? Wrong. Wrong again. How about 204.5 lb. with a dry fuel tank? “But that’s under the FIM weight limit (209 lb. for 500cc class) motocross,” you say? You’re right, but that isn’t going to keep Bultaco from selling every last one of these trophy-hoarding featherweights. You see, while it may be illegal for FIM (and, consequently, FIM-approved AMA) motocrosses, how many of you are going to buy one to ride in those races? We thought so.
Most of you will end up in the beginner; less-than-five-races; left-handed; blister-on-your-big-toe class, in which they don’t care whether your knobbied Honda 300 Dream weighs two pounds or two tons. However, those of you who are sure that this year you’re going to be banging berms with Pomeroy, DeCoster, Weil and company, should take heart. First, while not perfect, this bike is capable of accomplishing the aforementioned if you are. And second, adding weight to this machine is as easy as adding something minor—like a skid plate.
Although a totally new machine for Bultaco, the Pursang does utilize some components from the 326 Pursang ifet it replaces. Inside the same basic crankcase castings as Wore, you’ll find crankshaft flywheels that are wider and larger in diameter than those of the 326. The connecting rod rides on roller bearings at the crankpin, and on needles at the wristpin.
The piston, at 83.7mm, is only 0.5mm larger than the one on the 326. The increase in displacement came from stretching the stroke 4mm...out to 64mm. Because of the crankshaft’s extra width, there is only one ball bearing on each side instead of two. This arrangement has proven satisfactory in International GP racing, so you worry warts don’t have to sweat over losing the lower end.
Inside the cylinder there are dual transfer ports on each side that are angled differently from each other (on the same side) to assure proper and more efficient cylinder filling. The cylinder head features a deep trench area; and two spark plugs, firing at the same time, ensure complete fuel combustion. The plug at the front of the engine is one heat range colder than the one at the rear, because the rear one is cooled more by the incoming fuel/air charge, and the rear of the cylinde^uns cooler anyway.
Starting the “Poosang” is easy, even when cold. Simply flood the 36mm Amal carburetor with the tickler while holding the throttle open to insure a raw fuel charge into the intake tract. Then swing out the left-side kickstart lever (it really should be mounted on the right, but then it wouldn’t be a Bultaco unless it gave us some reason to gripe), and give it a couple of healthy tromps. Once the engine fires, the throttle must be blipped for a few seconds, since there is no choke mechanism. If the machine is already warm, open the petcock and kick away. It should fire after two or three tries. The only time we had trouble starting the machine was after a minor spill. It was impossible to kickstart it, so we pushed. And pushed. It finally lit. The trick here is, don’t fall down. >
The Bui’s engine is misleading at first. It has neither the over-carbureted lumpy idle of the Husqvarna CR, nor the eye-enlarging super-zippy revs of a Honda Elsinore. It responds like a slightly modified enduro engine. But all of this blandness disappears once you snick the live-speed gearbox into low. The 360 takes off with the authority that only a 500-class machine can possess. At first you might think that the all-steel-plate clutch is slipping as you shift through the gears, but if you turn around, you’ll notice that the 4.50 x 18 Pirelli has been spewing a roostertail of surprising proportions.
The transmission that delivers the engine’s output to the rear wheel is operated from the right side with a down-tor-low pattern. Gear selection demands a positive motion. The transmission won’t “slip” from one gear to the next, but it shifts. You can almost feel the coggery moving around every time you change ratios. Missed gears were usually the fault of the rider, although once or twice we would have liked to blame the machine. We did have one failure with the bike though.
While testing, Editor Bob Atkinson flew into a high-speed sweeper as he had done many times before on this Bui. But, in the distance between this corner and the previous one, a cotter pin, which holds the brake rod onto the hooked end of the brake actuating arm, had come oft. And so had the brake rod.
The resulting crash and string of military curses left us all thoroughly amused. This morning we noted that the last of the haybale straw seems to have found its way out of Bob’s coiffure, that his pupils are slowly returning back to a normal size, and that the muscles around his jawbone are starting to loosen up. We also noted that the Bultaco had had its faulty cotter pin replaced with safety wire—about eight feet of it. Once was obviously enough!
Apart from that one malfunction-related wipe out^ü was easy to stay astride the Pursang, regardless of the terraii^
This motorcycle does not have the plush suspension found on a Maico, but it does work well. We found the Betor forks to be slightly over-sprung for riders under 175 lb.; likewise the rear shocks. It feels as though the suspension has not yet been adequately tuned to the machine’s decreased heft. Regardless of the comfort of the ride, the Bui absorbed bumps well, although the rear wheel would occasionally kick around in the real nasty stuff.
With a heavier rider, the suspension was working better, and could even be made to compress fully on occasion. This should be avoided, however, as the front wheel will rub against the fender when the front end is collapsed. It won’t lock the wheel up unless the fender is clogged with mud. If it is, you’re going to get off.
The fenders should be changed anyway. They are the same brittle fiberglass items that came on some of the first Pursangs. While they do have some give, the first time they get banged up seriously, they’ll break—if the vibration doesn’t crack them first.
We never noticed any rear-wheel hop under braking; and the brakes, when they work, are strong. The front unit, a half-width affair made of Dural, offers much more feedback to the rider than the rear binder. This is not to say that the rear brake is insensitive, but you can’t really be sure exactly what’s happening back there by what the left pedal tells you. Perhaps with time a rider can become accustomed to the brake and develop a feel for it. The actual brake, a two-piece half-width anchor, also made of Dural, is new to this year’s Pursang. It’s ven^^ht.
3^rdng position on the Pursang is up from last year, and a new seat and redesigned fender have been added. The devilish Bultaco hump is gone. Although a bit tall for our shortest staffer, the position of the seat makes for very comfortable sitting-to-standing transitions. And vice versa.
The “water pipe” frame is also a thing of the past. All Pursang models for ’74 come with a chrome moly frame. The steering geometry is the same as the Pursang Mark VI. The berm-hunting Bultaco is history now. This geometry allows a rider to select a line and stay on it through a turn. You won’t be able to slide under a tight-turning Maico, but you’ll cut circles inside and around drifting Elsinores. It is about as neutral-handling as any bike there is. You can make it slide, if you wish, or track it around at an increased angle of lean.
This is the 352 Pomeroy Replica for 1974. The chrome moly frame and handlebars, Dural hubs and light, and non-lipped Akront rims make it almost absurdly light. And, it can be made even lighter. It is as good-handling as Bultacos have always been. It even has good brakes.
Jfe? Pursang possesses plenty of power, although the 450 Mai^ (a pre-established class nemesis), pulled eight more horses on the dyno. However, the Maico engine has 76cc more piston displacement. There may be a few tracks where the difference in power will make a difference, but one thing’s for sure: At its present weight, the Bultaco 360 Pursang Mark VII won’t beat you to death out on the track. Neither will the price. El
BULTACO 352
SPE:CIFICATIONS
$1395
POWER TRANSMISSION
DIMENSIONS
DVNAMOMETER TEST HORSEPOWER AND TORQUE
