Service
Service
(LUNK1f!HARLE? OIL-LEVEL ODDITY RE(AL(ITRANT GUZZI RkALL RO5TE~
WHO’D A THUNK IT?
Q: I just bought a 2013 HarleyDavidson FLD Switchback one * month ago, and it has 1,600 miles on it now. The only issue I have with it is a loud metallic “clunk” sound in the front suspension when I hit rough road surfaces. During my 1,000mile service at the Harley dealer, I had them check it out.
The technician said he hit every bump he could and the only noises he heard were coming from the “freefloating rotor,” and there was nothing wrong with the front suspension. Is this noise normal for this bike? And can you explain to me what a freefloating rotor is?
PHIL CENO FEHOLD, NJ
AH It are sounds simply as bottoming though you the B suspension. Your HarleyDavidson, like most motorcycles, has a hydraulic bottoming stop that prevents metal-to-metal contact when the suspension is fully compressed. Even when this stop is functioning normally, you’re likely to hear a clunk when the fork is bottomed. Further, the Switchback has a known issue with the design of its unique headlight nacelle, which, due to the part’s natural frequency, has a tendency to ring when the suspension bottoms.
It would still be a good idea to have the shop verify that the bottoming stop is present and functioning correctly. Provide the tech with exact details on where the issue is happening, and make sure the test rider is close to your size and weight, particularly if you are heavier than average. If you are, you might be riding your Switchback outside of its design limitations and need to increase damping and fit stiffer springs.
Regarding a “free-floating” rotor:
It’s a brake disc attached to the wheel via compliant elements that allow it to move freely axially (side to side), which increases brake feel, performance, and longevity. These elements would have to be severely worn out to cause the noise you describe.
LEVELING WITH YOU
My 2009 Honda XR650L uses a half-quart of oil every 150 * miles. Also, I have a problem with varying oil levels. The owner’s manual states that the oil level should be checked when the bike is cold then after the engine has been warmed up and idled for five minutes. Typically, I get a mid-stick reading before start-up, and then the level drops to below minimum after warm-up and waiting a few minutes before checking again. Is there an explanation for these widely varying oil levels?
DON RUSH MCKINLEYVILLE, CA
A Your oiling XR650L system, has which a dry-sump keeps oil away from the spinning crankshaft by removing it from the crankcase and directing it into a frame reservoir via an oil pump. A second oil pump maintains oil pressure to the various rotating and reciprocating parts in the engine. Over time, when the bike is stationary, oil held in the frame above the engine slowly bleeds through the tolerances in the pumps and into the crankcases. Because these pumps are designed to both evacuate the crankcase and keep constant oil pressure, it is a tricky balance that results in a variable oil level on the dipstick.
The owner’s manual states that you should run the machine on the sidestand for three to five minutes prior to checking the level. Our recommendation: Ride the motorcycle to the point where you shift it through all of the gears but not revving the engine very high. This will ensure proper warming of the engine and good circulation of the oil. If you rev the engine too high, the oil might froth a bit, resulting in an artificially high level at the dipstick. Do not vary the weight of the oil outside of Honda’s recommended iow-30 to iow-40 range because that could contribute to further inconsistent oil level readings. The key is to be consistent with your oil-checking technique so that you can spot a trend of oil loss. A large-bore air-cooled single, particularly one ridden off-road, needs to have its oil level checked often.
¿NG0T 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.
MAXIMUM CLEARANCE
G! Maxim I have a with 1983 Yamaha 19,000 miles. XJ550 The V I bike is in really good condition but will will not not start when cold. It will start with a whiff of starting fluid. I have checked compression—it’s 90 to 100 pounds. I also cleaned the carbs and installed new needles and seats. It is just not getting a rich enough mixture. What did I miss? ED DROVER MOORE, SC
A Anything below 100 psi cranking compression is quite B low. On an engine with a stock 9.5:1 compression ratio like your Maxim, the value should be more in the range of 150 to 180 psi if the engine is in good condition. So, first, verify your data by doing the test again, making sure the engine is warmed up (if it can be), the throttles are wide open, and the battery is fully charged to give maximum rpm while cranking. If the values after rechecking are similar, a valve-clearance inspection could be telling, though it’s unlikely that all four cylinders have tight intake or exhaust valves. One of the camshafts could have jumped out of time, leading to the low readings. You say you cleaned the carburetors and also that the engine is not getting a rich enough mixture, but you don’t explain. Have you verified the function of the enrichment circuits? Does the bike run well when warmed up?
ASK KEVIN
Q:Kevin, the cranks of Yamaha RD engines are easy to manipulate, ® and I’d like your thoughts on setting a 90-degree or 135-degree crankpin relationship to overlap the power pulse, like a long single? I realize a 180-degree twin is balanced and the secondary mode of vibration is missing, but instead there’s a rocking moment. I assume it would soften the rocking motion and add a second mode influence. How difficult do you anticipate balancing to be? This would be for a racer. And are there any possible traction or power-delivery gains?
