1986 Husqvarna 510
1986 HUSQVARNA 510
CYCLE WORLD TEST
A THIRD-GENERATION FOUR-STROKE GETS SERIOUS
ANYONE SHOPPING FOR A SU per-serious, lightweight, four-stroke off-road Single soon learns there are just four: ATK's exotic, extremely limited-production racer, and three versions of Husqvarna's 510-the 510 enduro, the 510 motocross, and the bike you see here, the 510 Cross Country.
That shopper also will undoubt edly learn that Husky's 510-series four-strokes have suffered their share of problems during the two years of their existence. But that information is quickly becoming ancient history due to continual updating that seems to have rid the engine of its gremlins. And with what Husqvarna calls the Third Generation Four-Stroke, that evolution continues for 1986.
Despite having a new name, though. the `86 510 engine isn't to tally new. It's the same basic motor (which consists of a bottom-end that's much like those on Husky two-
strokes, but with a sohc, four-valve, four-stroke top-end grafted on) up dated with numerous new compo nents. The cylinder head now has an offset intake-manifold flange so the new Dell'Orto carburetor will clear the single-shock frame's backbone; revised porting improves high-rpm power, but at the expense of some low-speed lugging: and new valve guides are pinned so they won't move around in the head.
Husky's unique. pumpless oiling system has been improved, too. Oil is still stored in the clutch side of the engine, carried to the cam and rocker arms by the cam chain, sucked into the engine's lower end via three holes in the side of the cylinder bore, then returned to the clutch cavity through a single-petal reed valve. This sys tem, surprisingly, supplies adequate oil to all of the necessary engine parts: but in previous years, extended high-speed running sometimes re sulted in excessive oil accumulating in the crankcase. So for `86, the reed has been raised slightly to eliminate the problem.
Clutch hassles also have plagued previous 510s, but the new bike has metallic drive-plates in its clutch which seem to be bulletproof. We slipped and abused the clutch but it never misbehaved or made any funny noises. The clutch pull is easy and smooth, too, thanks to a new cam profile on the actuating arm.
All of these improvements are ap preciated, but the change we enjoyed the most was a new balance factor for the crankshaft assembly. The numb ing vibration that marked previous 5 10 Huskys has been toned down to a pleasing rumble. Extended stretches of smooth fireroad are no longer a thing to avoid. The engine doesn't run as smoothly as most Japanese four-stroke Singles, but the vibration is not objectional.
Al! bi~ four-stroke Singles can be a bear to start on occasion, and Hus ky's 510 thumpers have been more cantankerous than most. Husqvarna spokesmen claim that the engine changes for 1986 have cured those starting problems as long as the proper procedure is followed. But we found that statment to be a halftruth. When cold, the engine can usually be prodded into life with one to five kicks, but starting a hot 510 can be frustrating and tiring. Some times the engine will fire up in one good prod, sometimes it takes as many as 20 kicks. And when the en gine doesn't start right up, you swear something is wrong, because there is no kickback or pop or any indication that the engine is even trying to run. Then, suddenly, it will come to life with one kick.
Once you get it running, the 510 can be a truly satisfying bike to ride. The single-shock chassis is virtually identical to those used on the corn pa ny's two-stroke motocross and cross-
country models, and it also gives the rider the same secure, go-anyplaceat-any-speed confidence that Huskys are famous for. The Ohlins shock is perfectly damped (when both the compression and the rebound adjust ers are in the center of their adjust ment range) and the shock's spring rate is right on the money. The Husqvarna-built fork is quite good, as well, but it doesn't match the rear shock for excellence. The fork has good damping control but the springs are a little soft, which causes a lot of front-end wandering in sand. On harder ground, there's much better stability. Replacing the standard 19pound fork springs with a set of 21pound springs should cure any front end complaints.
