I thought that I would share some of the knowledge I have gained while having a starter motor with a problem obviously not experienced by many stromtroopers.
I commute on a wee with 125000 KM on the clock. The motor was overhauled at 90 000 KM and obviously they skipped the starter.
I had an intermittent issue where the wee wouldn't start, and then it would. For the life of me (and for the love of reading threads on starter motor problems
) I could not find the issue, until one day. None of the forums/threads mentioned my specific problem, which I will detail in the later parts of this post.
Please note that I am not a mechanic, but I like problem solving so this guide does not come with any guarantees.
So, here is my step by step guide to troubleshooting your starter motor issues:
*** Diagnosing the problem (whether intermittent or not) ***
1. When you turn on the key (bike in neutral and engine switch ON):
- Do you get headlights?
- Hear the fuel pump priming?
- Do NOT see "check" on display?
If ANY ONE of the above is NOT true, your problem exists before the starter and this guide is not going
to help you.
2. When you hit the start button (with clutch lever pulled in):
- Do you hear a click? (This is the starter relay)
- Does the starter motor spin (faster than usual)?
- Does the starter motor spin and engage but seem "weak"?
In my case, it was the 3rd one. I assumed it was the battery, but I was sorely mistaken.
Now, once you have the answers to the above questions, you can start to look at the cause.
*** Checking the cause ***
1. Hearing the click - This indicates that there is indeed current flowing to the starter relay. You should get a multimeter hooked up to the relay to see how much current is flowing (before and after the relay). If there is a difference, your relay may be finished.
Broken/Damaged wires may result in not getting enough power to turn the starter motor.
2. Starter motor spinning but not engaging - This indicates that the starter is getting power and is spinning, but is not engaging the motor. This could be the result of a siezed starter gear (the gear on the starter motor shaft not moving into position). You would have to start by removing the starter motor and examining the gear/shaft (which is the commutator). Feel if it moves freely. It should be a heavy movement as the commutator fills the inside of the starter motor. Then you can reinstall the starter motor. The next thing to check would be in the left-side engine cover. Once removed (after draining the oil first), you will see the starter motor clutch (as seen here: http://www.ottway.net/vstrom/internals4.jpg
- Thanks to RudyRedHead). This is the "big gear" behind the stater. With the engine cover off, "mock start" the bike to see if the small gear on the bottom left turns and whether is turns the "big gear". If the big gear does NOT turn, you will need to replace the starter clutch. Replacement of this part requires a rotor pull and some specific knowledge of the configuration so I would suggest taking it to the shop for that.
3. Weak starter motor - As I said, this is the problem I had on my wee and it turned out to be a minor repair. If there are no broken/damaged wires then the "weakness" almost certainly comes from worn/broken brushes within the starter motor. I followed the instructions in a very comprehensive youtube video (Linked here: Service a starter motor: worn brushes - YouTube
- Props to TheOverEngineer). I got new brushes from a dealer, but the guy details how to make replacement brushes from secondhand car brushes which you can get from any scrap yard for cheap cheap.
Hopefully by this stage, you have been able to at least pin-point the cause of your starting problems and I've saved some of the hairs on your head.
For the mechanics out there, please feel free to correct any of the points if you know better, I will not be offended.