Readers’ Technical Questions


A friend advised I pick up a power pack jump starter this past summer, before I left on a cross-country ride of about 6000 miles. I selected a well-reviewed and not inexpensive unit on Amazon, charged it per instructions and headed west for four weeks, during the hottest time of year. I never used the power supply and left it in my side case after the trip for another few weeks. When I unpacked, I was concerned to see the lithium-ion battery had swollen enough to burst the plastic case of the device. I rode through plenty of 100-degree weather and the outside temperature reached 112F near Las Vegas. Since I live in a hot climate, is there any design of these units that is safer or less likely to self-immolate when stored in my saddlebags during hot weather? I like the idea of backup power, but not at the risk of spontaneous combustion in my luggage. —J. Worth

I’d say this is a manufacturing defect. li-ion cells typically have a max charging threshold of 113F and upper storage limit of 125F. You possibly exceeded that limit, since it was much hotter in the pannier. At higher temps, you risk damaging them due to reduced internal resistance and over charging. The cycles should decrease but the battery shouldn’t distort, especially since the thermal runaway temp is 300-500F, where they will begin to self-destruct. I haven’t seen slightly higher temperatures cause ruptures, but it will deplete the life of the battery on a progressive scale. I typically see leaking from age, poor quality manufacturing and when overcharged or overdischarged. I have a vehicle starter pack from Amazon that is a year old. It was stored in the back of a black car through Arizona summer. Ambient reached 120F and up to 160F inside. Temps stayed above 110F for six months and my garage maintained 120-130F. The starter battery, several flashlights and my Shorai li-ion motorcycle battery have not expanded. I could probably buy a few dozen batteries from China and find some that do expand, as their quality control is not to the standards of U.S., Japan and Germany. It is possible the manufacturing process had a short, causing excessive voltage bleed, a fast internal drain, overheating, expansion and rupture. Once a short occurs, it will continue to discharge until depleted or the short loses contact between the cathode and anode. This causes exciting thermal events and insurance claims! Another possibility is the electrolyte was not contained and ate through the case. Dispose of or return it, but do not use it. LiFePO4 batteries work well in heat. They have very high operating and thermal runaway temps and are considered one of the safest li-ion batteries, but are not the highest capacity. They also sustain better than lead acid batteries. The 18650 batteries seem to work well, I’ve heard some are LiFePO4 and there are many battery packs using them on Amazon. I have had no swelling issues and have cycled a couple of dozen. You could also potentially source a cell with a metal case on it, which is used to keep it from deforming in high heat. Enersys does this with its military cells, and civilian versions are sold as Odyssey brand, but this may not exist in the emergency starter market. —Kevin O’Shaughnessy

I bought a 2012 Ducati Multistrada used, and it runs great. I have 12,000 miles on this bike and need to pull the fairing and gas tank this winter to replace a bad fuel sensor (common defect for this bike). Since I will be that close to the valve heads, I wondered about checking the valve adjustment early? If I check and adjust at 12,000 miles, would I be good until the next scheduled valve service? If I do not check the Ducati’s valve clearance at 12,000 miles, the next convenient interval for me would likely be at about 17,000 miles (I ride about 5,000 miles per season). Checking at 12,000 or 17,000 is most convenient, so I do not tear the bike down during riding season and lose a couple of weeks waiting on shims. —Bob Hill

