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Discussion Starter #1
just like the title says every winter i lose fuel econemy, Torque and top end every winter i never paid to much attention to it untill i seen another post about it but every spring im amazed at how much power i get back. i finally figured it out to be winter when i was working on it in the shop for a few days when i fired it up it had tons more power left it outside over night, gone. this winter id like to find a fix itll only accel to about 40 on flat ground, 30 with slight uphill. it accelerates slow, i did the white primary spring mod and was very noticable when i pulled it out of shop, now theres barely a noticably difference except higher rpms. my fuel mileage is cut in half at best.

things that have been done to it in last month
valves and timing done
all electrical problems fixed, purrs like a kitten now
white primary spring

only thing i noticed if i run all my lights and handwarmers i can only get up to 5000rpm with lows on its fine right up to about 6200-6400, gonna run a new power wire for acc today but i doubt thats causing this since its happend for years
 

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Usually winter blends of fuel, and the fuel itself shrinking due to the cold are the culprits of diminished fuel efficiency. I cannot say that I lose power in winter though. My machine runs great in the cold with zero electrical issues. I was certain that fuel injection was best in adverse conditions and this has so far proved correct. Christmas day and Boxing Day were the only two days where I noticed my machine any thirstier than normal, but I was following snowmobiles through farm land chewing through virgin* snow. (*fresh snow, no pee in it)

As far as your handwarmer issue goes, I am puzzled by that. I have run with high beams and all warmers on and have not suffered power loss.
 

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Discussion Starter #3
ive got 5 lights and i think it over does it
 

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The white spring is stiffer than stock all the way through so that will bump up rpm and any given speed. Higher rpm will cut fuel mileage a little. The power loss is mostly winter blend fuel.
 

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just like the title says every winter i lose fuel econemy, Torque and top end every winter i never paid to much attention to it untill i seen another post about it but every spring im amazed at how much power i get back. i finally figured it out to be winter when i was working on it in the shop for a few days when i fired it up it had tons more power left it outside over night, gone. this winter id like to find a fix itll only accel to about 40 on flat ground, 30 with slight uphill. it accelerates slow, i did the white primary spring mod and was very noticable when i pulled it out of shop, now theres barely a noticably difference except higher rpms. my fuel mileage is cut in half at best.

things that have been done to it in last month
valves and timing done
all electrical problems fixed, purrs like a kitten now
white primary spring

only thing i noticed if i run all my lights and handwarmers i can only get up to 5000rpm with lows on its fine right up to about 6200-6400, gonna run a new power wire for acc today but i doubt thats causing this since its happend for years
Cold winter air is very dense, so your bike adds more fuel to keep the mixture right, thus some of the loss of mpg. Add in the winter blends and there is the rest of your loss. I have no idea why it's not running as good. Usually winter air will make the engine run a little lean and lean is fast, ask any racer. My vehicles have all run at least as good in winter, as in the other seasons
 

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Discussion Starter #6
it makes sence to lose some mpg but cold winter air being more dense and it adding more fuel to compensate should in turn give me more power not lessen it. as for the white spring and higher rpm, this isnt new, my bike has done this since i bought it brand new in 2010 and its running fine purrs like a kitten just feel a loss of power, im going to raise my tire pressure because i check it before a big ride(in summer time) and make sure its at 6.5-7psi ive never checked it durring winter just a boot check to make sure there not flat and have never been. i think this lower psi could have a little to do with it but theres gotta be more to it
 

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Cold winter air is very dense, so your bike adds more fuel to keep the mixture right, thus some of the loss of mpg. Add in the winter blends and there is the rest of your loss. I have no idea why it's not running as good. Usually winter air will make the engine run a little lean and lean is fast, ask any racer. My vehicles have all run at least as good in winter, as in the other seasons
This is my first winter with a quad and What I noticed is when the weather got colder (first noticed during deer hunting season) my quad was idling higher than in the summer. I went for a rip down the trail and when I stopped at the end to turn around my idle rpms were high 1400's. Could this be caused by the quad wanting more fuel cause of the denser air. I have lowered the idle since.

