Service

Service

LED UPGRADE RICH VICTORY ODO OFF? LOW-VOLT CB ASK KEVIN

RAY NIERLICH

Want extra light at night? Aftermarket LED auxiliary lights will provide the most illumination. Or upgrade your stock bulb with more wattage.

SHOULD I RETROFIT LEDS?

Q: Are LED headlight bulbs a worthwhile upgrade? Which ones are best? Are they compatible with headlight modulators? I want more light for desert riding at night and would greatly appreciate some advice about the current crop of LED bulbs!

STEVE TATREAU ENCINITAS, CA

A: It is the Wild West out there in the world of retrofit LED lighting: lots of claims being made but not much proof to back them up. The technology is evolving quickly. LEDs produce a narrow swath of light, so the lens and focal length are critical for good results. They also heat up in operation and require an effective heat sink to survive. You get what you pay for.

At the present, I would still keep your incandescent headlight bulb. Just optimize the situation by fitting a relay if the bike doesn’t have one and perhaps a slightly higher-wattage bulb, typically 85-watt for a 55-watt. Then buy some quality auxiliary lights. We have been impressed with the Clearwater lights (clearwaterlights.com)—not inexpensive but well made and in the US. For desert night riding, Clearwater recommends its Krista lights. If those don’t scorch the earth well enough for you, upgrade to the Erica lights. They will plug right into the same harness.

RICH VICTORY

Q: We bought a 2014 Victory Cross Country Custom. Having problems with it running too ricn and dying all the time. It has a Power Commander. Does it need to be flashed and retuned, or does it need to be dyno tested?

LORI JOHNSON CYCLEWORLD.COM

A: Modifications are the first thing to suspect when you're experiencing trouble. Especially since your bike is relatively new and is usually a quite reliable model. Start with the Power Commander. You don’t mention why a Power Commander was installed, what map is in place, or if there are any other modifications. One easy check would be to read the map installed and set it to zeroes versus stock, or you could simply remove the Power Commander completely to check how it runs. Your bike doesn’t have to be dyno tested to find out what is wrong, but if it isn’t too inconvenient or expensive, have a good dyno guy run it while reading the exhaust with an 02 sensor and mapping it that way. Or install a Dynojet Auto Tune to build the map as you ride.

KLX ODO WOES

Q: First, I'm proud to say I've been a subscriber since 1968 (the Yamaha DT1 issue!). I've been wrenching on motorcycles since then and can usually fix a mechanical problem. Since this one appears to involve electronics (black magic), I am stumped. I bought a gently used 2004 Kawasaki KLX400S dual-sport (after having spent many miles on its clone, a 2000 Suzuki DR-Z400S). When I got the bike, I noticed the odometer was all goofy. At first I thought the whole unit was off, but the speedometer is spot on, based on comparing with friends and radar speed traps. The odo shows about two-thirds of the actual mileage I rack up. Any ideas how I could get it repaired (Suzuki and Kawasaki want about $675 for a new one)? The cable and drive are fine. There are occasionally used 400SM speedo assemblies on eBay, but aren’t they calibrated differently for the 17-inch front wheel, or do they use a different speedo drive?

ERIE BICKEL PENN VALLEY, CA

A: Wasn't seeing that DT1 a I seminal moment? Like the first I time you got kissed by a girl, not your mom. All the inputs for the gauge are from the same speedo drive on the front wheel. If your speed is correct and the odo isn’t, the problem is in the gauge. No parts are available.

Dumb question: Do you have the correct display selected? The display should have “ODO” next to the number.

If it shows “RT,” that’s ride time for the last ride displayed. If your gauge really is the culprit, forget swapping the original for one from an SM and get yourself a TrailTech Digital gauge (trailtech.net/ digital-gauges). All TrailTech gauges replace the original head and sensor.

GOT A MECHANICAL OR TECHNICAL PROBLEM with your beloved ride? Perhaps we can help. Contact us at cwservice@cycleworld.com with your questions. We cannot guarantee a reply to every inquiry.

550-FOUR!

QI ® but recently out-of-tune inherited 1975 a Honda running ■ CB550. One of the issues that eats at me is the charging system.

The original voltage regulator was faulty, sending 16.1 volts to the battery.

I replaced it with an aftermarket regulator/rectifier, which now only sends 12.1 volts to the battery at idle (1,200 rpm) and 12.3 volts at around 4,000 rpm. The resting voltage of the battery is 12.6 volts. I sent the reg/rect back to the manufacturer, who tested it, said it was fine, and returned it to me. I removed the stator and had that tested by an old mechanic friend who told me it appeared to be fine. I checked the resistance figures in the six-gang stator lead, and the results correspond to the values given in my shop manual. I have also checked and cleaned all the wires coming off the ignition switch.