Maintenance intervals are guidelines, rather than limitations. Fortunately, our bikes usually don’t explode if we drive a mile, or even couple of thousand miles, over the suggested amount, but the longer you delay, the more chances of bad things happening. Time is dependent on the loads you put on the system. Some of the older Desmo systems required 2,500-mile checks, but we’d check valve clearances every race. For wear reduction and preventative maintenance, sooner is better than later. For OEM tests, we were allowed a 10-percent buffer of the mileage block. For instance, between your intervals of 14,000 and 29,000 miles is a 15,000-mile block. A 10 percent buffer would allow ±1,500 miles at OEM test standard. The exception is the first break-in service. Never cut the mileage short and only allow up to 100 miles over the target. New bikes have special settings, fluids, production waste material and contaminate metals caused by break-in, which can cause excessive wear over time. It’s best to have the bike serviced by the dealer within a hundred miles of the initial break-in mileage. If you don’t have records of the break-in service, in which the valves would be checked, you should inspect the valves sooner than later. If your bike feels down on power, overheats or misfires, check clearances as soon as possible. These are symptoms of tight valves which could lead to accelerated wear. I do see wear on this type of valve train more than shim under configurations. It’s possible you’ll need to replace shims. As you said, prepare for a wait, so try to identify shim resources locally or that will ship quickly. A check at either 12,000 or 17,000 miles would only be a couple of thousand miles out from 14,000, which should be fine. The measurements are not hard to do, but there are a decent amount of plastics and pieces to remove on the Multistrada. You should check clearances with the sensor fix, since you’ll need to take off many of the same parts for both services. Also, consider belt condition. These are interference engines. A broken belt will cause the valves to hit the piston and bend. Newer Desmo specs are 15,000-mile replacement, during each inspection. They run about $80 each, which is much less expensive than a new valve train. —Kevin O’Shaughnessy

The E3 spark plug information is somewhat incomplete. First, the “C” shape of the ground electrode is how the E3 got around the international patent of the LSGBrisk “Halo Plug,” from the Czech Republic. To increase the size of the kernel, the E3 has an excessive gap to start with, which seriously compromises the life of the plug. In two separate cars, both got about 7,000 miles before the E3 plugs failed due to excessive gap erosion. On my 2004 BMW R1150RT, I found no improvement in gas mileage, or performance. The 2003 and earlier engines had a single spark plug, and complying with U.S. emissions introduced a severe case of surging. In 2004, BMW added a second spark plug to the RT to eliminate the problem, and to a large extent it worked. The only side effect was when coming off the freeway, it felt as though the drive shaft was no longer connected to the engine and you were coasting. In 2005, I found LSGBrisk’s Halo Plug. Before I could install these plugs, I had to reset the ECU MOTRONIC unit by pulling the fuse, or disconnecting the battery for a few seconds, as it would cause detonation if I didn’t. The first ride on a freeway was a lot different, with engine compression braking all the way to idle, and fuel economy improved by 3-5 mpg. If you don’t know if the engine in your vehicle has knock sensors, I suggest disconnecting the battery for few seconds as cheap insurance. —Tom Buckley

Zero change in fuel economy and performance is what I’ve seen from most “performance” plugs. It’s interesting the E3 plugs failed so quickly. I’m a skeptic, but open to new possibilities. You are correct, a wider gap will wear faster, due to higher voltage requirements and heat. I’d speculate the huge electrode surface areas would still reduce combustion efficiency. The improvement from the Brisk is not expected, but I find it interesting that you had similar gains to what Dave had on his 2012 KLX250S. I’m curious why the E3 worked on Dave’s 250, but not on your autos and why the Brisk plugs worked on your bike? I’d love to do dyno testing back to back and on the same vehicle. I expect some of these results may be due to the condition of the previous component or a problem that was inadvertently fixed during the plug swap. Big gains in fuel and performance from a plug could indicate preexisting ignition problems, which could be caused by worn plugs. I find it fascinating to hear about gains and losses due to different designs, but I haven’t personally seen big gains from plug design. I do see big gains when replacing badly worn plugs with new ones. For instance, after 100,000 miles, I didn’t notice the slow reduction in power and fuel, but the check engine light came on. My vehicle was throwing O2 sensor codes, due to plug misfires. The iridium plugs were backordered and time was tight, so I got nickel. I replaced the badly worn iridium plugs with the nickel and immediately noticed it accelerated better. Within a day, long-term trim adjusted, codes disappeared and economy increased a couple mpg. The immediate observation would support that nickel plugs were a performance improvement, true in comparison to badly worn plugs. A week later, I replaced the nickel plugs with stock iridium plugs. The nickel plugs were still good, and the burn quality looked normal. The new iridium plugs increased fuel economy slightly, but there was no additional performance change. The nickel plug would probably continue to work fine until it wore, but may carbonize the combustion chamber over time from inefficient burning. I don’t do everything by OEM standards, but when it comes to plugs, it’s a must. Newer engines are very sensitive to change. An inefficient plug could cause misfires, carbon deposits, hot spots, preignition and detonation. For emissions, it’s in the best interest of OEMs to create a clean and long-lasting spark condition, so trust them.