Yamaha TRX850 Enthusiasts Forum

had a quick search through the forum, didn't see what i was looking for. apologies if this is a repeat topic.

so;

i'm not too impressed with the high temperature at which the fan decides to kick in.... is it a popular/reasonable mod to add in a manual switch? (obviously keeping the thermostat for those rare occasions when you just forget to switch it on and then kill the bike by overheating, derp)

if so, where's a good place to look?

Never heard of a trx overheating, but thats not to say its never happened,
Re the switch, it would be fairly easy, take a live from some where in the loom that switches off when you turn the key to the off position, and then to a one way switch and from there to the power in side of the rad fan motor, the motor should have its neutral connected permenantly,so it would just be the addition of a switched live.

well, i wasn't particularly worried about the bike "overheating" per se... just that in hot weather and stationary traffic, i'm not that comfortable with the bike sitting at over 100 degrees before the fan finally decides to kick in.

i mean, quite apart from anything else, the coolant is water. it's got stuff in it and the boiling point will be higher, but it's still not great.

i'd be much happier if it kicked in at around 85 or 90.

yeah i'll have a browse around. fitting a simple manual override would be highly preferable for hot sunny weather.

this isn't urgent, of course... just a personal preference. i want to take care of the thing =).

Your coolant SHOULD be 50 / 50 ethylene glycol and deionised water, and remember it`s a pressurised system so it`ll not boil til at least 120 degrees, maybe higher!

The water / coolant is also under pressure, this raises its boiling point considerably.
I have a bypass switch on mine though.
Be sure to fit it to the left side so you can switch with your clutch hand, not throttle hand.