2010 450 Cold Weather


34 replies to this topic
  • Bambislayer

Posted January 19, 2010 - 10:14 AM

#21

i suspect there is a general ambient temp range where the bike would be "warmed up" in almost any type of riding. I say this because while high rpm use will generate more heat, the resultant high speeds in cold air temps would also generate more cooling. i dont have cold enough weather or enough time to experiment with it but i figured the guy who has been taping up his rads would probably be able to offer an experienced data point.

  • ProMed

Posted January 19, 2010 - 04:07 PM

#22

Cold engine operation requires richer than normal mixture. Very cold engine operation requires much richer than normal mixture. With a carb, you have only two modes of operation:cold start, and normal. Ordinarily, you use the choke to start the bike, but you switch it off as soon as possible, which moves you to whatever your hot engine jetting is, even if it's a little lean for the weather.

EFI doesn't do that. Once you switch out of the cold start mode, it "rejets" itself for the temperature, base on ambient air and coolant temps, and will be running quite a lot richer in freezing weather than a carb jetted for the 50's or 60's.

Any engine will push fuel into the oil on a cold start. The amount of fuel that would remain in the oil in a cold started engine that was shut down in two to five minutes would amaze you. If you doubt that, send in a used oil sample after doing that sometime and see what the results say. Under normal conditions, the fuel simply evaporates out of the oil and leaves via the breather tube. The few elements of gasoline that are not volatile enough to evaporate at 150-160 degrees are absorbed by the detergent package.

The trouble here appears to stem from the fact that the bike has no thermostat, which causes the coolant to be over-cooled, and the EFI is responding as programmed to the low coolant temperature, thinking that the engine is in it's warm up phase. This allows it to deliver a mixture rich enough to push fuel past the rings, even while "warmed up".

Note that SNO-PRO reports no more oil in the fuel after blocking the air to the radiators.

Great info, thanks!

  • CaptainKnobby

Posted January 19, 2010 - 05:44 PM

#23

I guess at cold temps you wouldnt have to worry about it sitting and idleing for longer than 5 minutes and the glowing header.:banghead:

  • SNO-PRO

Posted January 20, 2010 - 06:23 AM

#24

"Bambislayer" while moto riding this bike I saw no fuel dilution at 50 degrees. Ice riding is a whole different animal as we see 0-40f while riding from tight hairpin corners to 5th gear WOT straightaways and obviusly see max cooling in those conditions

  • Bambislayer

Posted January 20, 2010 - 07:07 AM

#25

good to know. thanks. i wonder if there would be any dilution from say 32 to 50? from your info it would seem highly unlikely.

  • CaptainKnobby

Posted January 20, 2010 - 07:46 AM

#26

I would say you would not have to worry about fuel getting the oil when riding at 32 degrees or higher. Just when riding in extreme cold weather say like 30 degrees and lower.

Its the cold air that flows through the fins of the rad that permits the water from getting warmer. I'd sat riding at 20 degrees would make the windchill factor like 10 degrees which would make fire not warm up:smirk:

  • Gunner354

Posted January 20, 2010 - 08:33 AM

#27

Sounds like a thermostat should be a factory item. KTM 300 had one stock.

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  • saccityfire

Posted March 09, 2010 - 01:57 PM

#28

I'd sat riding at 20 degrees would make the windchill factor like 10 degrees which would make fire not warm up:smirk:


There is no wind chill factor on anything except flesh. Wind chill factor is the "perceived" temperature below ambient by our nervous system.

Therefore, if it's 20 degrees outside, it's 20 degrees no matter how fast the wind is blowing or you are riding.

The amount of cooling taking place between the hot parts and the air is affected however by how fast the air that becomes heated near the hot part is replaced by air that is at the ambient temperature. The faster you are going the faster the ambient temp air moves through the radiators and over the surfaces of the engine.

Sorry, couldn't help it after seeing the "wind chill" comment.

