Motor down in out 2016 Axys

[HECKS]

My trusty steed finally gave up a few weekends ago, and curious of ones opinion on how things came to this. History on this unit is that it has been the best Polaris I have owned.
Started mountaing riding in 2009, and have only owned Polaris'.
Did the original topend at 200 hrs 3100 miles, as leakdown dropped to 6-7% on PTO side, MAG was 2-3% still. Was suprised it was solid numbers until this point. Fresh top end lasted 20 hrs, as I broke a wristpin clip that went through the piston/cylinder on the MAG side. Replaced cylinders and new piston kit installed last fall. This season she made 6 days of riding, until she seized up at the end of March. Was in a bad spot tree riding, so I worked the clutch free with my shovel handle while putting oil into the cylinders for approx and hour. Got it running and made it back out 2-3 miles to a trail that was able to tow it home from, seized solid at this spot. 4400 miles, all mountain. Have the engine torn down and PTO bearing must have been going as it got hot !, The 2 oil lines going to the PTO side were melted off their spigots. PTO bearing inner cage melted away, and crank lobe worked itself off it's pin and into the case and away from con rod. Now, it's looking like she needs a new long block. Anyone ever seen a crank porkchop come off its pin like this ?

 

[Teth-Air]

That is kind-of an ugly one. Hard to say where the problem started but it looks like everything got destroyed. I would be very worried about adequate oiling with a new shortblock and reusing the very same oiling system without 100% confirming it is working properly.

 

[HECKS]

I'm going to check those line for blockage, but all other were working, as MAG side has lots of oil in it. Not to familiar with these pumps, but I'll need to check it out

 

[NEWDUCK]

From my understanding its pretty common to have the pto walk off. It takes all the abuse. Crank rebuilders usually weld them when reassembled for that reason. That crank end definitely took a beating!

 

[Teth-Air]

From my understanding its pretty common to have the pto walk off. It takes all the abuse. Crank rebuilders usually weld them when reassembled for that reason. That crank end definitely took a beating!

If that happened first and came into contact with the cases it would generate lots of heat and debris to damage the bearing. And then everything else.

 

[HECKS]

Makes sense. Most of the crank damage is just magnesium which can be scrapped off, looks worse than it is. Wish it would have shown its face when I measured con rod play on its last rebuild.
Pre Trip I had just rebuilt the primary, balanced it, and installed Indy Dans weighted clutch cover to help be 'nice' to this engine lol.
And as luck would have it, I ripped my PC track off the day before it seized. Spent the night swapping tracks off a buddies broken down 17'. Great way to end my season off !

 

[Teth-Air]

Did it way over rev when the track ripped off?

 

[Teth-Air]

Now I see the track did not come all the way off.

 

[HECKS]

No overevving. The trail ride up to the cabin, fixing another Axys on the way up and I noticed a lug was missing and delamenated the belt. Took it easy to the cabin, and felt it tear into the first window. Haywired it together to limp down, and made it a few hundred yards and spooled it up in the tunnel, tore halfway across and had to saw it off. 2nd track this unit has been cut off

 

[BeartoothBaron]

Wow, that is a crummy way to end the season! The PTO working its way off is something associated with too wide belt side-clearance; lots of reports of sleds coming from the factory with .050 and sometimes more (should be .010-.020). That causes a slide-hammer effect at engagement and damages the crank and bearings over time. Not saying that's to blame here: 4400 mountain miles is definitely past the point where you'd say you got your money's worth, and it may be more "normal" wear and tear. Obviously, you'd want to be careful of re-using anything unless it checks out, but that case and crank are probably salvageable.

If it were me, I'd send it to Indy Specialties; would be around $4k for a built long rod with a 2-year warranty. Might be a lot of money, but if the rest of the sled is solid, it's not a bad deal. On the other hand, if the chassis has some tweaks and it could use other work, it might be time to move on. If it were three years ago when you could find holdover AXYS sleds for close to $10k, or a good used one for <$5k, I think we'd all be saying "part it out and move on," but it's tough to say what the best value is now! If you fix it, you'd definitely want to clean or replace injectors, check out the oil pump, and all that stuff to make sure there's no lingering demons that'd hurt the new motor.

 

[HECKS]

Thanks BTB, My belt clearence has been set at 15 thou for quite a few years now, secondary been lined up with TRS' tool, but the damage has been done.
Being in Canada the Indy Dan route is a bit pricey with our dollar. I have found a few new long blocks for a decent price. I'll replace all jackshaft/drive shaft bearings.
Chassis is in great shape, and have it setup to my liking with 36" arms, mulitple shim stack changes, and cut tunnel. Going to flow test the injectors and test the oil injection.
I would honestly like to see one of my sleds make 10,000 km on the odometer, all mountain riding. 3000 km to go and a few dollars to get there lol.
In this sleds life, it has never blown a belt. Worn a few out but it has been great. It's on it's 3rd set of skis, 3rd set of hifaxs, Soon to be 3rd track, 3rd set of motor mounts, 2nd set of side boards, 3rd primary rebuild, original secondary - only spring changes.
I owe it to this girl to keep her together

 

[Teth-Air]

Where in Canada are you located? Recreation Supply has motor sources so I would try them. CV Tech I believe they are an agent for.

 

[HECKS]

Hi Chris, I am out of Sylvan Lake. BWC east of Edmonton has a fair selection as well.
I have actually meet you a few times at the sledshows, we use to sell BCA and Snobunje stuff for a few years as SledWrecks.

 

[Teth-Air]

Hi Chris, I am out of Sylvan Lake. BWC east of Edmonton has a fair selection as well.
I have actually meet you a few times at the sledshows, we use to sell BCA and Snobunje stuff for a few years as SledWrecks.

Okay, yes I remember. I am glad you know where to get one. I know BWC buys good running sleds to wreck but if you want to keep it for a while it might be best to start with a new or remanufactured block.

 

[HECKS]

Supposedly BWC has 2 crate engines on hand. We will see !
Might have to take the crank out of the new one, and have the counter weight tacked up onto the pin.

 

[Rustle]

I had this EXACT same failure. Same oil lines popped off. From the looks of the engine compartment in my sled the oil lines had been off for a while; there was a fine film of oil and dirt on mostly everything. Based on your pictures and dirty oil film at the bottom your engine bay I'd say the oil lines coming off was the cause of your failure not a symptom. They popped off so the PTO bearing and PTO cylinder weren't getting any oil thus causing your failure, same as mine.

 

[HECKS]

Crazy ! Both of mine melted off though, so that makes me believe the bearing was going, or the crank walked off into the case to start it all off.
Were your line popped off or melted ?

 

[volcano buster]

There was mention of a slide hammer effect on the clutch causing the crank to shift on the pin. Is this step one, then bearing gets hot and melts hose off. Once off, remaining parts and bearings are on a short fuse?

 

[HECKS]

There was mention of a slide hammer effect on the clutch causing the crank to shift on the pin. Is this step one, then bearing gets hot and melts hose off. Once off, remaining parts and bearings are on a short fuse?

Thats how I have came to understand this failure.

 

[volcano buster]

What clutching parts are in your primary and what engagement rpm were you seeing?