Tech Questions & Answers

Got a questions? Try to stump mark Zimmerman at

Clutching at Normality
I've started the post-season maintenance on my 2001 Volusia and adjusted my clutch lever free play according to the Clymer manual. First I loosened the locknut on the clutch release adjusting screw, and turned the adjusting screw out 3 turns. I then loosened the jam nuts on the cables to allow slack in cable. I turned in the clutch release adjusting screw until resistance was felt, then backed it off 1/4 turn, per the manual. Holding the screw in position and I tightened the jam nut. Finally I adjusted the cable end jam nuts to allow for the 0.4 -0.6 inch of free play, all this times 2.

Question: I don't ever remember feeling any rolling resistance when the bike was in first gear and the clutch lever pulled in, but I do now. Maybe I just didn't notice this before. Should there be some resistance if the clutch is adjusted properly? If not, what do you suggest? The resistance is not severe but certainly more than in neutral.
Via e-mail

_What you're feeling is perfectly normal. There are two factors at work: First, even though the clutch is held in, pushing the bike turns the rear wheel and final drive, which turns the transmission output (counter) shaft, and whatever gear happens to be engaged. In turn, the output shaft will rotate the transmission input shaft, via the engaged gears, as well as the clutch hub and clutch driven plates. The only things not turning are the clutch drive plates, the clutch outer drum and the engine. All of those pieces create drag, and that's what you're feeling. Secondly, all those parts are running in engine oil, which creates a viscous drag-especially when it's cold.

_When the bike is in neutral, turning the rear wheel turns the output shaft, but because no gears are engaged, all that turns is the shaft itself and, depending on the transmission design, perhaps one fixed gear. The input shaft, the rest of the gears, and the clutch pack remain stationary, so there's very little, if any drag.__

Deep In Something
Here's one for you, Mark, I know you're a deep thinker! As we develop more powerful batteries to power (for any duration) our vehicles, will this expose the user to a high EMF field? I have heard this can be dangerous to people. I'd think in a car they could probably provide some shielding, but I'm wondering about on a bike. I think "fuel" will long be favored in many motorcycles, as the whirr of an electric motor can't compare to the burbling of a Harley engine, but I look forward to other, sustainable sources of power also.
No name
Via e-mail

I'm usually deep in something but it's rarely thought. EMF fields are associated with AC current, so that gets batteries, which can only store DC current, off the hook. The alternators that charge the batteries, even the ones we currently use (a little electrical joke there) can produce an EMF field, but not at frequencies or intensities that cause problems.

A Bigger Wrench?
I have a problem: The bolts on my Harley that hold the handlebars in place keep coming loose. How can I tighten them? I've used blue Loc-Tite, and it didn't do the job.
David Rice
Via e-mail

First, check the holes the bolts thread into, and the bolts themselves for any sign of damage. If the threaded holes are damaged or suspect in any way repair them using a Heli-coil-style threaded insert, or replace the bracket. Likewise, make sure the bolt threads are in perfect condition and that the bolts aren't "necked" or stretched leaving a thin section in the middle. If there's the slightest doubt, replace them with new bolts. Use brake clean or contact cleaner to degrease everything. Install the bolts clean and dry, and torque them according to their diameter and SAE grade.

Guzzi Gauge
I ride a Moto Guzzi California Stone, and (after my wife) she's the love of my life. Having said that, I have found room for improvement, as the Stone is, to my eyes, inadequately instrumented. I want to add cylinder-head temperature gauges, and it seems to me there should be simple gauges that clip right to the back of the cylinder head. Although I'd prefer numbers, I'll accept gauges that simply use colors. Is there such a thing, and if so, where may I obtain it? I'm reluctant to use a gauge on the 'dashboard' because there's not much room up there as is.

Last summer my wife and I rode from R.I. to the Outer Banks of N.C. On the trip home, we got held up in heavy traffic at the Delaware Memorial Bridge, and again on the GW bridge in NYC. My wife's bike, a Yamaha V-Star 1100 Classic, shut down three times on the approach to the Delaware bridge, and the third time it would not restart. We waited an hour or so by the side of the highway-not pleasant. I'm not too sure having temp gauges would have helped, but I want them anyway-there was a whole lotta heat coming up from my cylinder heads, and it would have been nice to know if it was OK to keep going.
Andrew Macdonald
Via e-mail

Although I've never seen a color-keyed cylinder head temperature gauge, there are plenty of analog and digital ones on the market. Autometer, VDO, and Stewart Warner are just three that come to mind. You can order them with either a thermocouple (which fits under the sparkplug) or a thermistor (water jacket) sending unit. Obviously, you'll want the thermocouple type for your Guzzi. Expect to spend around 150 - 175 bucks for good one with all the mounting hardware.