Sent from my SGH-I337M using Tapatalk
 

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I am awaiting a tool to adjust the air/fuel one the 2000 325 we just put rings, rod bearing and rebuilt the carb on. It is loading up so bad currently but for the heck I started it tonight with temps just a few degrees below freezing. Started fine and idled about 2000 however. The dense air help solve the running rich issue somewhat. :)

Most that drive cars and trucks know they get lower mileage in the cold weather too.

Dense air is good but lubricant becoming semi solids is not good.
 

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Cold winter air is very dense, so your bike adds more fuel to keep the mixture right, thus some of the loss of mpg. Add in the winter blends and there is the rest of your loss. I have no idea why it's not running as good. Usually winter air will make the engine run a little lean and lean is fast, ask any racer. My vehicles have all run at least as good in winter, as in the other seasons
This is my first winter with a quad and What I noticed is when the weather got colder (first noticed during deer hunting season) my quad was idling higher than in the summer. I went for a rip down the trail and when I stopped at the end to turn around my idle rpms were high 1400's. Could this be caused by the quad wanting more fuel cause of the denser air. I have lowered the idle since.

Sent from my SGH-I337M using Tapatalk

I'm not positive if the denser air would increase your idle rpm. It might since your bike is carbed like mine, I don't think a carb has the capability to adjust the idle circuit like an efi bike should, which would make it lean at idle and idle at a slightly higher rpm. I'm sure someone will correct me if this is wrong
 

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Ours currently wants to load up when temps are 70 but at 27F tonight it idled very fast and did not load up and the only known difference was air temps that I know about. It was getting the same volume of air but it was just more dense.
 

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Ours currently wants to load up when temps are 70 but at 27F tonight it idled very fast and did not load up and the only known difference was air temps that I know about. It was getting the same volume of air but it was just more dense.
That sounds about right since denser air has more oxygen molecules and therefore turned your rich condition into a slightly lean condition
 

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Mine seems to run the same in winter or summer or at least I can't tell a difference. Based on mountain driving or flying the higher you go the less power your engine can produce as the air is less dense. Same with an airplane, the less dense the air (up high) the less power the engine can produce so you have to adjust the fuel mixture to compensate which means leaning the fuel, not adding more. I would guess with winter air being denser than summer it would have a very similar effect and you should produce more HP in the winter. Air density should work in your favor in the winter from a power standpoint. The other winter factors (oil viscosity at start up, longer warm ups, pushing snow, using low and so forth) have a big impact on fuel economy but who cares....not much more fun than pushing snow with my ATV. I end up plowing out my entire neighborhood...
 

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Discussion Starter #13
carbed bikes should have an fuel adjust screw witch adds or lessens the fuel to you pilot if you go out to far then you have to up your pilot if you go in to far you have to lower your pilot
 

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Most of the time you should not have to make any adjustments to a carb because of the Temperature (except maybe in very extreme cases). Altitude is your biggest issue. If you buy an ATV in Indiana (Altitude 800 Ft.) and then plan on riding at 8500 feet you will probably have to re-jet the carb for higher elevation (smaller jet, leaner) which is where EFI shines as it for lack of a better term "re-jets" (adjusts the fuel:air mixture) for all conditions. I noticed on my carburated Honda Rancher that even in the smoky mountains I lost more and more power the higher I went. When I switched to the Rancher 420 EFI it didn't seem to have much of a power difference at sea level or 4000 ft. (dog at both altitudes, lol). The 850 is just amazing no matter the altitude or temperature. Will be pushing snow at 15 degrees F tonight and it won't care how deep or cold it is but I think I might wear a coat as I run for sh!t at 15 degrees. There are a couple of companies out there that sell carb kits that allow you to adjust for altitude by simply turning a thumbscrew but they are kinda salty. Somehow it adjusts the main jetting of the carburator. I rode my 1300 VTX up to Klingman's dome and it ran ok but you could tell a big difference in power at 6000 feet. All future vehicles will have EFI just incase I want to ride out west.
 
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