Yamaha TRX850 Enthusiasts Forum

Went to start the TRX a day or two ago after it had spent the day in direct sunlight, and the starter relay just clicked away rapidly with the bike only occasionally half turning over, managed to bump start the bike to ride home, on the way I noticed the tachometer reading lower than normal rpm and occasionally flickering, I also thought the indicator warning lights were a little dimmer than normal, after 10 miles or so the bike starting missing and eventually stopped, I coasted to a halt, it wouldn’t start on the button but I did manage to bump start it again and it ran fine all the way home. Stuck it on a trickle charger but it fails to charge , yet it starts on the button now easily? Would a faulty battery cause this, should I change it first, it’s three years old and has always been kept on a trickle charger, thanks Steve.

Are the wires tightly screwed on to the battery terminals?

Some batteries can be dead after 3 years though, it's not unheard of. If you turn on the headlight and put a multimeter on the battery, does the voltage keep dropping like a stone? If it gets below ~11v right after being on charge then it's probably time for a new one.

Thanks, I’ll try changing the battery first then.

It probably is the battery, but check it first before you change it, it may still be ok.
Also check that the wiring is good, check the earth connection to the chassis, under the battery box.
Check the connectors on the stator, rectifier, etc, if they look at all corroded it may be possible to pull them apart, clean them then spray with inox or similar one you have it back together. If the bike gets a bit of weather the dialectric grease packed into the connector body will help.

+1 on the dialectic grease. Do it on most of my leads n plugs as a safe guard

Turned out the stator had been fitted the wrong way around such that the three AC wires were catching on the rotor and eventually worn through, surprised it lasted as long as it did, but glad I’ve found something obvious!

Glad you found it, but it proves once again that electrical problems are usually caused by something else.
In motorsport it has been a long standing tradition to attribute a DNF to "electrical failure" when what actually happened was that the con rod broke, punched a hole through the block and smashed the alternator, thereby causing the electrical system to fail.