Thermostat Mod - Let it Flow

I just got ahold of a service manual for our bike and read that the thermostat opens up when the coolant reaches 70.5*-73.5*C / 158.9*-164.3*F (see page below). What I'm wondering, is if anyone has tried replacing the Thermostat with one that opens up at a lower temperature. This would allow coolant to flow more readily especially on my short commutes to/from work.

160 degrees is actually already pretty low for a thermostat to open... most cars open at 180 degrees for example. I wouldn't want it to run any colder than that, as a cold motor isn't as thermally efficient (less power) and the motor is designed to run at a certain temperature range (above 160, below boiling) for maximum efficiency. The whole point of the t-stat is to ensure that the motor reaches and stays at that temperature range.

skierd wrote:

160 degrees is actually already pretty low for a thermostat to open... most cars open at 180 degrees for example. I wouldn't want it to run any colder than that, as a cold motor isn't as thermally efficient (less power) and the motor is designed to run at a certain temperature range (above 160, below boiling) for maximum efficiency. The whole point of the t-stat is to ensure that the motor reaches and stays at that temperature range.

I agree with this post.

You could always try to contact Yamaha and see if they will say is ok.

But it will most likely be denied.

That was an old drag racing trick...just remove the t'stat...it's only running very short, major bursts.
There's no time to throttle coolant in a quarter mile any way.

Anywho, todays engines are more precise and use more variety of materials.
I plan on goin more than a few miles so...I think I'll go with the temperature than the yammy enginneers decided was tolerable.

The tolerances of all the different pieces of my engine were decided by the temperature they would operate at. You change that temperature...so should your tolerances be considered.

the thermostat opens a passage to the radiator, cooling the engine.....until the 'stat opens, the engine cooling system is running "closed loop" to warm up the engine faster...if you install a lower opening 'stat, the coolant will flow to the radiator faster, not allowing the engine to reach operating temp until later.....if you want to "warm" up faster, put a higher opening 'stat or pinch off the hose to the radiator...the 'stat also throttles any in-rush of colder coolant, preventing extreme temperature seizure, so be weary of running without it....trying to run a different operating temp also causes the ECU to modify its ignition timing, so again, be careful what you do....

Curious, at what temp does the bike turn the temp light on at?

I do a 10km ride to work and 10 back. Never had an issue with the bike not warming up fast enough even in temps around 0-3c. Personally I tend to leave this type of thing as OEM because the bike is designed to run at that spec, not before or after.

I would also be curious to know at what temp the:

1) yellow temp light comes on
2) red temp light comes on
3) what is the critical temp for the engine

Preferably in celcius. If any body has this info, please come forth.

Thanks

Personally, I wouldn't change the T-stat. This was a big issue with one of my previous rides, Honda ST1300. One of the biggest known issues is the failures of the Tstat. What happens is it sticks open. This hurts fuel mileage, because in any kind of cold weather, the bike doesn't reach its designed operating temp. So unless you like giving more money to the oil companies, I'd suggest against it.