So, I live in a remote part of Canada and have a 550f. I've had 550s before but it seems some folks round here have found that these motors blow a piston and seize up. Some speculation is from running different 2 stroke oils, some figure it's carb adjustments. Who knows. Anyone with experience on oils? My old 550 would burn any old oil I put in it and never complain. My thought was the EPA regs tuned carbs too lean. Thoughts?

Always tune you carbs with the right jets and go by spark plug color......yes they will run on just about any 2 stroke oil.

 

I'm not a mechanic, but my understanding in Yellowknife is, the "recent" 550 Fan motors are jetted lean from BRP for emission reasons, some folks running in deep cold here have had failures very early on. My slobbering 09 is original with over 13,000 km's with nothing but Amsoil Interceptor oil since new.

 

cheapest you can find.. and throw a little in the tank. the older 550s are known to go lean from carb boots, and also the oil pump failure will ruin your day. That's what i've found anywho.

 

Thanks, yeah. Cheapest I can find was always my method for my old 550f. Also I suspect the same regarding the lean mixture. So how do you resolve that?

PS half a bottle in the tank when I filled up was my old method too. Big puffs of smoke was a good sight.

 

New oil pumps might better but some of the old ones would not reliably pump oil at -40. Used to premix and leave the oil tank empty back when I was motivated enough to ride at -40.

 

If you live far up north, check that your 2 stroke oil will pour at the temps you ride in. The synthetic skidoo stuff is way better in my opinion as it pours at lower temps. And as pointed out earlier, if your carb boots are cracked and leaking air, you will run lean and have premature engine failure. Plug electrode colour is your best check.

 

Check and see what jets are in it stock.

Is that the VM30 carbs? Should be 190/200 for the main jets. Might go 200/210 if you think it is lean. No danger in going up in sizes.

 

I have an 05 SWT 550f and I am a believer in what the factory recommends for injection oil. I have always run the Bombardier 2 stroke mineral oil and I did "smoke" a piston, but not bad enough to seize it. I found that it was running to lean due to bad carb boots so I replaced them, new std. pistons & rings into re-honed cylinders and went 1 size richer on the carb needle. Has been working fine since

 

I had a 550 tundra that i used at temps down to -40 when on the trapline. Any colder i stay inside.
A little trick to keep from leaning out is to slip the cold air intake off the airbox, now its pulling in warm air from the motor and no chance of leaning out.
I ran cheap mineral oil and never touched the motor, it had 9500kms and compression was still almost as good as new, dropped 5 psi.
As well it had very many idling hrs with trapping and the work i did for forestry, it would run all day and drive 100 kms during that time.
I wished the 550 had an hr meter.

 

A good tip about the airbox. I have covered the hood with canvas or tarp to restrict cold airflow. But yeah, I've quit the minus 40 rides now, except maybe to get a load of wood.

A friend has 16k on his 550 in a 2014 skandic and has used various oils. I think it's generally the extreme cold that causes these motors to lean out and seize.

 

Leaning is always what kills them............