2011 thermostat setpoints

[Berkyboy]

We've had a couple of technical questions on the new thermostat found on the 2011 Gassers. At this point there is no technical data from the factory so I fired up my wife's tea pot and came up with the following "unofficial" data.

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At normal ambiant temeprature (the motor is cold) the thermsotat allows an estimated 5% bypass.

In fahrenheit degrees the thermostat does the following.

At 135 degrees (during an increase in temperature) the thermostat begins to open allowing approximately 50% of maximum flow.

At 140 degress (during an increase in temperature) the thermostat is open to its maximum.

Once the thermostat is open all of the way (at 140 degrees) is does not begin to close again until the temperature has dropped to 130 degrees where it closes down to about 50%.

At 125 degrees (again during a drop in temperature) the thermostat closes fully where it only allows the earlier estimated 5% of flow.



No I'm not an engineer....but I did stay at a Holiday Inn Express last night.

 

[Troy F collins]

We've had a couple of technical questions on the new thermostat found on the 2011 Gassers. At this point there is no technical data from the factory so I fired up my wife's tea pot and came up with the following "unofficial" data.

___________________

At normal ambiant temeprature (the motor is cold) the thermsotat allows an estimated 5% bypass.

In fahrenheit degrees the thermostat does the following.

At 135 degrees (during an increase in temperature) the thermostat begins to open allowing approximately 50% of maximum flow.

At 140 degress (during an increase in temperature) the thermostat is open to its maximum.

Once the thermostat is open all of the way (at 140 degrees) is does not begin to close again until the temperature has dropped to 130 degrees where it closes down to about 50%.

At 125 degrees (again during a drop in temperature) the thermostat closes fully where it only allows the earlier estimated 5% of flow.



No I'm not an engineer....but I did stayed at a Holiday Inn Express last night.

Yep that would be about right.....on my Trailtech I saw no less than 50 C(125F)on a very cool day...and max temp was 60C(145F) as it warmed up during the ride.....on a hot day one would expect to see normal temps 80-90 C

I have always been on the fence about thermostats on off road bikes......but on a very cool day its nice to know there is some heat kept in the motor

 

[Berkyboy]

Thats the beauty of the Trail Tech computer when it is hooked up to the motor is you can keep an eye on the motor temperature especially on colder rides or when the motor starts running hot before it does any damadge.

Orignally I was on the fence about the thermostat but now that we are doing a little winter riding agian its nice knowing the motor is running in the zone somewhere between 125 and 145 degrees.

We used to block off both radiators with cardboard and listened for knocking if we weren't getting enough cooling.

 

[Bobt250]

Although it's something that can fail I think it's good to keep the engine at a more uniform temperature. It's just another example of how GG sells a bike that's completely equipped. The thermostat was on my like list from the start.

I'm putting a Trail Tech on mine so no worries for me.

 

[Skidad]

KTM's 2 strokes have been coming with the stat for years. Almost NEVER hear of a problem failure. My 97 KTM is still working fine with the original. I may dump the overflow tank on my 07GG and chage to the stat. They work.

 

[Bobt250]

I don't think my 2003 KTM had one but I could be mistaken.

 

[Berkyboy]

Here's a question for you engineer types.

With the addition of the thermostat this year, and the deletion of the expansion tank, GasGas has gone from a 1.2 radiator cap to a 1.8, does that seem like a little extreme?

For years we got by upgrading to a 1.4 radiator cap if we wanted to eleminate the expansion tank, which was located on the steering head behind the headlight and also inhibitated the proper mounting of a WER steering damper.

If we thought that wasn't enougnh we would also add a pair of "in-line radiator coolers" to help further lower operating temperatures if a bike was prone to overheating.

The 1.4 cap was stock for the GG 4-strokes and seemed to work just fine it just seems that going to a 1.8 is making a big leap.

 

[twowheels]

Here's a question for you engineer types.

With the addition of the thermostat this year, and the deletion of the expansion tank, GasGas has gone from a 1.2 radiator cap to a 1.8, does that seem like a little extreme?

For years we got by upgrading to a 1.4 radiator cap if we wanted to eleminate the expansion tank, which was located on the steering head behind the headlight and also inhibitated the proper mounting of a WER steering damper.

If we thought that wasn't enougnh we would also add a pair of "in-line radiator coolers" to help further lower operating temperatures if a bike was prone to overheating.

The 1.4 cap was stock for the GG 4-strokes and seemed to work just fine it just seems that going to a 1.8 is making a big leap.

