Tech Tip - Battery Life

When should I replace the battery in my bike?

I've known John since he purchased his Sportster new in 1998.  I haven't seen John in a while due to moves kids, pets and job changes.  So, it was a surprise to see him at the service counter on Monday evening.

It turns out John is looking to sell his bike.  And he needs a battery to get it running.  This time of year, we see a lot of people come in for a replacement battery, and looking at the date codes on the old batteries we get an idea of approximately how long a battery will last in each of the types of bikes (turns out it's usually between 3 and 4 years with good battery care.)

John didn't have his battery with him so I asked him how old his battery was.  Turns out he was replacing his original battery!  That's over eleven years of service out of his original battery.  That's an exceptional life for a battery on a Sportster.  John attributed the long battery life to several things:

• He always pulls the battery out of the bike during the winter and brings it inside the house
• He keeps the battery on a Battery Tender battery charger inside the house
• When he's installing the battery every spring, he uses a corrosion protectant on the terminals

John didn't mention this, but after working on his bike a few times, I know he also tightens the heck out of his battery terminals to be sure the bolts don't come loose.  When the bolts come loose, the connection will arc and build up corrosion on the terminals and cables.  This can make the bike difficult to start and even prevent charging, leading to shortened battery life or even being stranded with a bike that won't start.

While John was at the counter explaining his battery care tips, another rider was nearby and overheard our conversation.  He remarked "I replace the battery in my bike every two years.  I can't afford to be stranded if my battery decides to die on the way to The Roundup or a bike blessing."

So, there you have two extreme opposites of the battery spectrum. John, whose original battery lasted and amazing eleven-plus years, and Earl who replaces the battery in his Street Glide every two years for peace of mind.

Ride Safe.
Chris Hajer

Tech Tip - Backfiring or Popping on Deceleration

More than likely your engine is "popping" not really backfiring. Backfiring, is extremely rare these days with electronic ignitions and the high reliability of engines. Real backfiring means the engine is not properly timed and the fuel/air mix is getting a spark and ignition at the wrong time (when the intake valve is open). Real backfiring is actually the bike "spitting up" in a sense, backwards through the carburetor or intake.

 

So, the popping you are hearing is not back-firing. It is a popping resonating sound generated by a lean condition on deceleration. When you suddenly close the throttle, the incoming air is choked off and the closed throttle also causes the bike to return to idle on the very lean idle circuit. However, momentum of the bike is actually "driving" the engine in a sense, and that engine is still spinning at rpm that needs far more gas than the closed throttle position can provide. The engine is still spinning but the incoming fuel rate is very low, until just enough builds up in the combustion chamber to "fire" on the exhaust stroke of the engine.

Don't "change the plugs" like some people suggest, it’s a waste of time and money. Messing with the ignition timing really won't help either, because it is still a lean fuel/air mix on deceleration that is the cause. ( I said cause and not problem, because the popping is not at all damaging to the bike).

 

 Often people think their bike is not tuned properly after the addition of “aftermarket” mufflers because of the additional popping they hear. Stock mufflers provide a lot of volume for the rumbles and popping in the exhaust to be toned down by resonating in the larger muffler canister. Motorcycle builders also have to meet sound regulations along with emission standards. Some of that sound proofing is in the mufflers. But, aftermarket mufflers that offer easier breathing, and are usually lighter and smaller, don't offer that same volume (Less volume = less sound attenuation = more noise and more popping). Modifying the exhaust (especially if it gets louder) will only make the popping louder. Because most aftermarket pipes produce "lower back pressure", to add to the popping; aftermarket pipes also tend to lower back pressure this will cause the fuel/air mix to lean out. So don’t worry about that popping you sometimes hear and enjoy this year’s riding season.


Tony D.
Service Manager
Wild Fire Harley-Davidson

Tech Tip - New ride Woes

Tony from Mount Prospect recently brought in his 2002 Sportster XL1200 Custom with just 965 miles on it.  The bike was beautiful; immaculate and nearly brand new.  This bike is new to him, having just purchased it from a friend, and he had a few concerns.

1. "There's a noise like air blowing in the front end of the bike."

That's a pretty odd description of the problem, but at least I know where to look (and listen).  After a couple of minutes of discussion with the customer I determined that the noise goes away when the brakes are applied.  This is good information.  I took the bike for a quick ride, got it up to speed, then turned off the motor.  I heard the noise the customer was describing (I'd describe it like a "shush, shush, shush" from the front end.)  The noise also went away when the front brake was applied.

After verifying that the rotor was not warped (front brake lever did not pulse when applied) and that there was fluid in the master cylinder (the sight glass was dark) I explained that the noise he was hearing was perfectly normal.  It's caused by contact between the brake pads and the rotor.  The brakes on some bikes make an intermittent sound, like this one, and other make more of a constant "shhhhhhhhhhhhhhh" as the wheel turns.  So long as brake function is normal, this noise by itself does not indicate a problem.  Concern addressed.

2.  "Speedometer stopped working."

This one is easy to verify (during the test ride for the front brake noise, I verified that the speedometer was not working.)  The lighting on the speedometer was still working, but the trip odometer and speedometer were not working.  There are only a couple of things that can fail with this system: a) speed sensor at the transmission, or b) the speedometer itself. 

Being a 1200 Custom and subject to the excess vibration in the handlebars, I thought in this case it might be the speedometer, NOT the more common speed sensor.  I removed the seat to get at the connector for the speedometer tester and immediately found the problem.  The wiring from the speed sensor to the speedometer had been disconnected. It looked like someone had recently installed a battery and either moved the connector and it came undone, or unplugged it.  In any case, after putting the connector back together, I was able to verify on another test ride that the speedometer was working.

In the process of looking over the motorcycle to address Tony's concerns, I found and fixed a couple additional problems.

1. Left hand controls were loose.  This was a common problem on the 1200 Customs due to the type of handlebars on the bike and the way they're mounted.  Harley-Davidson even had a recall for the mirrors on this bike due to excessive vibration and mirror breaking.

2.  Top front motor mount bolts were loose.  Sportsters prior to 2004 (non-rubber mounted) were all subject to these bolts loosening up and sometimes even falling out.  Any time there's a lot of stress on a fastener, like this one, it's subject to loosening up.

3.  Throttle cables had too much free play.  This is a maintenance item.  The throttle control needs to have a certain amount of free play to be safe when the handlebars are moved, but the free play in these cables was excessive.

It's interesting to note that the customer knew about two of the concerns, but the other three problems were not mentioned at all.  That's the benefit of bringing your bike in for service.  We have trained technicians with years of experience on all the Harley-Davidson and Buell models. We can quickly and easily diagnose AND repair issues like these, while you wait.

Ride safe!

Chris Hajer
Service Manager
Illinois Harley-Davidson