[brad@cs.utoronto.ca]

How do you guys setup your engines for cold weather flying. Has anyone found they had to reset the main jet to compensate for more dense cooler air?

I'm still new to setting up my engine(582) for different types of weather. I was running fine in the 20-30C range and am just a bit hot on the egt now that the cooler weather has come.

[Trev Page]

You generally will need to re-jet a 2-stroke colder air. Usually you will have to drop the main jet a size or two but here's a chart that will help you calculate the proper jet to use for temperatures and field height:

[Matthew Roung]

Brad, you could try lowering the needle clip a position or two (raising the needle). This will richen the mixture, and bring the egt's down, mostly in midrange (cruise). If at full throttle you are still good on your egt's, then there is no reason to change the main jet.
-Matt

[Trev Page]

Matt is right. A Bing 54 carb has 3 mixture settings : idle, needle-jet and main jet. Each affects a different RPM range. Do the needle jet first as this is the main one used during flight and cruise.

[shorty]

Lower your needle clip on each carb one notch at a time.
watch your egts drop.
If you can adjust your prop that will affect your EGT;s as well.
It trial and error but also cross check your plugs to make sure your egt is reading correctly. Trust your plugs.
Also always make sure you warn up propelry before full throttle.
582 can take 5 to 10 mins to warm up. Watch your coolant temp gauge go to 140 F and pull back to 125F then up again to 140 F . IF will do this as the entire coolant gets heated . You might have to tape off part of your rad. I like to run no lower that 160 F and no higher than 180F but short runs 180 to 190 are ok if not prolonged.

And yes every notch you move that clip on needle will suck 10 to 15% more fuel but you need this to keep egts down in cold air. And you get that much more perforamnce as well.


Enjoy !!


Shorty