I just blew up my viper again, When I rebuilt it last year I turned up the oil pump and moved needle clip one notch richer, on the advice of a local dealer. I heard that colder temps lean out the mixture, any truth to this? or just a myth?
colder temps=leaner. How cold was it?
9801srx
Member
it's true.colder air is denser so it contains more oxygen by volume than warm air.
RIVERRUNNER
Active member
Yes colder temps lean out the fuel to air mixture, but you must be running either to close with your jets or there is something else wrong.......What are you run your carbs at what is your altitude and what are the temps.....is your oil pump to spec...We need more info!!!Post back!!
fleet man
New member
It's a PIA, but I do my jetting and such on cold days. That way I know that I can ride down to that temp. Usually -10 degrees. I don't go out if it is much colder than that. By doing it that way I know I'm good for the warmer days.
The sled is completely stock, I did the fuel pump mod by raising it off the tunnel? It was -20+ This time was across the lake and last time was in a field? Oil pump is set 1mm rich
fleet man said:
Thats what i do to. 
Jetting=Higher number richer????
RIVERRUNNER
Active member
yes...higher the number the richer it is....do you have a manual for your sled?? Are you going to put it back together? If you are, you need to check your plugs and piston wash at idle, 1/4-1/2 throttle and at wot. Like they said above...jet for the absolute coldest your sled will ever see maybe a little colder..I will not run the best in warm weather, but you will not melt it down...Then when you do go out on a really cold day that you are going to be holding it to the bar across a field or lake it is a good idea to check your plugs after 15 min of riding before the wot runs, just to make sure you are safe....just my 2 cents...Good Luck....RR
daman
New member
That would be on your mains,what's your jetting specs???Fireman77 said:
should have went up on the mains too not just needls
Bushman
New member
I am shooting from the hip here but from my Mikuni jet chart I think 20* was worth 1 jet size. If you are jetted for 0 & it drops 20* you would need to go up on size main, If you went up 1 clip richer on the needles you actually needed to lower the clip 1 groove & the you can also do half clip adjustments with the washers. Stock jetting was 147.5's for the mains ?
TJ500
Member
Fireman77 said:
are you by any chance burning ethanol added fuel for the first time?..
redsnake3
New member
stock viper jetting is good down to -50c at sea level.
Bushman
New member
redsnake3 said:
Thanks thats what I was thinking, Sounds like chit fuel or water to me. Is this the same cylinder?
daman
New member
wow,that cold....redsnake3 said:
redsnake3 said:
Who in the world would go out in that temp???????????
Just thinking about it me feel cold
I've been out in -40, which is the same in C and F. You betcha it's cold!
daman
New member
The coldest i've been out was -10F, thats cold enough for me,anymore then that is just crazy..
RIVERRUNNER
Active member
This week I was out in -20 and a windchill of -60.....that makes the srx really rip....LOL good for all kinds of HP...
redsnake3
New member
ive been out in -50c without windchill, never seen anyone out, all the stores arouund where closed due to the weather but i didnt see what all the fuss was about
must be my eskimo blood.
must be my eskimo blood.