I have as 2006 Gasgas EC 300 and recently put on a Trail Tech Striker with speed and water temp capabilities. What I found was that my bike would never get above 150 degrees while riding. I even tried to get it hot by slowly going around in first gear. Even stopped and idling or revving the engine it barely got to 170 before I gave up. I am considering putting in an inline thermostat in the right radiator line. I saw a 2011 with one installed, and was wondering if this was ever a stock option, or what the best aftermarket option is. I am thinking 165 or 170 should be the minimum temp the engine should be at.
Radiator Thermosat
- Thread starter 2stroke
- Start date
I removed my thermostat. Well, plus it melted when I burned the bike down. But my Gasser runs cooler than all my friends orange bikes. The only time I have ever boiled my bike is when I am really beating on it in the boulders using lots of clutch moving really slow. Even then, not very often.
I found the single thermostat was of little use. During casual riding there is enough flow through one rad to keep the bike cool, so the thermostat doesn't do much. If you were riding hard and abusing the clutch, then it would get hot enough to open up. I removed my thermostat.
I have the Trail Tech Voyager and set the amber warning light for 160*F. I set the red warning light to 180*F. I got stuck on a hill on a very hot day and that was the only time I've ever had the amber light come on.
If you really want your bike to maintain temperature, you would need a thermostat on both sides. The temperature recording function shows that my engine stays at 130*F for most of my riding. I mounted a large Clarke tank and don't use shrouds. I do however have the Checkpoint alloy impeller.
I have the Trail Tech Voyager and set the amber warning light for 160*F. I set the red warning light to 180*F. I got stuck on a hill on a very hot day and that was the only time I've ever had the amber light come on.
If you really want your bike to maintain temperature, you would need a thermostat on both sides. The temperature recording function shows that my engine stays at 130*F for most of my riding. I mounted a large Clarke tank and don't use shrouds. I do however have the Checkpoint alloy impeller.
I will continue to ride it to make sure it is a problem. 150 just seems very low to me. That's colder than most outboards run at. The thermosat kit I like the most is the thermo-bob and it has a 175 thermosat that I think is perfect. Maybe these bike are designed to run cold, but any engine I've ever seen is best off 180+, and no worries until about 220-230. Coolant shouldn't boil until 250 or so.
dANbOT
New member
Agreed, when my snowmobile hits 160 due to poor snow conditions I pull over to cool it down.
My last bike (CR250) had a Vapor and it averaged around 140 unless i was abusing it.
I guess a better question is why do they have to run so cold? Is that just how the tolerances of the engine are measured?
Maybe you are just messing with me. There is no way you will ever keep an engine that cold, and even if you do it will either A. Cold seize, or B. the top end wont last long. My bike won't even run right until its above 140F (60C).
So if nobody has an actual reason for the engine to run so cold, I'm going to put in a thermostat and enjoy consistent jetting, and longer engine life.
dANbOT
New member
I don't think anyone is messing with ya. 2 strokes just run that cool, or at least anything I've ever owned with a temp guage did.
127 is the operating temp of my last few Polaris snowmobiles. The only time they ever get hotter than that is if there is no snow to cool the heat exchanger.
At about 180 warning lights start flashing, and shortly after it will go into a limp mode to protect itself.
127 is the operating temp of my last few Polaris snowmobiles. The only time they ever get hotter than that is if there is no snow to cool the heat exchanger.
At about 180 warning lights start flashing, and shortly after it will go into a limp mode to protect itself.
I don't know about snowmobiles, all I ever owned were air cooled. Boats are about as cold blooded as they get, with a constant supply of cold water. Even the old ones run 140 thermostats, and the newer ones are higher. Unless there is a major issue I am missing, all you are doing by allowing an engine to run cold is shortening its life.
swazi_matt
Active member
Having removed a plug from a hot engine, your numbers seemed a bit low in my opinion so had a quick google of other forums (so you decide if it is gospel or gossip) shows optimum 2t temperature to be 160+
Nearly every engine I have ever seen runs best at 165-200 degrees. I don't know why dirtbikes would be different.
