Bad day melted piston!!

[99seadoogtxltd]

Itll be a couple hours before I get back to the house to take them.
Would it be dangerous to make any head modifications? And if it wouldnt, what would be a good modification for a little more hp for recreational use? I know we are getting into the grey area of reliability also. But if I am going to go through the engine, I'm going to bore it out .50 over and go from there. I am pretty sure I have to get a new head already. The old one is pitted really really back. It actually looks melted but there is totaly possibility for something getting in there and beating it up. Ill provide pics soon and let everyone make the speculations for me. I believe the 951 is pretty good to be able to make it back to the trailer from a few miles away like that. And it didnt mess anything else up. Looks like if it was that bad, it would have seized up before I got back in with it. it was sputtering and backfiring pretty bad, thats why I thought it was the carbs to begin with. SURPRISE! YAY ME!

 

[Sportster-2001-951C-Stock]

Itll be a couple hours before I get back to the house to take them.
Would it be dangerous to make any head modifications? And if it wouldnt, what would be a good modification for a little more hp for recreational use? I know we are getting into the grey area of reliability also. But if I am going to go through the engine, I'm going to bore it out .50 over and go from there. I am pretty sure I have to get a new head already. The old one is pitted really really back. It actually looks melted but there is totaly possibility for something getting in there and beating it up. Ill provide pics soon and let everyone make the speculations for me. I believe the 951 is pretty good to be able to make it back to the trailer from a few miles away like that. And it didnt mess anything else up. Looks like if it was that bad, it would have seized up before I got back in with it. it was sputtering and backfiring pretty bad, thats why I thought it was the carbs to begin with. SURPRISE! YAY ME!

I guess you could get a performance head if you wanna bump up the compression some, or maybe cheat with a thinner cylinder base gasket (there are several different thicknesses available) assuming you don't make the squish band at the head & piston whacko tight. I've removed base gaskets completely before to get more compression, but modifying 2 strokers never seems worth the hassle.

Higher compression moves the engine closer to detonation, why not if you need more power then get another ski? Like maybe one of those new 4 stroke skis with an NOS bottle?

I want to know if the top ring land was collapsed and if it pinched the top ring, and I want a description and pic of the puddle of oil in the bottom of the crankcase. And good pics of both pistons.

 

[99seadoogtxltd]

It had right at an 8th of an inch of oil under the rod bearing?

 

[Sportster-2001-951C-Stock]

It had right at an 8th of an inch of oil under the rod bearing?

Okay, was there enough oil for the rod end to dip into and get wet(splash) while rotating? My guess is maybe just enough.

 

[99seadoogtxltd]

 

[99seadoogtxltd]

 

[99seadoogtxltd]

 

[99seadoogtxltd]

 

[99seadoogtxltd]

 

[Sportster-2001-951C-Stock]

Is that top ring on the roached piston rotated to where the ring ends were in one of the ports? Kinda looks that way, if so, is the anti-rotation pin sheared? The 2nd ring land looks like it's way too wide for the ring, I have to compare it to mine now.

The scoring on the good piston makes it seem like it may have not been living a happy life either, and the land/ring clearance on the second ring looks huge as well. I'll be looking closer at mine while cleaning the raves soon to see if it's like that, you've got me wondering if that scoring there on the good piston is from the rave blade being too long or if the oil film failed near the exhaust port

Crank wheels are wet, should've been enough oil. Maybe the wrong type played a part, dunno.

Some new plugs and maybe clip a bit off the wires and you'll be good as new!

 

[99seadoogtxltd]

Well, this is an sbt engine. I have heard good and bad things about them. I plan on doing this myself so that I know what everything looks like.Would you think a oil block off plate and a top end rebuild would take care of me for now?

 

[Sportster-2001-951C-Stock]

Well, this is an sbt engine. I have heard good and bad things about them. I plan on doing this myself so that I know what everything looks like.Would you think a oil block off plate and a top end rebuild would take care of me for now?

I guess it should work as long as a bearing in the bottom end doesn't let go. The 951 is junk to start with, money pits they are.

If I was planning to keep running this thing for years, I'd want to play with it and see. I'd probably look for a spare motor with good casings to build up for quick swap outs. Everybody says the bottom ends are done once the top blows up but I'd probably try it.

Kind depends on what ur expectations are..., something as trouble free as possible or a test bed for experimentation. Sounded almost like you wanted more ski, didn't have enuff giddie up.

You could go all out and measure the bore, buy a piston to fit(the good one is probably marked) and a gasket set, new wrist bearing and retaining clips then slap it back together. Does the small end on both feel the same in comparison? I kinda wonder if the crank is bent or something like that, does it spin free?

 

[99seadoogtxltd]

Oh I liked the speed it had to be such a big boat, it was impressive! Most people are spending huge amounts on xps and I wasnt very far behind and it was stock! Plus the ride of it was like a dream. What is the most reliable ski/ engine?

 

[Sportster-2001-951C-Stock]

Oh I liked the speed it had to be such a big boat, it was impressive! Most people are spending huge amounts on xps and I wasnt very far behind and it was stock! Plus the ride of it was like a dream. What is the most reliable ski/ engine?

Well, motors get more reliable the smaller they get and speed costs money, I guess. Maybe someone could compare the yamahaha 3cyl 1200cc for you, those things have more giddie-up, I think.

Four strokes are cheapest to run of them all, very durable but aren't impossible to blow up either and if you do then more $$$ to get it going again.

Hard to say.... I kinda like the 951 for some reason.