The Service Department
THE SERVICE DEPARTMENT
GARY BRAY
SHAFT WOBBLE
I have a 1960 BSA Super Rocket. I plan on having the casings of my transmission chromed. In chroming, as you know, a certain amount of chromium is deposited in the casting. What I would like to know is will this cause end wobble in the shafts due to the added metal on the facings of the casting?
Also 1 have heard rumors that plating can lead to a leaky transmission due to an inadequate bond. Is this true?
Dennis B. Worth Chicago, Illinois
Plating in and around the bearing bosses should cause no appreciable transmission shaft runout. However, plating in this area should be avoided if at all possible. Addition of metal to the inside diameter of the bearing boss may create extreme loading of the bearing. The result could be complete bearing failure or premature wear. If possible, a set of old bearings and bushings should be left in the cases when the plating is done.
Transmission housing joints should not be affected by plating as gaskets are used throughout the BSA gearbox. Leakage sometimes occurs in transmissions which depend on a metal-tometal seal. A non-hardening gasket sealer and hand lapping will usually remedy any possibility of leakage. Wherever plating may affect a bearing or bushing housing, steps should be taken to eliminate any metal being deposited in them.
HOW'S THAT AGAIN?
1 recently purchased a set of S & W oil pressure and ammeter gauges for my 1965 250cc Villier s MK 32 A/4 track and sports engine. 1 know how to install the ammeter gauge but where do 1 hook up the oil pressure gauge?
Thomas R. Kelly Closter, New Jersey
The two-stroke powerplant does not utilize a pressure lubrication system. Lubrication of this type of power unit is by a fuel/oil mixture which lubricates as it moves through the lower end and into the combustion chamber via the transfer ports. Movement of this mixture is created by action of the piston and flywheel assembly. Since there is not an independent oil pump to supply oil at a given pressure through the crankshaft (as is the case with four-cycle engines), installation of an oil pressure gauge on a two-stroke is not feasible.
Some two-cycle machines do employ a metering device which introduces the oil supply into the crankcase. This system does away with the necessity of mixing gas and oil together before filling the gas tank. However, lubrication is still accomplished by oil mist being pulled through the engine.
WILL A LITTLE BIT GO A LONG WAY?
I would like to know, if cruising speeds are maintained, could the Honda Super 90 and CB-160 make long trips?
Homer Blackburn Ypsilanti, Michigan
There have been instances of small displacement machines making coast to coast trips without major mechanical mishap. Naturally, the smaller machine’s cruising speed will not be as high as many larger displacement motorcycles and automobiles. Maintaining reasonable speeds which do not overburden a powerplant is simply self discipline on the rider’s part. You’ll probably catch those cars when the road gets twisty anyhow.
Also, the lower speeds at which the smaller machine must be operated over prolonged periods allows the rider to absorb the beauty of the countryside and other scenic wonders. Well, at least whatever countryside is visible between the billboards.
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FRUSTRATION
The rocker box on my 650cc BSA does not respond to treatment. It leaks oil in spite of various types of gasket material and sealers. Breathers have also been installed in the rocker box inspection covers. This problem exists, to a lesser degree, at other points on the engine. What do you think of cork as a gasket material? Is there a better gasket material I can use?
Philadelphia, Pa.
Paul Bogdanoff
Severe oil leakage at engine gasket joints can mean worn rings (which increase crankcase pressure) or a plugged or blocked crankcase breather. However, BSA twins do suffer gasket trouble at the rocker box and cylinder head joint. This problem is more acute with the alloy head model. The alloy head has five bronze inserts in the cylinder head which the main rocker box bolts screw into.
With the passage of time and machine operation, these bronze inserts tend to pull outward slightly. When this condition exists, an uneven gasket surface prevents proper sealing. These areas can be carefully dressed flat with a file if the surface is not too badly distorted. The most satisfactory method of dealing with this problem is to resurface the offending gasket areas.
While the iron head does not suffer as greatly from distortion as the alloy type, it certainly should be resurfaced if there is any doubt about condition of the gasket faces. Another point where the same form of trouble may be found is the sump plate. By using a thicker gasket, or doubling up the standard gaskets, a seal may be obtained. Since a Vx 20 thread is used for the sump plate studs, heli-coils can be installed. This usually stops further distortion around the bolt holes.