Despite the soft front springing. the steering precision is surprisingly good. Staying on the trail at break neck speeds is easy, for the bike reacts instantly to steering input but yet does not steer too quickly. -
There are a few surprises in the front brake, too. Traditionally, the front stoppers on European bikes re quire a lot of muscle to operate. but that is not the case with the new Husky thumper. The brake disc from last year's two-stroke Huskys has been combined with a new master cylinder, and the result is that haul ing the 5 10 down to a stop is an easy, two-finger operation. In addition, the lever is an easy reach with normal sized hands, and there's even an ad justable lever throw.
Rear-brake action also is greatly improved compared with past mod els. A new backing plate that fits in side the hub more snugly helps keep water out, and the torque arm has been eliminated in favor of a tonguein-groove arrangement between the backing plate and swingarm. An alu minum brake pedal with a steel-claw boot pad provides good leverage, and an exposed cable between the pedal and the high-mounted brake arm al lows good braking feel. An external return spring keeps the rear shoes from sticking in muddy conditions.
One of oirr biggest gripes with last year's Husqvarna 510, an enduro model, was the extreme width of the bike in the area just above the footpegs. But the `86 four-stroke is much thinner through the middle, thinner, even, than a two-stroke Husky. That's due to the single-shock chassis, an airbox that is tucked in better than those on the two-strokes, and a slim, 2.4-gallon gas tank. The side-mount airbox draws its air from under the seat and shouldn't ingest water as long as the rider doesn't ford rivers that are higher than the base of the seat. For some reason, though, the standard air-filter element is pa per, which can completely stop the flow of air if it gets wet; that's why Husqvarna replaced our test bike's filter with a K&N oiled-gauze ele ment before giving us the machine.
Another c~mpIaint, one that'll be harder to fix, is a tendency for the engine to ping just off idle when rid den hard. Using leaded premium gas and some octane booster helps but doesn't completely cure the problem. Lowering the compression ratio by using two base gaskets might elimi nate the pinging, or perhaps some ex perimentation with different carbu retor jets or slides might be the answer; but we didn't have the oppor tunity to do either, so we can't say for sure that either would work.
Despite its several shortcomings, however, the 5 10 is an excellent all around off-road thumper, although it seems most at home in wide-open surroundings, such as in the desert. The six-speed transmission allows for blistering top speeds, and you have to encounter a really steep, long hill be-
fore you actually need to use low gear. The seat is firm but comfortable, mostly because it has an excellent shape. The seat is 38.3 inches high, though, which makes dabbing diffi cult for all but the tallest riders in tight or rocky terrain; but in open country, this isn't a problem. Reduc ing the rear-suspension travel an inch or so would fix that problem while still leaving about 13 inches of travel, which would be more than enough for the vast majority of the use the 510 will see.
If the bike spends much time on hard terrain, its rider will appreciate the Metzeler tires that, for the first time, are original equipment on all `86 Husqvarnas. Soft, comfortable grips also are standard, and the tank decals are recessed so they don't get rubbed off.
In addition, maintenance chores on the single-shock rear suspension's linkage has been simplified. Grease fittings on all of the pivot points turn what was a day-long lube job into a few minutes' easy work. But some things never change. and the ex tremely troublesome kill button that's been causing problems on Hus kys since 1 967 is still around.
So as you can see, Husqvarna's four-stroke Single, now in its third year of production, still has its flaws. But Husky finally seems to have got ten the big things right, and the result is a dead-serious thumper that can have most of its shortcomings reme died without too much work. The pinging undoubtedly can be fixed, the fork springs can easily be re placed. And right out of the shipping crate, the 510 is light (257 pounds without gas) and doesn't have a top heavy feel like other four-stroke Sin gles; and it'll outrun and out-handle anything Japan currently offers.
No, it isn't perfect as it is: but until something better comes along, it's the closest thing to four-stroke off road perfection that the average per son can buy.
1986 HUSQVARNA 510
Husqvarna Motor Co, Inc.
