2013 Pro 800 gremlins, Help!

[PWDRYETI]

I'm encountering a strange issue with my 2013 pro 800 and am looking for any help or advice from infinite wisdom of veteran sled necks on this forum. It's a saga so to anyone who's reading this I thank you in advance!

Just a lil backstory: a few seasons ago I bought a 2013 pro 800 from a kid who (I now know from the wear on the sled, but didn't know at the time) ran the ever lovin piss outta it. It had 1900 miles on it. The sled ran great for a season and then it stuffed a piston and marred the cylinder.

The next season I paid my small engine guy (I am a novice mechanic) to install a complete new top end kit from Indy specialty in it (jugs, pistons, rings, etc). I ran that for a season with no issues although it was a terrible snow year soI only got it out a few times.

Fast forward to this season: First ride of the year I get a half mile down the trail and it dies on me and is seized up, I can't pull the start cord. I take the plugs out and give it three pulls, put em back and it's starts up but runs like ****. I turn around and take it straight to my mechanic. He tells me one of the power valves was sucking air leaning out one cylinder and starting to burn down the piston so he replaces the power valve, "cleans up" the cylinder and puts in a set of new pistons.

Second ride of the season I get a couple miles down the trail and it does the exact same thing. Mind you I'm not givin er I'm just trail riding. Dies, seizes up, can't pull starter cord, I remove plug and give it a few pulls, put em back, it runs like ****, this time i towed it home cuz i didn't want to risk further damage and return it to my mechanic. This time he tells me he took everything apart and everything looked good, cylinders looked good, etc, with the exception of the reeds being super dirty. So he cleaned them out and put everything back together. Maybe it's worth noting here that my other buddy who's a sled mechanic told me that he's never cleaned reeds, "they're either good or bad" he said.

Third ride of the season, I start her up and she's running like a top, sounds amazing, feels amazing, then same thing: I only got a quarter mile down the trail this time and she dies, seizes up, can't pull starter cord, pull the plugs, fires up with my thumb on the throttle, runs terrible, limp it back home.

So thats the long of the short. Does anybody have any insight into what could be causing this? My mechanic told me the temp sensor was accurate when he tested it. I'm running polaris gold oil. My buddy thought that it kinda seemed like it was hydrolocking but said that's more likely to happen when it's not running. I trust my mechanic, he used to work for Polaris and then started his own shop, but I can tell he's confused by this too. Any insight is greatly appreciated!

 

[RHODESIE]

Was the oil pump ever cranked up? Screw should be almost flush with the jam nut.
The oil cap should have a tiny hole drilled in the bottom side also so the tank can breathe. Those caps don’t always vent properly.

 

[PWDRYETI]

Was the oil pump ever cranked up? Screw should be almost flush with the jam nut.
The oil cap should have a tiny hole drilled in the bottom side also so the tank can breathe. Those caps don’t always vent properly.

I don't know if the oil pump was ever turned up, should or shouldn't it be? If the oil cap wasn't venting proper it would restrict oil right?

 

[ditch1000]

You should turn the oil screw in like posted above and if the oil cap isn’t venting; it’ll put air bubbles in the oil supply line. So it is important to drill a hole in the oil cap or get a doo oil cap from an XM.
Also, confirm the oil lines off the pump are hooked up to the correct port.
I had a 2014 Assault where the mag side cylinder and oil pump gear were swapped and costed me a crank and top end within 100 miles.

 

[Tatlow]

Are you pulling the plugs because it feels like it’s hydro locked? This seems more than just oil cap. Is it one particular cylinder that is going down? Did it idle fine each time? What was the compression on the cylinders after you brought it back in?

 

[hennmann]

Was the oil pump ever cranked up? Screw should be almost flush with the jam nut.
The oil cap should have a tiny hole drilled in the bottom side also so the tank can breathe. Those caps don’t always vent properly.

This or did the linkage get bent or damaged and did this so called mechanic properly bleed the ejection pump and all the lines?? An attempt of removal of the throttle body with having a brain fart resulting in the oil injection linkage getting bent can occur and so much of ALL of this sounds sketchy including dirty reeds, exhaust valves and to me it sounds like speculation due to TOTAL lack of any decent knowledge. As Ditch1000 mentioned about the injection lines, that's not the first time I heard about a motor burning down due to this.
I would say ditch this dude and find somebody else!! The same thing happening over and over tells me the same mistakes are happening over and over and you are the one facing the music.
The oil cap was often suspected of causing oil starvation when I read about lack of oil which is EPA nonsense and the pumps being turned down for emissions regulatons. The rattle inside is a ball that blocks off the vent in the event the sled is tipped on its side or right over so your oil doesn't drain out through the cap.

 

[davesilb]

It is either oiling problem or a lean mixture on the side that is showing the scuffing on the piston, Next time on the ride add oil to the tank at about 50 to 1. and if it makes it through the day note how much oil it used from the tank. This will tell you if the oil pump is doing its job. Then you can go from there. If it is seizing from lack of oil the 50 to 1 ratio should protect you from it happening again .

 

[ditch1000]

You should pull the motor out of the sled and confirm the oil line routing, connections and the flows.
When I had issues on my 2014 Assault; it was the same symptoms.
I couldn’t see the issue with the motor in the sled, but when I pulled the motor and tested the oil pump; I found the issue pretty fast.
Once I found that I had next to no oil on the mag cylinder and found the mag oil line and oil pump gear oil lines were swapped incorrectly on the oil pimp ports and then corrected that; I had zero issues after in 3 seasons until I sold the sled.
I wouldn’t throw any more parts at it until I knew the oiling is correct.

