The Service Department
THE SERVICE DEPARTMENT
GARY BRAY
THAT DRAG PROBLEM AGAIN
I bought a ’62 Puch SGS a short while ago with 5000 miles on it; it now has 7500. The problem is this. Every time I try to shift the gears they grind. You have to hold the clutch in for quite a while before you shift and then barely snug them in to keep them in the case. I'm sure the trouble is that the clutch isn't disengaging completely, as it tends to creep slightly while in low gear with the clutch lever in.
It had 90-weight gear lube in the transmission when I got it and I changed to non-detergent Valvoline #40. This didn’t help. I have adjusted the clutch to get the greatest release action possible without the clutch slipping while underway. Still no soap. Any suggestions on how to fix the beast?
Val Crow Logan, Utah
With many multi-disc clutches of this type, proper spring pressure and clutch trueness is achieved through a series of adjusting screws found in the clutch pressure plate. If one or more of these screws are improperly adjusted or backed out a few turns, the clutch plates do not run true, thereby causing drag.
On your Puch these adjustment screws are accessible by removing the small inspection cover on the clutch case. They should appear to have been worn-in equally. To achieve a more accurate setting, remove the clutch cover. Then the plates can be observed for high and low spots as the clutch is revolved in a disengaged condition. A high spot in the plate assembly would indicate lack of spring pressure, a low spot too much spring pressure.
If this procedure is carried out and does not altogether remedy the situation, the clutch plates should then be removed and thoroughly cleaned in solvent. The chain wheel and center hub of the clutch should also be cleaned of any sludge or foreign matter.
Then, inspect everything carefully. The fiber lined plates should not have any broken or torn places in them, or give the appearance of having been extremely hot. Next, check the plain steel plates on a flat surface, such as a piece of glass, to be sure they are not warped. Finally, if there is any doubt as to the condition of the plates, particularly the steel ones, replace them.
IT LEAKS
I’ve several problems in need of answers. First, on my 500cc unit construction Triumph, oil leaks out of the primary chaincase cover and all the fill and drain plugs. Would you suggest neoprene gaskets on the plugs, or do you know of a more effective solution? Also, where can I obtain good gaskets? (I’ve lost faith in Triumph’s fiber gaskets.) And, on the primary chaincase, should I use Permatex or some similar gasket paste? Finally, where can 1 obtain an electric or mechanical tachometer for my Greeves 250 Hawkstone?
Jim Ranson
Chicago, Illinois
Neoprene seals on filler caps do a better job of sealing and the cap is not as likely to be lost due to vibration. With drain and oil level plugs, a small amount of 3-M weather stripping adhesive smeared on the threads should stop any oil seepage.
I feel that an additional breather should be installed, either in the primary or transmission filler cap. An extra breather at one of these points may help reduce the accumulation of oil around the primary and gearbox joints. This can be done by drilling and tapping the filler cap for a Vsinch automotive fitting. The fitting can be screwed into the cap using a rubber “O” ring to seal it. With a length of plastic or rubber tubing attached to the fitting, it can then be routed somewhere out of the way on the machine.
Though I have had no problem with the factory gaskets, I do recommend using a non-drying gasket sealer. When installing primary or transmission gaskets, problems can usually be avoided if the gasket is thoroughly soaked in warm water. Gaskets that lie around for any length of time tend to shrink slightly and become rather hard.
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Nicholson Motors, 11629 Vanowen St., North Hollywood. California, should be able to fill your request for a tach.
YES, IT’S IMPORTANT, BUT . . .
I recently purchased a 1964 Super Hawk CB-77. / ran this cycle for 3800 miles to wear in the new parts. 1 then disassembled the engine to have the cylinder head modified. This work, which included a new set of cams, rocker arms, heavy-duty valve springs, bigger valves, and porting and polishing, cost me a little over $200.
I went to Honda of Boston to purchase a gasket set to assemble the engine. 1 told the parts salesman that I wanted a complete gasket set for my CB-77 Super Hawk. 1 assembled the engine, taking all necessary precautions and followed the maintenance manual.
1 started the engine and ran it for no longer than five minutes when 1 discovered an oil leak at the bottom cylinder gasket. When l disassembled the engine, 1 learned that the gasket, an incorrect part, was leaking because it was blocking the flow of oil from the crankcase to the cylinder head. Two hundred dollars cash, not to mention my time and the labor involved, was lost because of a negligent parts man who, although fully aware that there were two gaskets with two different oil line patterns, failed to mention this to me at any time.
I purchased a $10 manual for the Super Hawk when I bought the bike. When 1 disassembled the cycle, 1 checked the manual. There was no mention of the two different gaskets in this book. How is one to know? Something this important should certainly be made known to all who now and in the future intend to do work on their Hondas. This cost me $200 of my hard-earned money. 1 feel that the least that can be done is to inform the everyday fellow, who doesn’t happen to live near a Honda dealer who cared about customer satisfaction, of such an important detail.
Kenneth Benoit
Woburn, Mass.