(F5)
Gold Level Site Supporter
Roadracing. Yes you can get it that cold. Provide a large enough radiator, a fairing that promotes ducting and a decent speed. Good gas, sharp jetting, high comp, optimum ign timing and lots of revs. Yes cold temps will stave off detonation and allow max power. Anything above 50 (degrees c) and you're losing power. Extra wear? Who cares? it will be rebuilt after a set mileage.
This is an extreme that just isn't relevant to dirt bikes, but it bookends the opposite scale from where you are heading for illustration. I'm not proposing you try to maintain that temp.
60-70 is nice and safe and probably has best wear reduction and gives headroom to allow you to pump another 30 degrees of heat energy into the system during that killer uphill slick draggy mud track before risk of boil over. If you don't have that overhead there is nowhere to store the energy and there is little water to store extra energy.
So why does your bike run so badly at low temp? I often wondered that but the answer it appears is the light end gases which are required to ease starting but are the first to degrade. They start degradation in any system open to air. Gas stations have methods to reduce this but let's consider your vented carb that hopefully you've ran fully dry from the last time you rode the bike. Then the plastic gas tank on your bike that breathes much more than metal and has a vent of course. And how long you've stored the gas in a plastic jerrycan.
The vapour of a degraded gas doesn't atomise very well at low temps but the hot metal will sort it out once up to temperature so it appears that old gas is just fine in normal use to the average user. But they do note that the engine runs like crap till you've gone through the gears a few times.
Cold seizes are about the delta of the rapidly expanding low mass piston and a slowly heating water cooled barrel.
This is an extreme that just isn't relevant to dirt bikes, but it bookends the opposite scale from where you are heading for illustration. I'm not proposing you try to maintain that temp.
60-70 is nice and safe and probably has best wear reduction and gives headroom to allow you to pump another 30 degrees of heat energy into the system during that killer uphill slick draggy mud track before risk of boil over. If you don't have that overhead there is nowhere to store the energy and there is little water to store extra energy.
So why does your bike run so badly at low temp? I often wondered that but the answer it appears is the light end gases which are required to ease starting but are the first to degrade. They start degradation in any system open to air. Gas stations have methods to reduce this but let's consider your vented carb that hopefully you've ran fully dry from the last time you rode the bike. Then the plastic gas tank on your bike that breathes much more than metal and has a vent of course. And how long you've stored the gas in a plastic jerrycan.
The vapour of a degraded gas doesn't atomise very well at low temps but the hot metal will sort it out once up to temperature so it appears that old gas is just fine in normal use to the average user. But they do note that the engine runs like crap till you've gone through the gears a few times.
Cold seizes are about the delta of the rapidly expanding low mass piston and a slowly heating water cooled barrel.
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barossi73
Gold Level Site Supporter
In other words,fresh fuel,dont cane it till its good and warm,and dont worry unless it boils!
As a m8 who has owned a heap of bikes said...i had never worried about eng temp on any of my bikes until i got one with a temp guage and started paying attention to it...
F5 in the above m8's garage he has two of the old rd's,a 350 and a 400.true classics nowadays
As a m8 who has owned a heap of bikes said...i had never worried about eng temp on any of my bikes until i got one with a temp guage and started paying attention to it...
F5 in the above m8's garage he has two of the old rd's,a 350 and a 400.true classics nowadays
(F5)
Gold Level Site Supporter
I was storing a 350 till recently. At the dyno lockup there's 2 400s, a later 350LC, a later still RZ350, and another in an RG chassis. I want to own a 400 at some stage, have had the RD350 back when I was 17. 2nd bike in my SIG list below is RZ350 based but only the cases and gearbox are std.
And yes your first line summation is sage advice to live by. I would have saved a lot of electronic ink if I was smart enough to write it so succinctly.
I can only really add, 'cover the rear brake when hoiking a monsta wheelie'
And yes your first line summation is sage advice to live by. I would have saved a lot of electronic ink if I was smart enough to write it so succinctly.
I can only really add, 'cover the rear brake when hoiking a monsta wheelie'
