Service
Service
RAY NIERLICH
BIKER BELCH
Q: I have a 2014 Harley Electra Glide Police (FLHTP) motorcycle. I have an issue with filling the 6-gallon gas tank. When the gas gets up to the top, I have to stop, shake the bike back and forth to make the gas go into the tank so I can put in more. Sometimes I can put in 1/2 to 1 gallon more after the gas comes up to the top. Eve asked several other riders who have the same bike and they say they have the same problem. Is there something wrong with the ventilation of the tank, or am I missing something?
TIM BARGY CYCLEWORLD.COM
A: The police editions can either be Road King based (with right-side fuel fillers) or Street Glide based, which have a center fuel filler. I’m assuming yours is the latter. When filling on the sidestand it will take a jiggle or two to burp the air pocket that gets trapped when filling. If you overdo it, you may be filling the carbon canister as well (California models), via the vent port in the filler neck. The tanks are rated as 6-gallon, but almost 1/2 gallon is consumed by the fuel pump/sender/plumbing inside, so 5-1/2 gallons is more accurate.
MAX RUNTIME
Q: My 2005 Yamaha VMax engine dies after about 15 minutes. I have to coast to a stop and then it starts right back up. The engine dies while just riding a straight road, no bike leaning of any kind. The speed is usually about 65 mph. We have checked: plug connections, stator, regulator rectifier, main ground wires, relay, fuses, and even installed a new battery. Please help before I put it in the Classifieds for salvage value.
MARTIN GONZALES CYCLEWORLD.COM
A: Good job checking the grounds/ battery/charging first, but we need more info. Does it quit all of a sudden like the key was turned off (ignition trouble), or does it bog and slow to a stop (fuel supply problem, restricted tank vent, bad pump, plugged fuel screen/filter, etc.)? Will it quit after idling for 15 minutes or only if being ridden? (It requires more fuel when being ridden.) Does it backfire when it dies or does it go silently into the night? (A single backfire is the electronic ignition signing off, whereas a quiet end is usually a bad connection/ battery voltage problem.) The trouble you’re experiencing seems to be timeof-operation related, since the condition is repeatable. You say it just dies, which leads me to think it has to be something that affects all the cylinders at once. This rules out the individual high-tension coils, carbs, etc.
I constantly admonish you guys to check spark first. But in your case I’m breaking my rule. Do a quick check to rule out fuel starvation first. Check the fuel tank vent to ensure it isn’t restricted. If the vent is okay, scope it out before riding off and take tools with you. When it quits, qui ckly open one of the float bowl drain screws (with the little black drain hose) to see if gas runs out. No gas and your pump is DOA or something is plugged up.
HIGH-CARB DIET
Q: I've never messed around with carburetors before and was won dering if I can go from an HSR42 to an HSR45 or 48? What do I need to consider? Does fitment to the head change? Will it affect other parts of the motor so much so that I need to make a separate modification just to accommodate a bigger carb?
EDUARDO HARRIS CYCLEWORLD.COM
A: The Mikuni flat-slide carbs you mention are some of the best carbs ever. The same rules of physics apply to these as well as any other carbs. Since you neglected to mention what bike you own, I can offer only general rules. Engines are designed as a system. Just increasing the carb bore size will lead to a loss of low-end torque and poor throttle response, unless other modifications to increase flow are adopted at the same time. Typically, the easiest improvements are fitting a lessrestrictive exhaust and a less-restrictive air cleaner and/or airbox. Power gains will become exponentially more expensive as you proceed with items such as wilder cams, larger valves, larger/ higher-compression pistons, and so on.
GEAR DRIVE WHINERS
Q: I am considering a cam upgrade for my ’03 Heritage and am debating on the chain versus gear drive. I see people complain about the gear drive having issues (mostly crank run-out), but I also see everyone worried about the tensioner wear issue. Has anyone done a long-term test on a gear drive setup?
JASON MAUN CYCLEWORLD.COM
A: Pick your poison and go for it. Harley cam drive problems seem to happen mostly on the internet, not it real life, so stop worrying and ride more. There are a bunch of aftermarket cams available as well as the Screamin’ Eagle brand. Gear-driven cams will be noisier than the OE-type chain-driven ones. If sticking with chain driven, replace the tensioner at the same time. Some folks feel timing is more precise with gear drive, but on a street machine this is an imaginary gain.