There should be no issue with the higher pressure cap - 1.8 bar is only ~26 psi. I had a radiator from a 1.2 bar (~18psi) system repaired and Myler's pressure tested it to over 40 psi. I'm not sure what the 2010 and prior expansion bottle is rated at (at temperature) but dropping the bottle for a simple cross-over and adding the thermostat equipped hose with the higher rated cap sounds like a winner.

 

[Troy F collins]

I have done the math and you would need to have coolant temps over 270 deg to boil it with a 1.8 bar cap.....

I suspect GG was trying to eliminate any boil over out the overflow altogether...thus allowing them to eliminate the catch tank

the idea being coolant should never leave the system in this eco friendly world

but I am no expert

 

[Berkyboy]

Troy

I think you might be close with the "Eco friendly" concept.

Most likely the 1.8 threshold and the elimination of the catch tank may only be related to a new "Eco friendly" standard and nothing to due with improving the cooling system.

 

[skid jackson]

one less part to buy and no tank and tubing to deal with and install during manuf. over many bikes equals a little more jingle in the factory's pocket ...

 

[gasgasman]

thus allowing them to eliminate the catch tank

The " catch tank" is not really for overflow. It is a place for expanded coolant to collect.
My '07 MC 250 did not come with the expansion tank, so I run my coolant level a little lower to allow for fluid expansion.

A catch tank is vented to the atmosphere.

The higher pressure radiator cap raises the boiling point of the coolant. So, you have a lower chance of boiling the bike over.

 

[Troy F collins]

The " catch tank" is not really for overflow. It is a place for expanded coolant to collect.
My '07 MC 250 did not come with the expansion tank, so I run my coolant level a little lower to allow for fluid expansion.

A catch tank is vented to the atmosphere.

The higher pressure radiator cap raises the boiling point of the coolant. So, you have a lower chance of boiling the bike over.

thats exactly what I said in my post

edit the difference in the terminology catch vs expanded I understand

 

[GMP]

For those with a Trailtech, it would be interesting to measure the temp under a good load like a hillclimb or tight sand woods, and then do it again with the thermostat removed. It will depend on what is the flow limitation in the system(impeller, plumbing, thermostat, etc), and be more of a factor at higher RPM (pump speed/flow). I can see the point for winter riding but in summer I'd yank it, one more thing to go wrong even if a slim chance. I pulled them from my KTMs as pumpkins are a lot more boil prone than any GG.

Will it be left in the WEC factory bikes? That should answer the question.

 

[Troy F collins]

For those with a Trailtech, it would be interesting to measure the temp under a good load like a hillclimb or tight sand woods, and then do it again with the thermostat removed. It will depend on what is the flow limitation in the system(impeller, plumbing, thermostat, etc), and be more of a factor at higher RPM (pump speed/flow). I can see the point for winter riding but in summer I'd yank it, one more thing to go wrong even if a slim chance. I pulled them from my KTMs as pumpkins are a lot more boil prone than any GG.

Will it be left in the WEC factory bikes? That should answer the question.

I think your right....I would be surprised to see it on a WEC bike

but would hazard to guess it allows safe operation in cooler temps...particularly those that like to pin the engine with zero warm up time

 

[twowheels]

Coolant Flow

Anybody got a good take on the coolant flow pattern? Does the fluid cool the jug or the head first (ie up or down flow)?

 

[GMP]

Each rad feeds the pump intake separate, the left one through a passage in the cases. Pump output is again through the cases, up into the cyl, head, and splits at the "T" to feed the top of each rad separate. So what the tstat does is just regulate flow through one rad.

This system has always worked very well, especially in slow, tough conditions that produce steaming pumpkins. Also, I have seen a friend crush one rad (leaking), and just block off the hoses on the trail to get back, running on one rad.

 

[Moto7man]

232 F Acceptable Temperature?

This last weekend I raced a SORCS race at Sewanee TN, it was a great event, packed with spectators and riders. I was racing my 2011 EC 300 and I have a Trailtech Voyager with the red temperature light set at 200 degrees Fahrenheit. The ambient air temperature was around 100 degrees Fahrenheit.

It seems that certain things kinda change about your bike at race pace. This was a woods race with some slow tight sections, the highest temperature indicated on the voyager was 232 degrees, and when I got into an open section, the temperature immediately dropped to 219 then 200 degrees quickly. I never boiled over and at the end of the race the coolant level was at the top of the radiator.

I had not seen this thread about the 1.8 bar cap, indicating no boil overs should occur until 270 degrees Fahrenheit.The bike never got and never gets anywhere close to 270, the highest temperature ever is the 232 mentioned above. I am considering racing the Tennessee Knockout next weekend. Should the gasser be ok in these temperatures or should I install a radiator fan before the race next week?

 

[Moto7man]

Buuummmp.......

 

[john r b]

When in doubt. Or try an aftermarket coolant