:banana:

  • grayracer513

Posted March 09, 2010 - 02:03 PM

#29

So then, the radiators work the same whether air flows over them or not? :banana:

("Wind chill" is the wrong term for this, nevertheless)

  • Bambislayer

Posted March 10, 2010 - 06:24 AM

#30

There is no wind chill factor on anything except flesh. Wind chill factor is the "perceived" temperature below ambient by our nervous system.

Therefore, if it's 20 degrees outside, it's 20 degrees no matter how fast the wind is blowing or you are riding.

The amount of cooling taking place between the hot parts and the air is affected however by how fast the air that becomes heated near the hot part is replaced by air that is at the ambient temperature. The faster you are going the faster the ambient temp air moves through the radiators and over the surfaces of the engine.

Sorry, couldn't help it after seeing the "wind chill" comment.

:banana:


That is sort of correct.

When stationary and turned off it is 100% correct. A piece of metal on your bike while it is parked will adjust its temp to ambient regardless of wind speed.

The reason wind chill primarily affects only living creatures is because of heat loss. The higher the wind speed, the faster heat loss occurs for a given temp. Wind will definitely affect the temp of your engine in a motorcycle being ridden due to the same principle. The radiators are to designed to allow heat loss to occur. That is how the system works. The faster you go for a given temp the better the heat dissipation or heat loss so wind chill may not be the correct terminology but while moving, the wind most assuredly has a cooling affect on the bike the faster you go. That is how the radiators work.

  • grayracer513

Posted March 10, 2010 - 08:15 AM

#31

Machinery won't get any colder in the wind, but it will get cold faster. That was my point.

  • Bambislayer

Posted March 10, 2010 - 10:49 AM

#32

Machinery won't get any colder in the wind, but it will get cold faster. That was my point.


Because of the speed at which heat is dissipated, it also wont get up to temp as quickly or at all in certain temps.

That is THE point!

  • grayracer513

Posted March 10, 2010 - 11:03 AM

#33

...it also wont get up to temp as quickly or at all in certain temps.

That is THE point!

Precisely. One of the downsides of having no thermostat in the system. Whereas a carb just runs lean because of the low temps, EFI compensates based on its programming.

The problem is that the coolant temp has less to do with fuel vaporization and behavior than the temperature of the intake tract and combustion chamber, which can be warm enough to run without too much additional enrichment even while the coolant temp is low. But there isn't a sensor for that, so the system can't know about it.

  • saccityfire

Posted March 10, 2010 - 09:55 PM

#34

My point was not kind of correct. It was entirely correct. The comment was in regards to the use of the term "wind chill factor" which is the "perceived" temperature as being some point below ambient by the nervous system of a human.

If a piece of metal, or radiator or whatever is left anywhere, it will reach ambient temperature. If the ambient temp is 20 degrees, the thing will reach 20 degrees and not a tiny bit lower even though the wind may be blowing 100 miles per hour and the wind chill factor may be -50 degrees. :banana:

I agree that if the wind is blowing through the radiators of a running, stationary bike, the bike will cool faster as this is removing the air heated above ambient via radiation from the fins by conduction to the constantly replaced ambient temperature air of the wind. :lol:

However Gray, you stated without qualification "Machinery won't get any colder in the wind, but it will get cold faster." This statement is correct if the bike is sitting still or moving into the wind. However, If you are traveling with the wind, the bike will actually run hotter than if no wind were present. This of course is due to the stagnant air pocket that you're traveling in causing a reduction in airflow over the radiator fins. In fact if you travel the same speed and direction as the wind there will be almost no airflow over the fins and your cooling would become nearly 100% radiant. The only conduction would be from the heated air rising and pulling an ambient temp airstream up from below. You might just overheat on this windy day! :banana:

:banana:

  • saccityfire

Posted March 10, 2010 - 10:06 PM

#35

It's like a disease. I just can't help myself!

I think this winter weather is getting to me. I need to go riding.





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