Cork is not suitable for gasket material where extreme pressure and heat are encountered. With the gasket surfaces in good condition the standard paper gasket should perform satisfactorily. If for one reason or another the gasket surfaces cannot be remachined, and the making of special gaskets is contemplated, soft copper .010 to .015" thick might do the trick. I won’t guarantee this will stop the oil leak, but it may slow it to some degree.
NO RESPONSE FROM A SPRINT
1 have a 1962 Sprint C, and it just will not start. 1 have checked the coil, battery, spark plug, points and fuses. What do you think the matter can be? The type of spark plug used is a Champion #7. Could this plug be of the wrong heat range for operation in the Maryland area?
Frederick Bahr Baltimore, Maryland
When a machine fails to start, a process of elimination must be followed to determine the cause. From the components already checked it seems there was some doubt as to the efficiency of the ignition system. First it must be determined if the ignition system is creating the difficulty.
If engine compression is good and the machine had been operating in a normal manner, a serious mechanical problem can probably be ruled out. There is a chance the fuel supply has become contaminated with water though it is unlikely that this would keep the powerplant from at least showing some signs of life. If this is suspected, drain the tank and refill with fresh gas.
A simple method for determining the presence of spark is to remove the plug and place it against the cylinder or cylinder head. The ignition points should be in a closed position and the switch “on.” Separating the ignition points slightly with a small screwdriver should produce a spark between the spark plug electrodes. If no fire is evident, try the same test using a new spark plug (plug testers are not always reliable). A sudden appearance of spark with the new plug means you’ve suffered plug failure.
If, even with the new plug, there is no spark or at best a very weak one, reddish in color, two areas not previously checked are now suspect. A weak spark that is poor in color (it should be blue white) indicates a faulty condenser. Complete lack of activity from the spark plug also points to condenser trouble or a malfunction somewhere in the power supply. The weakest link in this system is the ignition switch. This type of switch is similar in construction to a set of ignition points. When the ignition key is pushed down, a spring steel blade is forced into contact with a fixed tab mounted on the switch panel and the ignition circuit is completed.
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Occasionally this tab becomes bent from pressure exerted against it, and an incomplete circuit is the result. After carefully examining the tab and related parts of the ignition switch for physical damage, the tab can be rebent into its original position and the contact points cleaned with light emery paper. Evidence of fractures at the base of the fixed tab, however, will mean replacement of the ignition switch. Although the switch may be the trouble source, the possibility of a broken wire or poor connection must not be overlooked. The heat range of the spark plug you are presently using is quite satisfactory.
BAD BEARINGS
/ own a 1964 Triumph TR6 on which the main bearings went out at 12,000 miles. My partner has a 1964 Bonneville on which the main bearings went out at 15,-
000 miles. We have talked to numerous other unit construction 650cc Triumph owners who have encountered the same problem. Could you give us any information as to why this is an apparent problem in the unit construction engines and if so, could you tell us how to keep this from recurring.
Roger Q. McFarland
Inglewood, California
The basic design of the unit Triumph does not differ much from previous models. A lot of changes have been made to strengthen the power unit, if anything. Engine design is not the problem. Dealers
1 have talked with maintain this has not been a source of trouble.
In the one new machine that I know of which had bearing failure, the main bearings were found in a rusty condition. Before assembly at the factory the bearings may have been exposed to moisture or some foreign matter. Such conditions would certainly shorten their life. Although an uncommon circumstance, it is a possibility.
After new machines are set up by the dealer they are cleaned. Water used in such an operation poses no great problem, but use of steam cleaning equipment might. Water vapor may have found its way into the crankcase through the engine breather. Before new machines are put on the floor they are usually run; however, this is not always true and running time is at best, short. This could allow whatever water that has found its way into the lower end to damage the bearings.
In some instances a machine may have had the bearings loaded too heavily. This can occur if the diameter of the crankcase bearing boss is too small, coupled with the shaft diameter being too large where it fits through the bearing. Extreme bearing loading results in excessive wear, particularly during the engine’s warming up period. To alleviate this problem the shaft should be sanded until the bearing can be tapped in place, rather than bashed on with with a king-sized hammer.