If the motorcycle industry continues to grow as it has since the introduction of Japanese machines to the world market, this particular problem will probably get worse before there is sufficient relief. As things now stand, there is not an overabundance of experienced parts men, or mechanics for that matter.
A manufacturer produces, let’s say, six different models. Of these six, two may undergo a small modification after 1000 or so units have been sold; this frequently happens. The manufacturer notifies the distributor (or dealers) of the changes to appear on later models, but somewhere in all this leaping around there is a time lag. Who suffers? You, me and the guy down the street who owns one of the darn things too.
If you really want to understand some of the troubles a parts man has, try figuring out some of those parts books. If the machine has been in production any length of time and there are many models to contend with, the poor guy will have parts books the whole length of the counter, with superceded numbers yet. The newer manufacturers haven’t quite reached this point, but it won’t be long.
A similar problem existed in the automotive industry but they figured a way around it. Try to buy parts for your fairly late model car and some clown will tell you, “Gee. they don’t make that anymore.” If you ask, “But the car’s only four years old. What am I going to do?” he will reply, “Well, you can always buy a new car, fella.”
As long as a large and varied number of machines and models are produced, problems such as the one you experienced will occur. But there is a way to trap the poor unsuspecting parts man. Next time you need a part, take the old one along and make sure the replacement is identical before you leave the store. You’d be surprised how effective this method is.
MODIFIED SINGLE
1 am presently riding a 1954 500cc BSA single, modified with a Gold Star head and barrel. Recently 1 gave the engine a top overhaul and replaced the standard piston with a piston of 9:1 compression ratio.
In order to gain maximum advantage from this higher compression 1 am wondering if the ignition or cam timing should he altered, and if so, in what direction? Also, I have heard that a high compression piston can he run on a leaner fuel mixture. Is this true?
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Bruce Ewoldt
White Sands Missile Range, N.M.
For an increase in overall performance of your machine I most certainly would change the cams. Use a #65-2444 or #652442 inlet cam and a #65-2446 exhaust cam. Your timing should be as follows: INLET CAM
65-2444 Opens B.T.D.C.
60°
Closes B.B.D.C.
85°
65-2442 Opens B.T.D.C.
65°
Closes B.B.D.C.
85°
EXHAUST CAM
Opens before B.D.C.
80°
Closes after T.D.C.
55°
For best results with this arrangement. I recommend using a l;ijc, Monobloc carburetor. Preliminary carburetor settings should be as follows: #3 slide, 1065 needle jet, needle position 2 notch, and a .350main jet. Ignition timing should be 38° to 41° or ”j<; to ’/2-inch before top dead center with the magneto fully advanced. An increase in compression usually necessitates a richer jet.
The rule may not apply if there has been a change of cylinder heads or if changes have been made to ports and combustion chamber in the existing head. Work on the ports or even a valve job may change the
amount a cylinder head will flow. Sometimes I think there is witchcraft involved.
WHY DIFFERENT CLUTCHES?
What are the reasons for the genera! differences in dutch type between cars and motorcycles (single-plate dry dutches in cars, multi-disc wet dutches in motorcycles)? / have not been able to find any article on drive trains that answers this fairly important question.
Larry Fafarman
Los Angeles, Calif.
The biggest factor responsible for such a difference in clutch design is room. In order to achieve any clutch area and yet keep the overall size of the unit down, the multi-disc clutch has been employed. Machines such as the BMW use an automotive-type single disc clutch, but here we have a completely different engine design. Where the engine design is such that the crankshaft is allowed to assume an in-line position, room is found to use the single-plate clutch.
Concerning the question of why the majority of multi-disc clutches are wet, there are usually five driven or lined plates and six driving or plain clutch plates. When disengaged, these plates run close together and tend to create heat, hence the oil to cool them. A dry clutch, with cork inserts, was used on Ariel machines and proved quite satisfactory, providing the clutch was not disengaged for too long or excessively slipped. Another type of dry multi-disc clutch was found on early BSA twins, but here again heat was the problem. Although the lined plate which used heat-resistant material stood up, the plain or driving plates would warp, causing drag.
A LITTLE ELABORATION
In your September issue, Nicholas Porter wanted to know which of the road bikes was the biggest, fastest, best handling and most dependable. At the end of your reply you mentioned that you “sure wish they would bring back the Matchless G-50.” Would you elaborate on this?
Thomas E. Hopkins Marion, Ohio
Reference to the G-50 was intended as a comparison. It has the smallest displacement of the machines mentioned, yet is extremely fast and handles quite well. At the same time, it lacks the feel and sound of a large displacement twin that many people find most pleasing, particularly for long, high speed touring.
No one machine on the market today combines all the features that appeal to everyone. The individual must use his own judgment in choosing a machine for himself. To make a list of all the machines manufactured and circle one, saying, “Here, this is the one you want, because it’s the fastest,” would be totally wrong.
Our road tests are a guide, yet in the end a person must choose what he likes and what he feels will best fill his needs. As for the Matchless G-50, BSA Clubman and machines of that type, too bad they’ve been discontinued, but that’s progress. (?) •
