Seized 2013 Pro 800 RK TEK

[SHAWNBRO]

My stock 2013 Pro 800 seized on my last ride. Unloaded it, let it warm up for 5-10 minutes, putting down the trail around 1/4 throttle and it shut off after 1.4 miles. Worked the clutch back and forth, motor freed up, limped it back to the truck. The upsetting thing is I put RK Tek direct replacement pistons in it 400 miles ago, hoping to prevent this. The motor is completely stock, running gold oil, premium fuel, replaced fuel filter, ect. (has been well maintained). It has 2500 miles on it. My main concern is if it will seize again when I put a new top end in it. I have drained all the gas out, turned the oil pump up, inspected the bottom end. Any ideas as to what caused the seize, and how to prevent it are much appreciated. Called RK Tek about warranty, he claims cylinder went lean, says he can sell me more pistons, but wont do any sort of a refund. Here are a few pics of the piston. Thanks

 

[Sickbuild]

hope you get it fixed

I know you are trying to do it all right but, who's to say it was rkt fault? My friend has a 5 gal bucket full of pistons from every brand and he locks them up all the time. It doesn't mean he should get a refund?...there are way to many variables . Many variables arise when a motor taken apart then get put back together. Some are legit faulty parts but in my case, most problems that arise are mainly always a result of me not checking or plugging in a connecter,ring gap, forgetting to put some thing back "right". (I just hate to admit it )
Sometimes I have no business attempting things but, I do because I've seen it on snowest!

Sorry about the motor. Hope the motor heads on here will give you some good feedback.

 

[SHAWNBRO]

Not saying its RK's fault. I know how bad the Polaris 800's are, I was just hoping the pistons would help prevent this. and the $400 would be really handy now that I need a new top end.

 

[89sandman]

Both cylinders or just one?

 

[richracer1]

FWIW, I let mine warm up till I see at least 120 or more on the MFD. It usually takes around 20 minutes or more depending temperature prior to start up. I also feather the throttle a lot.

 

[SHAWNBRO]

Just PTO side, both plugs, heads, and top of pistons look the same, scored worse on exhaust side, both sides have similar amount of oil residue in case/cylinders. after I was able to free the motor it ran on both cylinders. The only sign was that after unloading it it idled around 1200 rpm, but didnt die, after about 5 minutes of idling it came out of it and was back to 1800. can take or upload more pics if it will help, thanks

 

[dboivin]

did you check your ring gap or just install and go?

 

[SHAWNBRO]

I also let it warm up until around 100, and ride it easy for the first 2-3 miles. and yea maybe i should let it warm up a little longer

 

[SHAWNBRO]

gap was good, piston quality seemed good out of the box

 

[richracer1]

I also let it warm up until around 100, and ride it easy for the first 2-3 miles. and yea maybe i should let it warm up a little longer

Definitely couldn't hurt.

 

[Snowmow]

Is the ring end gap set on the RKtek pistons or did you do that on install?

Any bubbles in the line going from oil tank to oil pump?
Been using oil consistently?

 

[Snowmow]

There was a guy on here a few months ago that had your exact experience TWICE IN A ROW!! Ended up being the oil tank wasn't venting and wasn't supplying the oil pump with oil.

 

[SHAWNBRO]

gap was good out of the box, did not have to adjust it. Looked at oil lines, no bubbles, has been using same amount of oil

 

[SHAWNBRO]

Thanks i will look into venting my cap, any opinion on the best way, Paaso, will the Ski-Doo cap thread on,

 

[Snowmow]

I'm running the new doo cap. With the duck bill style valve in it. There is a lengthy thread on that

 

[Sickbuild]

Sounds as though motor maybe was starving for some fuel at idle.
(Injector), then took it down the road on a semi warmed up engine and locked up.
thermostat opens at 120? If I remember, so going down road then it opens sending cold coolant- finishing it off? I don't think it's a cold seize, just might have compounded it.

or piston was hanging up from the get go creating drag/low idle ( rings).

When was fuel filter done? Was it done at the same time? Just trying to rule out things etc.

 

[SHAWNBRO]

Fuel filter was done around 1800 miles, recommended every 2000 miles. Yea thermostat starts opening around 120 or 125, and doesnt have a bypass, but it had already been above 125 for at least a half mile so i doubt it was a cold seize. I am wondering if the injector dropped out, or froze for a second, but it was running on both cylinders after. I havent heard of any injector problems after 2011. But you may be right, injector could have been frozen, at idle scored piston, thawed, then seized when it warmed up. thats my best guess at the moment, open to other ideas also

 

[tatorsalad]

Did you add oil two the first tank of fuel

 

[Snowmow]

I don't think the sled would have idled smoothly for 10 min with a bad injector...... 1.4 miles is what? 7 min of riding at 10mph? I'm saying no lube, but I guess with no lube, should see both Pistons damaged not just one........ Hmm

 

[SHAWNBRO]

Yea I always run a little extra oil in the gas, but yea put in extra after installing pistons. Yea id say less than 10 minutes of riding. its a multi-hole injector, id have to look again but i think there are 6 or so holes, im wondering if half of them were froze making it lean and scoring the piston.