What's the deal with the temperature gauge?

Dry Martini said:
No they use slow reacting gauges because most car owners are stupid. The first gen miata had a real oil pressure gauge. Then in 95 they changed to an idiot gauge because too many owners began questioning why the gauge was "fluctuating".


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Miata owner?

Well I thank you all for pointing out the specifics of the operation of the cooling system. Now knowing that this engine among most motorcycle engines is built to run hot, or at least be able to, and that the thermostat starts opening at a very low temperature while the fan cuts on at around 212*, I still have to ponder why such an extensive range of operating temperatures is allowed. It's certainly not optimal. But maybe it was just more expense than it was worth because obviously, like stated before, the engine does perform and hold up well. It really just sacrifices cold weather fuel efficiency. Oh well. It's not a big deal, just curious.


But the real situation is probably just what drymartini just mentioned: I'm just stupid and it's showing now that I'm driving a vehicle that has a real temperature gauge rather than a graduated/slow reacting one!
 
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BlackAndBlue said:
Miata owner?

Well I thank you all for pointing out the specifics of the operation of the cooling system. Now knowing that this engine among most motorcycle engines is built to run hot, or at least be able to, and that the thermostat starts opening at a very low temperature while the fan cuts on at around 212*, I still have to ponder why such an extensive range of operating temperatures is allowed. It's certainly not optimal. But maybe it was just more expense than it was worth because obviously, like stated before, the engine does perform and hold up well. It really just sacrifices cold weather fuel efficiency. Oh well. It's not a big deal, just curious.


But the real situation is probably just what drymartini just mentioned: I'm just stupid and it's showing now that I'm driving a vehicle that has a real temperature gauge rather than a graduated/slow reacting one!
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Yes, I was a miata owner, a 92 and a 95. In no way was I calling you stupid. I was referring to the many people who bought them because they were "cute convertibles".

I doubt Yamaha is worried about cold weather fuel efficiency on a 600cc sportbike. [emoji1]


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I know you weren't. I wasn't being sensitive! I was just saying your general idea of people over reacting if they see the real time actual temperature of their engines because they don't know any better is pretty accurate.
 
BlackAndBlue said:
...........I was just saying your general idea of people over reacting if they see the real time actual temperature of their engines because they don't know any better is pretty accurate.
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Bingo! You have just identified about 85% of all motorists (but don't quote me on the number as it has clearly no scientific data to support it). Vehicle manufacturers have moved away from informative instrumentation as most people just don't want to be bothered. I had VW Scirocco awhile back that would constantly eat through the temp sensors in the radiator, that would trigger the fan, so I ran the ground through a rocker switch so I could start the fan manually when I noticed the gauge getting to high.
Back on temp, mine starts around 212F as well. +1 as mentioned above as these high tech engines are designed to run best when hot, or warmed fully.
As a side note, about 20 years ago I was standing next to Roger Penske's indy car in the pits and I asked one of the mechanics how long they warm their race engines - he said about an hour before running it hard. ;)
 
in all seriousness on hot days and nights and running down the road at "normal" rpm i see around 191. come to a stop for a bit its going to 215 before the fan comes on and gets it to 205 or so. seems in any weather riding around in 1st or 2nd gear such as in parking lots will see the temp climb to 210-215. i have seldom seeing 220's unless i have come to a stop and turned the bike off, then the key back on

under regular "mild" days say up to 80 degrees i will see 174-181 under normal riding conditions
 
my bike climbs to 180 fairly quickly and stays between 180 and 190 while riding. rises to 214 when I stop (on a hot day) before the fan comes on. 68,000 miles like this.... normal

if yours stays around 160 while riding then I'd say the thermostat is not allowing it to warm up to 180... I'd replace it.
 
Slightly off topic, but does anyone have any good tequniques for cleaning the bugs off the radiator thoroughly without damaging the radiator?
 
Hint: look closely at the top of the guard. If lift up (two hooks it hangs from), it comes off at the top and you can stick your soft wash mitt in there and clean the front. Soak it several times to bring the bug parts to a flexible state and most will hose off once the larger chunks have been removed w/mitt. :thumbup:
 
Each engine is designed for specific operating temps...

