formula 500 mileage...help - Snowmobile Forum: Your #1 Snowmobile Forum

camo500 · 02-16-2004, 08:25 PM

I just picked up a 97' formula 500. It runs great for most of the day...but then starts sputtering and blatting. If I change the plugs it goes like hell again. I have been running br9es plugs because that is what the former owner had in it. Are these the right plugs. Also the mileage is terrible on this thing. My buddy 01mxz800 and I ran 50 miles and we both fueled at the start of the day. When we topped off our tanks....my gauge was showing empty.We both fueled and he put 7.85 in his 800...and I put in 13.50 in my little 500. Is it just me or does this seem really horrible mileage.My old 91 polaris 650 never fouled a plug and I could get right around 100 miles on a tank. Any suggestions would be appreciated.

RoloCade · 02-17-2004, 02:03 AM

Runnin way too rich it seems. Have the carbs redone and set the air fuel screws to where they should be. I ran the 9es plugs when i should run the 10s and fouled them cause of it runnin too rich. The 9 plugs run hotter than the 10 and if you foul them then you need to do the carbs, expecially with that milage.

**smallengineguy** · 02-17-2004, 08:24 AM

Yup, Jetted too rich. You need to change the jets to the next smaller size.

01MXZ500f · 02-17-2004, 02:52 PM

my dads got the same sled he has had no problems with it, i have to agree with the rest of them it sounds to me like it is running rich, or your plug connection my not be sparking enough...

snomobeelridur · 02-17-2004, 08:27 PM

how much do u weigh? anything over 140 lbs really sucks the gas out of those 500s.