My questions: Are there any other likely culprits to check before inspecting the entire wiring harness?

If I should inspect the stator, since I personally didn’t, what should I test and look for? Alternately, is there any mechanical risk in riding a bike only charging at 12.1 volts?

MIKE DOBIN CYCLEWORLD.COM

A ■ to Your keep bike up isn’t with charging the load enough if the ■ measured voltage is below the battery resting voltage. It is running the battery down. All will be swell until the voltage falls below 9 volts or so, and things quit sparking all of a sudden. The CB500 and 550s were great bikes. But one weak point is the charging system. The original charging system will not reach “break even” until above 3,500 rpm. If any additional electrical loads beyond the ignition are added on, such as headand taillights, turn signals, or brake light, the alternator has no reserve capacity to compensate for these extra loads, at any rpm. Back in the day, when these bikes were used for short trips with lots of restarts or ridden in slow traffic with the headlight on, they would run the battery dead in short order.

Most bikes have a permanent-magnet alternator with the excess current produced shunted to ground through the regulator. Your bike utilizes an excitedfield type of alternator, similar to most automotive alternators. The regulator simply varies the current to a wound exciter coil to vary the output. This coil is located in the center of the alternator cover, with a segmented steel flywheel revolving around it. The stator windings that produce the current for charging are mounted around the OD of the flywheel.

The harness is almost never the problem. It is smart to check the grounds, harness connectors, and battery condition before wasting a bunch of time chasing your tail. Then check the exciter coil with an ohmmeter for an open circuit or a short to ground. Before, when your old points-type regulator was sticking, it might have fried the exciter coil. The good news is that Honda finally realized this malady and came out with an improved, higher-output (more windings of finer wire) exciter coil in 1977 models, which you can fit to your bike. The improved later coil was part number 31101-390-005. The earlier part number was XXXXX323-XXX. (The 323 is the product code for CB550.) That new voltage regulator may or may not be so good, but now you can check the current (that’s amperage plus or minus) at the battery and see.

One last thing: Make sure the brakelight switch, located near the rear brake pedal, isn’t sticking on. This is quite common, and the poor thing can’t keep up if the brake light is always on.

ASK KEVIN

MODERN PISTON ON OLDER FOUR-STROKES?

Q What is it that prevents a modern piston design from being used in an older model four-stroke with the long full-skirted piston? I have a feeling the stroke has something to do with it and thus rod angularity and thrust. It would be nice to incorporate some of the newer tech into older model big-bore kits to reduce weight and friction.

jEFFSWAN PARKVILLE, MO

A Quite a few adventuresome builders ■ have taken this route, but the results have generally been poor. Here’s why.

The bucket-like pistons of olden times had to be fairly heavy to provide enough heat-conductive metal to carry away the extra heat absorbed by the domed pistons ofthat time. Their domes could not be made as thin as modern pistons, which in turn could not be cooled without oil jets (think of those 112mm ashtrays in Ducati’s Panigalel). So the old-time pistons had to have thick domes to conduct heat outward to the walls, and the thickened region behind the rings then carried that heat down the considerable length of the skirt (tapering as it went) to spread that heat over a large skirt surface area and out to the cylinder wall through the oil film. In other words, those pistons were made that way in self-defense against heat.

You are right that the mini-skirts of newer pistons would cut friction and weight. Also, the modern arrangement of using very short wrist pins in pin bosses that are nothing but short “stalactites” hanging down from the flat, thin piston crown (less reciprocating weight means reduced bearing loads and losses) would do the same.

Another point: Pistons run especially hot in air-cooled cylinders. During World War II, makers of large air-cooled radial piston engines for aircraft had instant problems with ring, piston, and cylinder scoring, plus detonation and piston failure when hostilities began. Why not before? Training aircraft are flown conservatively because who knew when Congress would cough up the bucks for replacements? But when war comes, throttles go to the wall. So a frantic effort to bring down piston temp began-from steel cylinders with integral-machined fine-pitch steel fins, to pressed-on machined-fin aluminum “muffs,” to caulked-in thin aluminum sheet-metal fins, set into shallow grooves on the outside of each forged-steel barrel (each B-29 cylinder had 54 of these!).

But air-cooled bikes don’t cruise to the target on steady 70-percent power, and this is what made them practical in their time, always slowing for cops and corners.