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At times, bearing failure can only be assumed as being a faulty part. When this is the conclusion reached, a replace ment bearing of a different brand may ease the owner's mind.
QUICK
A few of us cycle enthusiasts share dif ferent opinions concerning a few motor cycles so I though II would be best to get the correct information.
What is the approximate top speed of the M.V. Agusta 500cc, the Gilera Four 500cc and the Norton Manx 500cc and why can't an individual purchase one of these machines?
What model of the old Vincent was considered the faster, the Black Shadow or the Black Lightning? 1 once read in a motorcycling magazine that the Black Lightning was clocked at around 156 mph and the Black Shadow at 128 moh.
Also, what were some of the reasons for the Vincent Company to discontinue pro ducing their fine motorcycle? John P. Mulcahy - Travis AFB, Calif.
Speeds in excess of 160 mph have been claimed by M.V. and Gilera. The Norton Manx is said to be 10 to 15 mph slower than the fours. The M.V.s and Gileras were strictly factory supported racers and only a few were ever built. However, Norton did for many years produce Manxes available to the independent rider.
The Black Lightning was the quickest of the Vincent line, but was produced only upon order. Not enough machines were sold by Vincent so they turned to more profitable fields of manufacturing.
HARDLY EVER
I have a 1964 BS4 Trail Bronc 175cc and would like to know how much trouble it would be to "drop in" a 1964 BSA 250cc Model C15 engine in this frame. Would this fit without much modification to frame and motor mounts? Would this be at least a half-way practical installation? Dan Semuhuk Tipton, California
Engine swaps of the kind ;ou desire are for the most part not practical.
Since the power plant you wish to in stall is larger, particularly in height, ex cessive alteration of the front frame section will be necessary. The chassis itself may not stand the increase in weight and power of the larger engine.
IT MUST BE SLIPPING
I recently bought a 1962 BSA Super Rocket. Sometimes when trying to start it the kickstarter gets stuck. The bike's pick up is also very poor. A lot of noise but not much go. Finding neutral and shifting gears is hard. There is quite a bit of grind ing whenever I make a gear change. What can I do about these problems? 1 also want a four gallon gas tank painted. My friends say 1 just need to sandpaper the tank and paint. What kind of sandpaper and paint should 1 use?
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Jim Kalmbach Phila., Penn.
The sticking of your kick starter is in all probability due to worn starter quadrant and gearbox mainshaft starter gears. Replacement of these components is fairly simple and only the outer transmission cover need be removed.
To carry out this repair two gears will be needed: Kick starter ratchet pinion #67-3376 and kickstarter quadrant #423163.
Grinding of the gears indicates excessive clutch drag. This, coupled with poor acceleration, which probably is due to clutch slippage, means replacement of several clutch components will be necessary.
As these clutches are rather difficult to work with, and do require a special puller to remove the unit from the transmission shaft, I suggest you have the work done by your local BSA dealer or someone familiar with this brand.
Before attempting to paint your gas tank I would certainly check with people in this line of work in your area. What appears to be a simple paint job may end up hurting the appearance of your machine considerably.
TOO HIGH
I was reading in Speed and Custom about the BSA Spitfire Hornet. And they said they got one of these cycles to turn a 12.9 quarter-mile by using a 6.17 cheater sprocket. 1 am very interested in this machine. 1 now have a 1960 BSA Super Rocket, and plan to get a Spitfire Hornet in the spring; therefore 1 would like to know what the rest of the gearing was on the BSA that turned 12.9. 1 wrote to them when the magazine first came out about the gearing and they have not written back, so l have given up in the hope that you can help me.
Bill J. Steinke St. Paul, Minn.
From the factory the BSA Flomet is fitted with a 28-tooth engine sprocket, 58tooth clutch chain wheel, 21-tooth counter shaft sprocket, and a 42 or 46-tooth rear wheel sprocket. However, some of the late BSA twins have come fitted with 23tooth counter shaft sprockets.
The stock gearing is much too high. Normal procedure has been to change the counter shaft sprocket from 21 or 23 T to a 17 or 19 T sprocket. *
