good times... being sarcastic

[Thumper3322]

good times... being sarcastic... Blown up piston...

Ridding along all good... Did a couple 180s and then it just stops.... Won' t turn over. Pulled the plugs and this is what I found. Pto is the crushed plugged.

UPDATE... pics below of head off.

 

[Thumper3322]

What do you think could cause this?

 

[LouDoo]

I think you need to pull the head and see whats going on, possibly a piece of piston ring, rave valve???

Lou

 

[Thumper3322]

Ya... Possibly the rave, but thinking the piston ring. Just wondering why.... Everything on the raves are new.

 

[LouDoo]

I know, I remember the last time, you know what Forest Gump said "sh*t happens".

Lou

 

[Thumper3322]

Ya.. Always happening to me it seems lol.

I can't take it apart till Monday. Sucks cause at a buddies cottage, 30 min out and no mire Seadoo.

How do the plugs look? Our at least the good one... Lean? Or just right?

 

[CReynoldsMIZ]

looks lean to me...it is my understanding that the diode should have more of a graham cracker type color.

 

[Thumper3322]

The mag one I think looks a bit lean too ... Maybe doc will know. Carbs just done so should be good.

 

[Dr Honda]

There was some glare... but they looked OK on the #3 pic. (other than the crushed electrode) Regardless... the one that broke was dark.


As Lou said... pop the head off, and let's have a look.

 

[Thumper3322]

Update piston head pics

Well tell me how Fed am I? Can it just be a top end, or you think some broken pieces have fallen into the crank, so need to rebuild the whole engine, or buy a new one?

WTF could have caused this AAAAHHHH... I did everything I could think of so this wouldn't happen. Spend some money now, to save the life of the engine later.

 

[Thumper3322]

More pics.......

 

[470]

Looks like you snagged a ring and the piston failed at the wrist pin. There are multiple possible reasons why but the motor needs to be completely taken apart and inspected.

 

[Thumper3322]

Is that possible... Or should I buy a new one?

 

[470]

It all comes down to money and time. Personally I rebuild everything though I get oem engine parts below wholesale and like knowing it was done right. While I have no experience with SBT, that might be your best and cheapest option. You really can't go wrong with their two year warranty. I guess the only thing that bothers me is the welded cranks. I'm not sure why they do it though I do have my suspicions. I only weld my cranks when spinning them north of 10,000 rpm and there not for jet ski use.

 

[LouDoo]

I was shocked when I saw the pictures you posted, that's about as bad as it gets.

I know the history of this engine more than most on this forum, I think it's cursed. If it were me I'd put it back together put in a box and send it to SBT, you're not going to be able to do it cheaper yourself, and if you have a chance of getting back in the water this year that's what you need to do. And the two year warranty doesn't hurt either.

Either that or get a voodoo princess and have the curse removed, probably in short supply in Canada. Anyway that's my advice, it's free so take it for what it's worth.

Lou

 

[Thumper3322]

470... Thx man... It's tempting to try, but as Lou has said, this engine seems to be cursed, so doing it myself would it just fail again.

Lou... I know you have been following and I appreciate it, but like you said it might not be worth it to even try to rebuild. Crazy issues right?! I thought I had something like this pegged not to happen, trying to be so careful.

Sbt the best to replace it? I was reading up on them, you have to keep certain parts like the flywheel, rotary valve etc? I thought it was more drop in connect cables, lines and go?

 

[Dr Honda]

Wow... that sux!

Yep... something snagged the piston, and ripped the wrist pin out. Then... the rod knocked the hole in the back side of the piston crown. I'm with the other guys on this. Call SBT in the morning, and just have them send you a new engine. You can be up and running in a week or so.


But... I know how you feel. Here's my Islandia engine. (Rod let go)

 

[Thumper3322]

Ouch... doc...

I wonder if it caught the rave valve.

Would you do sbt over full bore rebuild?

Sbt you have to exchange some parts like the fly wheel?

 

[Dr Honda]

Pop your RAVE's out. If it hit... you will see it.

I have no issues with SBT. Besides... they will send you an engine... then you put your old one in the box, and send it back. Full bore... you have to send your engine, and wait.

SBT sends a long block. So... you will put all your stuff on it. PTO, Flywheel, flywheel case, stator, Rotary vlave, manifolds... etc.

 

[Thumper3322]

I will tomorrow, but I can feel it, and feels beat up, but not surprised since the whole piston is screwed.
True... I will give them a call tomorrow and see about taking the engine out.

Doc you need to live in Toronto so I could just drop it off to you. I'm tired of this. LOL

 

[Thumper3322]

Here's a pic of the rave valve, smoked. It must of hit. You have no idea how much I thought about shaving . Wish I had. I wonder if they were over sized pistons, but when I turned the crank by hand they never hit. Hmmm

 

[Duane72]

Man I don't know if I've seen piston that bad even after working on cars for 20 years. The engine is definitely gone. No way to save and do just a top end. Doing a bore job on it would give you lots of opportunity to tweak and maybe upgrade some stuff... give your ski a little pizazz maybe, but if you're just looking to get what you had and get it back in the water then a rebuild is the most economical/time saving way to go.

Sorry to see it Thumper. Glad it didn't go through the block wall and take out more in the ski or even you though! An engine spinning at those kind of RPMs can send pieces flying with a catostrophic fail like that.

 

[470]

Here's a pic of the rave valve, smoked. It must have hit. You have no idea how much I thought about shaving . Wish I had. I wonder if they were over sized pistons, but when I turned the crank by hand they never hit. Hmmm

It may have not hit. You have so much carnage that some of those pieces may have done in the rave valve. I've seen hundreds of motors taken out by rave valves. Generally it's because someone bored the cylinder and didn't relieve the rave valve which is a must. The other one I see a lot of is speed shops boring cylinders and not chamfering the ports which usually results in rings snagging a port. Always use a machine shop that knows 2 strokes.

 

[LouDoo]

I agree, at this point it's really hard to say if it was cause or effect. Anyway it really doesn't make any difference. Don't beat yourself up over it, it's time to move on.

Lou

 

[Thumper3322]

I'm not... As Lou has said, this engine has a curse lol.

Trying to work out an sbt engine with a pro to install it ;-) I like learning, fixing these kind of things, but when going to dish out for a new engine, I want it done right, and please no more bs.

Btw what are your guys thoughts on sbt engines? Doc said he hasn't had problems with them.