 

[ditch1000]

Also, what is the fuel filter like? When was it changed last? It could very well be plugged and leaning out your engine..
It’s one of the biggest reasons that the Pro engine burns down.
When I bought my 2013 Pro the guy told me it was on its second rebuild. When I asked him the last time the fuel filter was changed; he looked at me like I had 3 heads..
The sled sounded muffled but I reluctantly bought it because he dropped the price $500.
When I got the sled home, I pulled the fuel filter first thing and I could barely blow through it.
Luckily I had a really good used one so I threw it on temporarily until I got a new one and the sled sounds crisp after like it should sound!

 

[PWDRYETI]

Are you pulling the plugs because it feels like it’s hydro locked? This seems more than just oil cap. Is it one particular cylinder that is going down? Did it idle fine each time? What was the compression on the cylinders after you brought it back in?

yeah I'm just doing what I have done in the past to get the seized up motor free, and afterwards it did start but idled and ran bad after. it would not idle on its own without dying. I didn't do a compression test and am not sure if the mechanic did. I think it's always the same cylinder on the mag side. This time the cylinder got marred.

 

[PWDRYETI]

It is either oiling problem or a lean mixture on the side that is showing the scuffing on the piston, Next time on the ride add oil to the tank at about 50 to 1. and if it makes it through the day note how much oil it used from the tank. This will tell you if the oil pump is doing its job. Then you can go from there. If it is seizing from lack of oil the 50 to 1 ratio should protect you from it happening again .

thank you for the advice, that makes sense. unfortunately the damage to the top end is done. is there a way to check the function of the oil pump without risking another top end?

 

[PWDRYETI]

You should pull the motor out of the sled and confirm the oil line routing, connections and the flows.
When I had issues on my 2014 Assault; it was the same symptoms.
I couldn’t see the issue with the motor in the sled, but when I pulled the motor and tested the oil pump; I found the issue pretty fast.
Once I found that I had next to no oil on the mag cylinder and found the mag oil line and oil pump gear oil lines were swapped incorrectly on the oil pimp ports and then corrected that; I had zero issues after in 3 seasons until I sold the sled.
I wouldn’t throw any more parts at it until I knew the oiling is correct.

that sounds like sound logic, all of it. I don't know the condition of the filter or the oiler. I am gettin pretty frustrated with this mechanic because I specifically asked him to go through everything on the sled to make sure it was working properly. he's been out of town but will be back this week and I'm going to ask him these specifics. if he didn't check the basics and just charged me to replace the top end only to burn it down again because he didn't fix the issue I'm gonna be pissed.

 

[PWDRYETI]

This or did the linkage get bent or damaged and did this so called mechanic properly bleed the ejection pump and all the lines?? An attempt of removal of the throttle body with having a brain fart resulting in the oil injection linkage getting bent can occur and so much of ALL of this sounds sketchy including dirty reeds, exhaust valves and to me it sounds like speculation due to TOTAL lack of any decent knowledge. As Ditch1000 mentioned about the injection lines, that's not the first time I heard about a motor burning down due to this.
I would say ditch this dude and find somebody else!! The same thing happening over and over tells me the same mistakes are happening over and over and you are the one facing the music.
The oil cap was often suspected of causing oil starvation when I read about lack of oil which is EPA nonsense and the pumps being turned down for emissions regulatons. The rattle inside is a ball that blocks off the vent in the event the sled is tipped on its side or right over so your oil doesn't drain out through the cap.

I agree, I'm definitely feeling like I'm facing some ****ty music right now. I don't know anything about the throttle body or oil injection linkage but he should. I'll take notes of all the great suggestions you guys are offering. It is feeling a bit like speculation at this point from the mechanic because I haven't heard him mention any of this stuff to me, only charge me 3 times to fix the same problem without actually fixing it. now he's speculating that it's a bent rod causing the issue but says there's no way to know for sure because the bend in the rod can be undetectable to the naked eye. is that a blatant load of bullshit? I'm so over this dude.

 

[ditch1000]

When you pull the motor; you can pull the oil pump off and use a drill with a short piece of fuel line connected to the shaft to drive the pump. Thats how I test them and it works pretty slick!!
Keep the oil supply line on and use a small funnel full of oil to supply the pump.
If you have top end removed; both puddles in the crackcase should be equal.

 

[PWDRYETI]

You should turn the oil screw in like posted above and if the oil cap isn’t venting; it’ll put air bubbles in the oil supply line. So it is important to drill a hole in the oil cap or get a doo oil cap from an XM.
Also, confirm the oil lines off the pump are hooked up to the correct port.
I had a 2014 Assault where the mag side cylinder and oil pump gear were swapped and costed me a crank and top end within 100 miles.

I'll inspect the cap venting. as for the lines being on the correct port, is it possible those could've gotten swapped during the top end replacement?

 

[live2beel]

I'll inspect the cap venting. as for the lines being on the correct port, is it possible those could've gotten swapped during the top end replacement?

 

[ditch1000]

Better believe it could happen; it happened to me on a 2014 Assualt that I purchased with a blown top end.
The top lines on the 2nd and 3rd port from the left on the oil pump were swapped. It costed me a crank; when I pulled it apart and tested the pump, there was barely anything going to the mag side crank case. I swapped the lines to the correct ports and the oil flow was perfect after.
I rebuilt the motor from the crank up and never had a problem with the sled again in the 3 season I had it after!!