ALEXPAPPERT
FROMCYCLEWORLD.COM
A This question has two antecedents. One was how tough ■ it was in the 1960s to make a Triumph 500 twin come off a dirttrack corner with a 500 BSA Gold Star single, and the other was Honda’s 1992 innovation of “Big Bang” firing order in its V-4 NSR500 roadracer (in it, they fired two cylinders simultaneously, then 68 degrees later, fired the other pair together). Somehow, the Gold Star and
Big Bang NSR got off corners faster than their competition. Why? It arises from the difference between static friction and sliding friction. It’s harder to get a big crate started across a floor than it is to keep it moving once started. It’s the same with tires. Both the Gold Star and the Big Bang NSR gave their power in widely separated pulses, leaving time in between for a sliding tire to regain its grip and be ready to deliver strong static friction to transmit at least the first part of the next power pulse. This cannot work unless sliding would otherwise result, as it depends upon static friction’s being greater than sliding friction.
Therefore, changing the firing order of a 250 or 400 twin probably
would not help acceleration off paved corners, since wheelspin is unlikely. On dirt, with lower grip, you might see some advantage to a close firing order. And, yes, there would be balance problems! As you note, with 180-degree firing, the engine rocks from side to side, and the closer it is moved to simultaneous firing, the more it will jump up and down because it is becoming a single. There will be no power increase, as neither cylinder “knows” what the other is doing.
-Kevin Cameron
Hard starting can have many causes, but the main culprit based on the information you provided is that you have a mechanical issue causing low compression.
NO THUNDER DOWN UNDER
QB has My progressively 2007 Moto Guzzi developed Breva 850 an * irritating refusal to start when hot. Forum data suggests it may be bad battery grounding or possibly a starterswitch issue, but that doesn’t seem to fit the problem, which is, simply, that the bike won’t start when hot. It is not a case of the starter relay connecting but going no farther because there is no “click, lurch, and stop.” Ignition on, dials swing, lights illuminate, confirm that it’s in neutral, pull in the clutch lever, press the starter: Nothing at all happens. Battery checks out fine. Bike starts perfectly well when cold. When hot, a push-start works. If I wait 30 minutes, the starter fires it up without hesitation. I have replaced the battery ground with a high-current cable, cleaning the connections at both ends. I have stripped and cleaned the handlebar starter switch. No joy.
I suspect a solenoid or connection has been cooked by engine heat.
Any suggestions would be welcome. Other possibilities might be the sidestand cutout switch or some error in recognizing neutral.
JOHN WHITE ADELAIDE, AUSTRALIA
A A few things might be happening here. Ensuring B that any electrical system is properly grounded is always a good first step. Now you must determine how far through the system electricity is getting. You will need a voltmeter for this. The starter switch on the handlebar should be getting at or near 12 volts. When the starter is pressed, the starter relay must be getting 12 volts. If there is no clicking sound at all once you press the starter button, the chances are the starter relay, which is a low-voltage switch, is not engaging. These relays are small and can fail intermittently. If the starter relay is engaging and 12 volts is getting to the starter itself, a starter amperage draw test should be your next step, but that takes a couple of specialized tools. The amperage draw should not be much higher than 55 amps; if it’s approximately 75 amps or more, that means there is a serious impediment to the starter.
The starter motors in Guzzis are an automotive type that flings the drive gear at the toothed engine flywheel during the starting process. Because these engines often stop in the same area of the flywheel after every keyoff, the gears can wear with each other in such a way that the drive gear hangs up on the driven gear instead of retracting back into the starter. This is unfortunately a common problem with Guzzis of all ages due to the design of the mechanism. The next time the no-start condition occurs, tap on the starter with a rubber or plastic mallet while simultaneously pressing the start button and you will most likely find that it will unstick. Putting the machine in gear and rocking it back and forth might also help free the starter, but do not attempt to start it while it is in gear.
If that isn’t the issue, the starter itself may be going bad and have a dead spot on its commutator. A low battery charge often results in an overstressed starter, which can result in failures.
HOT MONSTER IDLES TOO FAST
I have a 2002 Ducati Monster 620 that starts and idles fine * until it gets hot from riding, at which point it idles at approximately 3,000 to 3,500 rpm. Any ideas?
MARISA MERCONE ROCHESTER, NY
A On a 12-year-old bike like yours, air leaks are a common H cause of high idle. Their presence can be detected quickly by spraying a combustible such as WD40 sparingly at the carb bodies and intake manifolds while the machine is running. The idle will increase if there is an air leak in the area where you sprayed the fluid. To help determine the precise area of failure, inspect components such as the intake boots from the carb to the engine, the fuel mixture screw on the lower part of the carb near the engine, and the constant velocity diaphragm mechanism at the top of the carb. Each has rubber components that can degrade, resulting in a poor seal and a high idle.
RECALL ROSTER_
NHTSA RECALL NUMBER: 14V044000 MANUFACTURER: Yamaha Motor Corporation, USA
MODELS: 2009-13 YZF-R1s manufactured between October 2008 and August 2013;
2012-13 Super Ténérés manufactured between October 2011 and August 2013.
NUMBER OF UNITS AFFECTED: 24,000
PROBLEM: On certain of these motorcycles, use of the headlight may generate enough heat to cause the bulb connections to expand, resulting in arcing in the headlight bulb socket that can cause the socket to overheat, melt, and cause the headlight to malfunction. This increases the risk of a crash.
REMEDY: Yamaha will notify owners and dealers will replace the headlight socket, free of charge.
The recall began in February 2014. Owners may contact Yamaha at (800) 962-7926.
