My 99 tundra2 blew a piston ring and scored the cylinder....what are my options these days? Are replacement motors/parts available anymore....is it something I can rebuild myself?
Thanks

Get it bored. Get oversized piston and rings. Throw away automatic oil system.

From what I see the cylinder is not available but the piston and rings are. Start calling snowmobile salvage yards for part number 420913218. You need to fix the lean condition that caused the issue most likely due to aging crankcase seals, cracked carb boot or carb not cleaned correctly. Not difficult if you are reasonably handy.

Not sure how available parts are anymore.I had one of those motors re built about a decade ago,cant be too difficult there are about half a dozen guys in town here that tinker with small engines that will do that for a few bucks.

Whatever you, don't listen to me.

Just recently I found an outfit that sells new pistons and rings for the 277. Racking my brain to remember where I saw it, but they are out there.

"Ski-Doo Tundra II/LT/R, 250 & 277 cc, 1985-2005, .020 over Piston
Brand New
$39.99
Buy It Now
+$6.99 shipping
Returns accepted"

EBAY

I agree with Dirt..........especially the part about ..."throw the automatic oil system away" !!

Rebuildable. Had a couple done, last one 2 years ago and it cost me 250. Like Dirt said bore and upsized piston. Mix fuel rich on break in like 40:1. Good to keep an eye crank seals too. I pushed it too far once and got an unplanned hike out of it

Had two pto seals start leaking. The machine runs rich. Two walks due to this. It warmed up outside too much. Got too rich to start and run slowly. Changing crank seals is a biatch because you have to make a puller to separate crank case. Ironically, I made mine out of a Bravo motor mount.

It was odd,I had been mixing gas for mine for a couple years before it needed the new piston.
Never had a problem with the oil injector before I went to the premix.

Some go for years with the pump on and no problem. Some don’t. I had planned to pull the oil pump off one of mine after I got it to camp. Halfway there (a 2 day trip) I discovered it hanging on by only 1 loose bolt. Single cylinder vibration. Many have burned up when plastic drive gear fails

I had a 2000 and an 2008, both bought new. Ran them for years, had a ton of miles on both of them (the 2000 was my 'extra' machine after I bought the 08). Had the oiler quit on both of them and siezed them both up the same week 2016. It was -20 that week and my theory is that the oil gets thicker in those colder temps and the plastic drive gear gets brittle with age and the thicker oil caused them to break. I do know that quite a few people would have the screws that mount the oilers (just screwed into plastic) strip out or come loose. You have to remove it every time you work on the pull start and if you aren't careful you can overtighten those screws into the plastic and strip them.

The 08 I bored and put an oversized piston in like Dirt recommends, the 00 I just poured a bunch of oil in the gas (pulling the hose off the bottom of the oil tank to drain oil into a bottle on the trail can get messy) and after it cooled down it was fine. Make sure and replace the crank seals, if you don't you are liable to be rebuilding it again shortly... that is the voice of experience.

After that I always mixed my gas until I bought a four stroke. Personally I never bothered with removing the automatic oil system, I just disconnected the cable and left it in place, it wasn't bothering anything.

I have had my 550 tundra scandik since it was new in 08 and have never used premix.like i did in the one lungers.
Still use the mineral oil injector.Runs like new.I keep it maintained This year I had some bearings changed,new battery installed and new voltage regulator and slidersTwo years ago new carb boots.got to keep an eye on those they crack after a while.I think that was the second time for that.On the old elan they always cracked on the top,I would take it off wrap it with duct tape and put it back on upside down-good for a couple more years lol.
I change out the chaincase oil every year also.They say just top it up but I like to change it out.
Snowmachines seem to always run much better in the cold than they do when it is mild,especially the two stroke fan cooled.

You could leave the oiler on, but i would verify its operation. Use premix for 5 gallons. Mark oil level on tank with marker. Run machine around and burn most of that fuel. Top fuel and oil tanks to previous levels reccording volumes used. Calculate mix ratio oiler is doing. Should be arould 50 to 1 or 2.6 oz oil per gallon of gas.


Oilers are just another thing to break. How do you know when they break?

When they stop smoking the oiler is not working,
I always top up the oil reservoir when I gas up.
I have had lots of stuff break and need replacing on the 550,but never the oil injector.
A liter of mixing oil under the seat to dump in the tank will get you home if the machine stops smoking out in the bush.
Like I said I did use premix on the tundra cause I knew they were known to fail,did not stop the piston from needing replaced.

The biggest issue with oilers is that they only break when the engine is running ! How much worse could it be ??


Another benefit of disabling the oiler is that if you clean out the oil reservoir and cut out the top ....it makes a handy and warm place to stash some dry, warm gloves.

Be sure to plug off the oil inlet on the carb or it will suck air