Starter doesn't connect

[Jambo]

Hi guys. Tryed to start the bike the other day and it fail.
I suspected the battery was low so I ordered a OPTIMATE charger and charged the battery.
With battery fully charged I installed it on the bike and it did not start. Same grinding noise.
Starter is burnt? Is there a way to know? btw the battery is a EXIDE AGM and the charger gave the thumbs up.
Last few times it actually started, the starter was turning rather slow.

How should one diagnose this properly?

Cheers

[KiwiCol]

I'd start with the earth and power connection to the starter. Check they're tight & in good clean condition.   Run a multimeter over then whilst trying to start it & check the voltage going into the starter.  If that's all good, time to look into the starter motor itself I'd say.

[Irish in Oz]

Try another battery.

[grog]

Jambo, multimeter on input wire to starter. Try starting, if you have above 11.5 trying, starter is stuffed.

[gsxbarmy]

Also check that the main earth lead from your battery to your frame is good.

https://gsx1400owners.org/forum/index.php?topic=4828.0

[Big Phil]

This type of fault is almost always an earthing problem. In this case with the heavy current being drawn at starting there is a high possibility the ground leads have become brittle and hence high impedance. I would attach a temporary parallel ground (earth) lead from the battery to the engine and another from the engine to the frame. If it still doesn't start then the starter motor is probably faulty.

[Irish in Oz]

It could be any combination of connections negative or positive, or even the starter relay

[Big Phil]

Yes I absolutely agree it could be anyone of those issues Oz. But surely you have to begin somewhere??? I would start from the basics and that is the main ground (earth) wiring connection first. One it's easy to do and secondly it's probably the most common fault. It's happened to me twice!

[Irish in Oz]

I like you Phil
Calling me Oz instead of Irish 

[Big Phil]

Sorry Mate but that's made me laugh. Irish becomes an Ozzie😂

[grog]

No need for any temp wiring, just use multimeter at different points.Much easier.

[Irish in Oz]

No need for any temp wiring, just use multimeter at different points.Much easier.

Easy for those that know Grog, but even the experts get caught out.

[Big Phil]

Not so in my opinion Grog. A multimeter will still show a ground between battery, engine and frame under most conditions however small the connection remains. When you are starting a bike the current draw is at its highest point. If the ground cable is adding resistance due any number of issues, it reduces the current (and hence power) which is available to start (turn over the engine) but it does not mean this will be seen as a fault on a multimeter. Even under load with a faulty ground cable a multimeter may and probably will still give a zero or very low ohmic measurement. Say what you want and stick with theory but I will always go by an actual physical test .

[Irish in Oz]

That's why you should keep it simple stupid, jump start with your car battery, if it turns over OK then it may be connections, short out the starter motor relay with bike battery only if it turns over it may be relay, if it doesn't it may be battery...................

[Irish in Oz]

Sorry Mate but that's made me laugh. Irish becomes an Ozzie😂

No hope of that I'm too clever