One problem too many - electrical riddle??

[will3200]

Hey all, wondering if you can help?

I have had my BT125 scooter for almost 3 years from new and have done over 12,000 km. In general terms it has served me well but there have been a few challenges along the way. I started with no practical knowledge of bikes and their systems and have slowly built up a bit of knowledge trying to learn and do the work myself when I can.

My main problems started after I went away for a month or two and when I returned the bike would not start. In the process of diagnosing a faulty spark plug I flattened the battery. Without a charger I went to the kick start which worked perfectly with the theory that the battery over a week or two would charge its self. This worked ok but it would only charge the battery enough for one or two starts before a prolonged period of riding was necessary for it to work again. Eventually I accepted defeat and took the battery to the local garage for a charge. I was assured by the mechanic that their charger was a smart charger and it would be charged at the right rate. On reconnecting my battery and going for the starter things took a turn for the worst. After one a quick bust of the starter I noticed some smoke coming from the bike which I suspected was the starter. Reverting to the kick start, the bike started immediately and I continued to use the bike while I in theory worked out the problem.

A week or so after the previous episode I returned to my scooter after there had been significant rain. My bike had been covered up but what follows may suggest it was not enough. On driving home i found that when i had the indicators on and then braked for a corner, the blinkers (left or right) would stop flashing and would both instead light up without flashing together along with the dash back light.

Since getting home I have been unable to start the scooter again, kick start or electric. My first theory was that the water had got into the electrics causing a short. Remaining optimistic I left the scooter for a few days under cover with the hope that drying out would fix the short but unfortunately not. When you squeeze the rear break before going for the kick, the dash lights up with both indicators fixed. If you do kick, you get nothing like the spark plug is not sparking. As I only recently changed the spark i think it’s more realistic for it to be some other problem.

Today I have spend the day going through the electrics system trying to understand what is going on and find possible causes. After taking off most of the panels for access, i still cannot see anything significant and am none the wiser. I have also been trying to match the electrical circuit chart that I have to with what i can see but my limited knowledge of electrics is making it challenging.

My only theory that links everything together is a faulty CDI that was caused by the start after the battery was charged.

If anyone has any advice I would love to get to the bottom of this problem.

Cheers
Will

[Rebel]

Welcome to the forum.

Electrical problems are sometimes very hard to track down. I'd look at all contacts for corrosion, look for faulty wires. You are going to need to find the source of the smoke you saw, the smoking part probably needs replacing, then look at that circuit to find out why it was smoking.

If your battery is the one that came with it, the battery may have gone past its useful life and charging might not be enough to keep it up.

Since you are not getting a spark, you could have a CDI problem, and it is a high fail part so replacing it is reasonable.

[will3200]

I will have another good look and maybe order a new CDI. The batter is a bit over a year old and it was something i had considered although when I took it to be charged, the battery man said it should be ok after checking it with some special multimeter.

I will keep the forum updated on progress

Cheers

[jmkjr72]

yeah dont trust motorsports batteries at most places they dont know how to deal with them
they need to be charged at a lower rate then other batteries
and take from a guy who worked at a place that sells batteris those fancy multimeter checkers are worthless nothing beats a good onld fashioned load tester when checking a battery out

i would start looking for the wire you fired and fix that before you even do any thinge else

[Rebel]

Looking forward to hearing what you find out.