CELL CELL REGENERATION RE
My 2013 Harley-Davidson Switchback has 31,000 miles on it and has received every service at the dealer since new. While riding in the Colorado Rockies the bike just died at 45 mph. I coasted to the side of the road. There was plenty of gas and battery cranking power. After trying to start it at least a dozen times over two hours, I towed it to a Harley dealer who said it started on first try, but it died on a test ride. A “bad battery cell” was diagnosed and they sold me a battery. It has not died since after 5,000 miles. My local dealer told me it could not have been the battery if it had cranking power. What else could it be in case it happens again?
PHIL CENCI STATEN ISLAND, NY
A: Batteries with a bad cell can’t “fix” themselves, so if that was the issue the engine wouldn’t have started again after it quit. Perhaps in the course of replacing the battery a loose ground was inadvertently fixed?
ASK KEVIN
WHY HEAT?
Q: In his article about the new H-D MilwaukeeEight engine, Kevin Cameron, states: “By switching from modified hemi two-valve to nearly flat four-valve, the surface area through which heat can enter heads and pistons has been substantially reduced.” I inferred that this was an improvement. To a non-engineer, it would seem that forthe same amount of heat generated, having a greater surface area to absorb and dissipate it would be better. Am I wrong?
MIKE SULAK WEST, TX
The only source of power in an internal combustion piston engine is the extremely hot highpressure gas that results from the combustion of the compressed mixture of gasoline and air. Heat is rapidly lost from this gas into the much cooler metal combustion chamber and piston surfaces, so it is essential that the exposed surface area of piston and combustion chamber be as small as possible to minimize the heat loss. Heat loss from combustion gas causes its pressure to fall, which reduces engine torque.
Combustion should be as rapid as possible to minimize the time during which rapid heat loss takes place.
These are not just a matter of theory; in the case of the Meyer-Drake/ Offenhauser turbo engines run at the Indianapolis 500 in the 1970s, reducing combustion chamber surface area by making the chambers shallower and piston tops flatter resulted in an 80-hp gain.
And when Keith Duckworth built his V-8 “DFV” Formula 1 engine in 1967, its low-heat-loss, close-to-flat combustion chambers and piston crowns enabled it to outrun Matra’s higher-revving V-12, whose old-style deep combustion chambers and tall piston domes rapidly sucked heat out of combustion gas. -Kevin Cameron
NEW OIL OVERFILL QUESTION
Q: Is there any reason BMW techs refill the final drive of a 2011 R1200R with only 200 milliliters of oil? Coming out of the factory these bikes came with 220. Is there any harm in doing this oil change with 220?
HUMBERTO C. MARTINEZ
CHAPARRAL, NM
A: Your R1200R takes 180 milliliters of oil on a change. The 220 you mention is for another model. Chris Hodgsen of San Jose BMW says since the gear oil is thick, they fill their beaker to 200 to allow for the 20 or so that clings to the sides. BMW final drives aren’t fussy about the exact lube amount.
DRAIN BOLT CURE
Q: I have a 2014 Yamaha Bolt. When removing the oil drain plug to change the oil the threads in the aluminum housing came out. Now the drain plug will not tighten. Are there any oversize drain plugs that may be re-threaded into it?
RANDYHAYNES
CYCLEWORLD.COM
A: Stripped oil drain holes are a common malady. Oversize drain plugs are readily available. But please don’t do it. Install a solid-type thread repair insert into the hole (such as a Timesert; timesert. com) and then you can still use the stock plug. I prefer a solid insert over a wound-wire type (Helicoil or similar) for applications where the pieces will be disassembled frequently, such as spark plugs and drain plugs. There is less chance of the insert winding in or out after several uses. A warning: Installing either type requires carefully re-tapping the drain hole straight and true, which is harder than it looks if you’ve never done it before.
GEARING DOWN
Q: I have logged about 5,000 miles on my new Bonneville T120.1 find the gearing to be too tall for my riding style. Would increasing the rear sprocket size from the 37-tooth stock to a 42-tooth from the Thruxton be about right for me? The forums I have found indicate sprockets can be changed without ill effect, but my dealer and Triumph customer service both say this cannot be done on rideby-wire motorcycles with traction control and ABS because it could cause the motorcycle to “function improperly.” They say there is no way to work around this.
ED TODD MECHANICSVILLE, VA
A: I see no problems. My local dealer says it will work too. I suspect corporate lawyers frown on any tampering with the motorcycle.
