Did my thermostat just... start working?

So I've had my VFR for well over a year now, put on almost 10,000km and had gotten pretty used to how long it took to get the engine up to VTEC temperature. From my house to the first back road it would never be up to VTEC unless on the hottest of days with a healthy warm up in the driveway. On cold or rainy days the bike would often just barely get up to 70'C on my 25min commute, or sometimes not at all. But since a few weeks ago I noticed the bike was heating up a lot faster. First I figured I was just doing something different, or wrote it off as just a fluke, but now I'm sure something is different. The bike is now consistently VTEC ready by my first backroad, even in temps around 10'C. It used to take minutes to climb the ~35 degrees from operating to VTEC, now it just takes seconds. The bike still seems to cool down just fine, this morning it spent most of the ride at 77'C which is pretty normal for a 17'C morning, it's just that it went straight up to 80 and then bounced between 80 and 74 till it settled. This would seem to make sense with a thermostat opening at ~80 and closing at ~75, but it didn't do that until recently.

Thoughts?

 

The VFR take a few minutes to reach operationg temperature 110°
If you let it seat to idle it would take few more minutes to reach 150°
Depend on the climate, it will take longer if the weather is cold.
When is the last time you check and flush the coolant?
How many mile on your bike and what is the maintenance you have done?

 

I got the bike with 10,000km on it, and now it's about at 20,000km. The coolant has likely never been changed.

 

My 5th gen takes about 2-3 minutes to reach 75-80°C when driving.
You should replace your (12 yo) coolant. I flush and replace mine every 4 years.

 

Agreed, coolant flush/change is due.

 

After I bought my 2001 VFR, one of the first things I did was flush/fill all of the fluids. Good thing too, the clutch/brake fluid looked like coffee! The PO had actually put too much oil in the motor too and the bike was really hard to shift, unitil I did a proper level of oil! The coolant wasn't bad but I wanted to get all of the fluids replaced, as I don't know when the last time any thing was serviced as the PO was the second owner and did not know the previous service history. The suspension was actually swapped out for better legs, but that would have been on the list too.

Have you checked the level recently? is the reservoir at or below the limits? Maybe you're low on coolant and it's actual warming up faster due to low coolant level.

 

There's plenty of healthy blue coolant in the reservoir. And it's possible the bike has had the coolant changed as I've only had it for one of its 12 years, I just can't be sure what maintenance the PO did, let alone the dealership that sold it to me. The dealership changed the oil and there's a set of 2009 tires on it, so there's been at least some maintenance. Regardless, it has no trouble staying cool once it touches 80'C, it just gets there in a jiffy now. In 20'C weather it still hangs around 80'C on the back roads, 90'C in town and when I'm stuck in a jam the fan still comes on at 105'C and cools the bike down to 100'C in a few seconds.

 

I have always used red G30 or G40 coolant for both my bikes and cars, never blue G11 which might cause electro galvanic corrosion. Green G48 is also ok.

 

I just did my coolant...changed it to the Toyota Long Life Red coolant...i dont really warm up my bike, i leave the house at 440am and my bikes too damn loud in my quiet neighborhood to leave it idling for a warm up so i turn it on for like 30 seconds and off i go to work. By the time i get on the freeway the temps are around 130degrees which the freeway is like 2 miles away.

 

My 2000 seems to have the same temp readings: I just did a coolant change today & refilled with 50/50 premixed blue-coolant, silicate free & safe for aluminum engines. Don't notice cooler running, just the same as before: maybe the new coolant transfer heat from engine to coolant better so coolant temp is normally hot for a VFR?