Engine go Boom!!

[Rave]

On trail to riding area, 30 mph, light throttle. Heard a bang, coolant everywhere, hole in engine case. Took it apart tonight and found that the PTO connecting rod broke about 2" above crank pin. Any one else seen this happen? Thoughts?

2005 Summit X

 

[Summit8]

High miles? Crank/Rods tired??

 

[Rixster]

Wow, look at all that blow by. That motor was WAY past time for a rebuild.

 

[1500psi]

Sd

Seen it many times. Ski doo been using that same 1500 mile motor for way too long now..

 

[teeroy]

had an '03 800HO break the PTO con rod last month, but closer to the piston. left enough rod on the crank to poke itself thru the front and back of the case, as well as though both sides of the jug. totally ate it's pigs

 

[eddy]

Boom

Piston sloppy, rocks in bore, skirt breaks off, jams rod, breaks rod. Common to all two strokes. Solution is to replace pistons before they start rocking to much. You can probably see on the piston that did not break that there are wear marks on the very bottom of both intake and exhaust side lower skirts.

 

[Rave]

High miles? Crank/Rods tired??

Less than 300 miles since new crank and pistons.

 

[PJ-Hunter]

Less than 300 miles since new crank and pistons.

Then you had some other issues. That blow-by is a dead giveaway that you had a bad piston/cylinder. Did you use OEM? I'm betting that if the pistons were good, the rings installed right you probably had cylinders that were out of spec and in dire need of a re-nik. New pistons in a poor cylinder is just as bad as old pistons in a new cylinder.

 

[dicey]

Was it rebuilt with spi or spx pistons my freinds just did the same with low miles

 

[tukernater]

Then you had some other issues. That blow-by is a dead giveaway that you had a bad piston/cylinder. Did you use OEM? I'm betting that if the pistons were good, the rings installed right you probably had cylinders that were out of spec and in dire need of a re-nik. New pistons in a poor cylinder is just as bad as old pistons in a new cylinder.

Yep I agree

 

[RKT]

On trail to riding area, 30 mph, light throttle. Heard a bang, coolant everywhere, hole in engine case. Took it apart tonight and found that the PTO connecting rod broke about 2" above crank pin. Any one else seen this happen? Thoughts?

2005 Summit X

Yes, this is common when you use an aftermarket CHEAP chinese piston like you have used.. Sorry, guy, not trying to rub it in, but you asked for a reasoning and that cheap piston is the reason you now have a worthless engine.
I get this same call weekly and the common variable is always the Chinese piston installed.

This is why we offer a high quality piston that will NOT destroy your engine.

Sorry for your mis-hap... I have a complete bottom end with new, reman, crank ready to go at my shop...

Again, bad deal, but at least the cause of the failure is known..

 

[tukernater]

Seen it many times. Ski doo been using that same 1500 mile motor for way too long now..

Ya it's not always BRP's fault got over 7400 miles on my HO,But IF you have a PSI engine i'm sure your no stranger to daily maintenance.

 

[Rave]

XM in my future

Thanks for the input/responses. Pretty much decided to sell/part out the Rev and get an XM.

Good bye old friend, it's been a good ride!!!

 

[blk9038]

Thanks for the input/responses. Pretty much decided to sell/part out the Rev and get an XM.

Good bye old friend, it's been a good ride!!!

love my old rev also and rebuilt it with the pistons from rktech now the rev is my backup and you will love the xm, i have rode alot of differant rev's . xm out of the box is so much better.

 

[Summit8]

My 02 had well over 3k mi. on it before the crank went south, a few years of no dpm, carbs rebuilt by Xtreme Perf. w/ Jack Harris Needle Jets, ran Wiseco pistons before running BJ's 840 HO top end, which was installed w/ the reman and trued crank by BJ.