"I went to ride the bike for the first time in ages, and the starter just clicked without turning over..."
"When I refit the battery, the square terminal nut drops down and the bolt won't reach it!"
Most riders have been through it at least once: a flat battery, and terminal bolts that just won't catch.
My own bike, an air-cooled single, the Honda XR250 BAJA (the Japan-market XR250 / MD30), had been sitting unused for a while, and when I finally went to start it, the battery was completely flat.
In this post I'll show how I took the battery out of the bike safely and charged it with a CTEK charger.
Along the way I also got to use the Ko-ken Z-EAL 5 mm hex socket I bought a while ago on a real job for the first time, and it gripped the bolts remarkably well. I'll also explain an old trick that uses a strip of 1 mm rubber sheet so the terminal bolts catch first time.
The battery charger I used
CTEK motorcycle battery charger (fully automatic) JS800 (now discontinued)
An automatic charger that checks the battery and gives it a maintenance charge. CTEK says it can also help recover sulphated batteries.
1. Removing the XR250 BAJA battery: first real job for my Ko-ken Z-EAL 5 mm socket
On the XR250 BAJA (MD30), the battery sits behind the left side cover.
First real job for the Ko-ken Z-EAL 5 mm hex socket
This was the first real job for the Ko-ken Z-EAL 5 mm hex bit socket, whose finish and precision I compared in detail in my previous post.
My previous tool review:
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[Stop Stripping Hex Bolts] Why I Switched to the Ko-ken Z-EAL 5mm Hex Bit Socket: Unbeatable Grip, Precision Fit, and Maximum Bang for Your Buck
"Does loosening stubborn hex (Allen) bolts on your motorcycle give you that terrifying feeling that the tool is about to slip and round off the bolt head?" "Have you ever stripped a seized fastener, only to spend a fortune buying extractors and screw-removal tools just to get it out?" Every home mechanic who wrenches on motorcycles has experienced the nightmare of a stripped bolt head. In fact, I’ve been there myself: while trying to remove a seized brake pad pin in the past, my socket cammed out and completely rounded the hex recess. I ended up having to buy screw ...
The moment I pushed the bit into the hex in the bolt, it slid in and locked in place with no play, almost as if it were magnetic.
The Z-EAL's thin, short design and very precise tip mean the ratchet doesn't tilt even in tight spots, and the torque goes straight into the bolt. The bolt came loose smoothly with no sign of damaging the edges of the hex. It reminded me how much more confident good tools make you feel.
With the side cover off, you'll see the battery held firmly in place by a metal bracket.
2. The most important safety rule: disconnect the negative (-) terminal first!
Next, loosen the battery terminal bolts.
There is one rule here you must never break.
The rule that prevents shocks and short circuits
- Removing: always disconnect the negative (-) terminal first!
- Fitting: always connect the positive (+) terminal first!
If you undo the positive terminal first and the metal of your screwdriver or spanner touches the frame or engine, you get a big spark from a heavy short circuit. It can blow a fuse, and it can also burn you or damage the battery, so always stick to "negative off first, positive on first".
I fit a magnetiser collar (the yellow ring) to the screwdriver shaft. It stops small screws from dropping deep into gaps in the frame and getting lost, which makes it a handy little trick for electrical work.
The battery (a Super Natto STX5L-BS, compatible with the YTX5L-BS) is out of the bike.
3. A simple trick: a strip of 1 mm rubber stops the terminal nut dropping out of reach
When you put the battery back in the bike, there's one thing that frustrates a lot of home mechanics.
The square terminal nut drops down under its own weight, and the bolt you push in from above can't reach its thread.
With the battery in the bike there's no room for your fingers, so you end up pushing the nut up from below with a flat-blade screwdriver while turning the bolt, which is a bit of a juggling act.
Here's an old workshop trick that gets rid of this annoyance for good.
What you need: 1 mm rubber sheet
I used ordinary 1 mm thick rubber sheet that costs very little at a DIY shop.
With a craft knife, cut a small rectangle about 7 mm wide and about 10 to 15 mm long (this is for the STX5L-BS / YTX5L-BS; for other batteries, just cut it to the inside width of the terminal).
Just slide the rubber under the nut!
With the square nut in the terminal, push the cut rubber in right underneath it.
The thickness and springiness of the rubber keep the nut pressed up towards the bolt.
That's all it takes. With the battery in the bike, you just put the bolt on from above and turn it, and it catches first time without holding the nut with your finger!
Points to watch
Make sure the rubber stays under the nut and doesn't stick out onto the top of the terminal, where the cable's ring terminal and the battery terminal touch. After the final tightening, check by hand that the terminal is tight and doesn't move.
4. Charging with the CTEK JS800: the reality of a seven-year-old battery, and why the kick-start matters
I took the battery indoors and connected it to my CTEK JS800 charger.
CTEK chargers are well regarded. They charge in several stages up to full, and CTEK says the pulse stage can help break down sulphation (lead sulphate crystals that build up on the plates of a weak battery).
This battery has actually been in the bike for more than seven years
There's something I have to own up to here.
The battery in this XR250 BAJA has been fitted for more than seven years.
I'm a little embarrassed to say that I let it go flat almost every spring after the winter lay-up, and each time I've brought it back on the charger and kept using it. It's a remarkably tough battery.
My honest advice: if your bike has no kick-start, replace the battery
Please don't think "if it lasts seven years just on a charger, I'll never need a new one".
The only reason I can keep using this seven-year-old battery is that my XR250 BAJA has an optional kick-start (kick pedal) fitted.
Even if the battery dies completely on a ride, I can still start the engine with the kick-start. That backup is what makes it possible.
If your bike has electric start only (as most modern bikes do), my view is that a battery that has gone completely flat, or one that has been in use for 3 to 4 years, should be replaced with a new one rather than nursed along on a charger. If it won't restart up a mountain or at a motorway services, the recovery bill and the lost time will cost you far more.
After that, I checked on the CTEK indicator that it was fully charged, then put the battery back in the bike using the rubber trick on the terminals. The engine started without any problem!
5. Summary: regular charging and careful terminal work
A flat battery can happen to anyone, but if you know the right steps and a couple of small tricks, getting going again is much easier.
- A precise tool (such as the Ko-ken Z-EAL) makes removing the bolts more reliable
- When removing the terminals, always start with the negative (-)
- Stop the terminal nut dropping with a strip of 1 mm rubber underneath
- On a bike with no kick-start, don't put off replacing the battery as it ages (3 to 4 years is my rule of thumb)
If you ever take your battery out to charge or replace it, give the rubber trick on the terminals a try. It should save you from those annoying bolts that just spin!
Disclaimer
The removal steps, rubber trick and charging described here are based on my own experience. A battery contains dilute sulphuric acid and gives off flammable hydrogen gas, so keep naked flames away and work in a well-ventilated place. Connect the terminals in the right order and tighten them properly at your own risk, putting safety first.
I've also written about taking the XR250 BAJA battery out before the winter lay-up.
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Honda XR250 BAJA Winter Prep: Removing the Battery (Tools and Steps)
Taking the battery out of my Honda XR250 BAJA for winter: the tools you need, the three side cover bolts (watch the collars on the top one), the two battery bolts, then negative terminal first and positive second.
I've written about servicing the XR250 BAJA starter motor in this article.
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Honda XR250 BAJA Starter Motor Strip-Down: Tools, Terminal Nuts, Washers and Brushes
Stripping a used spare starter motor for my Honda XR250 BAJA: the tools you need, the two 10 mm terminal nuts, washers you can't buy separately, the BC1693G oil seal, and checking the brushes against the 8.5 mm limit.
