Tech Corner

Technical Q and A for classic motorcycle maintenance and repair.

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3/4/2015

Keith Fellenstein

Norton luggage rack

Q: I’m trying to find a sissy bar and luggage rack for my 1975 Norton Roadster, to no avail. It could be either of the two or a combination sissy bar/rack. It doesn’t need to carry much weight, either. The items I’d carry are an extra helmet and rain gear. Any suggestions? — Mitch Zyman/Merrick, New York

A: There are a couple of options, one of which we did an article on a couple of years ago. Here’s the link to that one. Also, check out Andover Norton’s website accessories page. Scroll down a bit and you’ll find their luggage racks. MC



2/18/2015

Keith Fellenstein

Under pressure

Q: I just bought my first Harley-Davidson, a 1979 Sportster, after years of owning Japanese bikes. Reading the OEM service manual about changing the oil, the manual mentions the possibility of “the oil pump losing prime because of trapped air” after draining the engine oil. “After 1 minute if the oil light doesn’t go out, loosen the oil pressure switch with engine running and let 2-oz drain from the threaded connection.” After speaking to a few Harley mechanics in the area, I’ve been told not to worry about it. I just hate the thought of the engine running for a minute without proper oil pressure, and loosening the oil pressure switch is a chore. Am I making too much of a deal over it? Will the air work its way out by itself? Is there an easier way to remove the air? How about a tee between the oil pressure switch and the oil pump with a petcock? — Ted Chris/Horn, Florida

A: I can’t claim much experience with Harleys, so I’d defer to the actual Harley mechanics and the service manual in this case. You’d be surprised at how little oil is needed to keep the plain bearings happy if the engine is not pulling a load, so even though a minute without oil pressure sounds bad, if you’re not revving the engine it’s probably not as bad in practice as it sounds. MC



2/11/2015

Keith Fellenstein

A stuck clutch

Q: I’ve just come back to using my Triumph Silver Jubilee after several months away and it starts just fine, but the engine lurches and stalls when I pull in the clutch and try to put it in first gear? What’s wrong? — Larry Dodd/via email

A: Your clutch plates are stuck together from sitting, and when you pull in the clutch lever to separate them, they don’t. It’s a common problem with old Triumphs, and it has an easy solution. Pull the clutch lever in and use the kickstarter like you were starting the bike. Do this a few times with the key off and the plates should free up quickly. If they don’t, do the same thing but with the key on, starting the bike with the clutch pulled in. That should break them loose if the first method fails. The long term cure is to ride more. Another thing to check if your bike has been sitting is the oil level. Often the oil will end up in the engine sump, which presents problems of its own. It usually only makes it hard to start the engine due to oil drag on the crankshaft flywheel, but in extreme cases, it can force the primary oil seal out of its seat. That’s not a problem on your bike, as the primary side isn’t a separate oil bath; it shares engine oil and ventilation with the crankcase. Once you have the bike started, it’s a good idea to open the oil filler cap and make sure you have good oil return to the tank. I usually briefly close the return pipe with my fingers to force a little oil into the rocker arms. Don’t rev the engine any more than necessary to keep it running until the return side of the oil pump has had enough time to empty out the sump. This usually takes a couple of minutes, at most. You can ride it, just don’t give it the beans until the sump clears. MC



1/28/2015

Keith Fellenstein

Shifting issues

Q: I own a Norton Atlas with a single carburetor and magneto ignition. Lately, when I shift from first gear to second, it goes into second and then as I open the throttle it jumps into neutral. When I press down on the shift lever again it will go into second gear. I should also mention that I am having some clutch issues. The lever pull is very hard and the gearbox is a bit loud when shifting gears. What should I check first? — Mike LeBlanc/Moncton, New Brunswick, Canada

A: My first guess would be worn gear dogs causing your bike to jump out of second gear, but if it stays put when you push down on the lever it may be that the shift plunger that holds the gear cam in place is not doing its job. If it has been a few years since the gearbox has been renewed, now would be a good time to pull the guts out of the gearbox and inspect all the components for wear. Gear dogs get rounded off over time, bushings wear and mainshaft and countershaft bearings wear, too. The plunger that holds the shift quadrant in place gets rounded off and doesn’t provide a positive lock between gears. Bringing the gearbox back to specifications should give you more precise and steady gear changes. MC



1/14/2015

Keith Fellenstein

Stuck bolt

Q: I have a frozen button-head Allen bolt with the socket stripped out. Can I use an extractor to try and remove it? — Curt Shontz/via email

A: I don’t like to use bolt extractors except as a last resort. There’s nothing more frustrating than having one of them break off while trying to extract a bolt, and since they’re harder than a drill bit they’re impossible to drill out. My favorite technique is to use a left-hand twist drill bit in a cordless drill set to reverse. Often the drilling heat will help extract the bolt. If it doesn’t, at least once you have the head drilled out and the pieces apart you can grab the stub of the bolt with vise grips and get it out. MC



12/31/2014

Keith Fellenstein

Wiring search

Q: Where can I find the same colored wire on my 1974 Triumph Trident without buying a whole harness? I’m looking for small spools. Also, why do I have 6-volt coils with my Boyer ignition and a 12-volt battery? — Mike Stroobants, via email

A: You can find the individual wires you need to match your harness at British Wiring. They have complete harnesses and also the individual wires in a variety of color combinations, sold by the meter. The reason you have two 6-volt coils in your ignition is the Boyer is a wasted spark ignition; it fires both coils every time one of them needs a spark. One of the cylinders will be on the compression stroke and the other will be on the exhaust stroke. That means the coils have to be in series electrically, so two 6-volt coils present the same electrical load as one 12-volt coil would in a points-fired ignition. In a points-fired ignition, each coil is wired to a set of points and each coil is charged and discharged singly, so the electrical load flips back and forth between coils as the engine runs. Another way to do this would be with a single 12-volt coil with two spark outputs. MC



12/17/2014

Keith Fellenstein

Energy transfer conversion

Q: I would like to convert my BSA C15S with the energy transfer system to a 12-volt battery/coil system, but I have no idea how to accomplish the task. Can you help me? — Bruce Riecke/via email

A: To begin, you will need a 12-volt stator. It also wouldn’t hurt to buy a new rotor, as they lose magnetism over time and won’t create as much current. You’ll also need to replace every bulb on your bike with a 12-volt equivalent. You’ll need to replace the energy transfer (ET) coils with conventional 12-volt units. If your ET coils are original equipment and in good shape, keep them someplace safe, as they are worth their weight in gold. You will need a 12-volt battery and a 12-volt rectifier, or you can use a Boyer Powerbox and continue to run without a battery. You will also need to find a 12-degree auto advance unit to replace the 6-degree ET unit. When I got my 1964 Triumph T100SC with ET ignition years ago, I wanted to upgrade to a 12-volt battery/coil but was advised against it by an old flat track racer who lives in my area. His advice was classic. “Does it work now,” he asked? “Yes,” I replied. “Then don’t mess with it.” I’m still running my ET. MC



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