To compare Yamaha apples to oranges, here's the operating temp range for a YAMAHA, 4 stroke, 150 HP, inline 4 cylinder, OUTBOARD ENGINE; 136F-158F

It runs considerably cooler so it will NOT cause salt water use to cook salt in the block and ultimatly block the coolant passages.

As a side note, the newer FJR's have a digital coolant temp gauge. It jumps easily 15 degree's F just due to the design.... Temps are about the same as the FZ6 too...
 
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I suppose that now would be a good time to confess that I do not subscribe to the idea that just because an engine does something that it was designed correctly and specifically to do just that. You cannot be suggesting that the tendency of the fz6's engine to fluctuate 52* during operation is ideal for that engine and exactly what the designers wished it to do? No, I believe there's a compromise in there somewhere.
 
BlackAndBlue said:
I suppose that now would be a good time to confess that I do not subscribe to the idea that just because an engine does something that it was designed correctly and specifically to do just that. You cannot be suggesting that the tendency of the fz6's engine to fluctuate 52* during operation is ideal for that engine and exactly what the designers wished it to do? No, I believe there's a compromise in there somewhere.
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Well you are stating the variation from Tstat opening temp to fan on temp. That is a bit misleading. The range is more like 180-212, 180 being the temp of a fully warmed up engine to stop-n-go riding.




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Lol I just hate the mileage I get when the bike won't warm up passed 160ish on a cool-colder day...It's a difference of like 6MPG! That's over 10% of my total MPG lost for no reason!

I may look into changing the T-Stat because it's ludicrous
 
iviyth0s said:
Lol I just hate the mileage I get when the bike won't warm up passed 160ish on a cool-colder day...It's a difference of like 6MPG! That's over 10% of my total MPG lost for no reason!

I may look into changing the T-Stat because it's ludicrous
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I stopped worrying about gas mileage when I increased my rear sprocket by two teeth. [emoji1]


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iviyth0s said:
Lol I just hate the mileage I get when the bike won't warm up passed 160ish on a cool-colder day...It's a difference of like 6MPG! That's over 10% of my total MPG lost for no reason!

I may look into changing the T-Stat because it's ludicrous
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FWIW: 5SL-12410-00-00 YAMAHA THERMOSTAT ASSY

A little "where used" on our beloved stat.... Just a couple of bikes. :eek:
Moral they must be out there but a little difficult to find. Get me 175F and I'll try it!
 
iviyth0s said:
Lol I just hate the mileage I get when the bike won't warm up passed 160ish on a cool-colder day...It's a difference of like 6MPG! That's over 10% of my total MPG lost for no reason!

I may look into changing the T-Stat because it's ludicrous
Click to expand...

A lot of vehicles seem to have poorer mileage in cold ambient temperature even at equal operating temperatures. I notice this extended highway drives, so the extra fuel consumed at startup is somewhat moot.

I'm guessing it has something to do with the intake air being more dense, and thus requiring more fuel to maintain a stoich AFR. That said, that should produce more power and thus you would require less throttle to get the same power which would equal things out when cruising. However, it doesn't seem to pan out like that. This is where I run out of smarts. :)
 
beatle said:
A lot of vehicles seem to have poorer mileage in cold ambient temperature even at equal operating temperatures. I notice this extended highway drives, so the extra fuel consumed at startup is somewhat moot.

I'm guessing it has something to do with the intake air being more dense, and thus requiring more fuel to maintain a stoich AFR. That said, that should produce more power and thus you would require less throttle to get the same power which would equal things out when cruising. However, it doesn't seem to pan out like that. This is where I run out of smarts. :)
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Not for a long stretch of highway, short trips yeah it makes a huge difference because of the longer warmup, but I've seen little difference in mileage in my car if it's cold out or not on longer commutes. The bike gets terrible mileage when its temp sits around 160 degrees, it's beyond frustrating. My old Ninja 250 didn't seem to have that difference a change in cold weather...and that was carbureted!
 
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