Cheap 951 project build

[SrSalvageSki]

let start this off with yes I know there is nothing cheap about "Building" a 951 lol. little over a week ago I acquired a GSX L and a trailer in extremely good shape for only 100.00 bucks. hull looks beautiful its a really nice looking ski BUT the kid sunk it.....he had been out riding it and it died on him so they towed it in back to shore. in the process the ski flipped and took on water. it sat for a few days until he realized he was in over his head and I came about and in the dealing ended up saying heres a 100 bucks. took the ski home flipped it pumped the water out oiled and coated everything down the plug holes and through the rave ports i did anything at this point to fight any form of rust. ran a compression test after getting the engine good and dry and she still sat at 180 in each cylinder. after pulling the carbs running through them and swapping the fuel out.. the ski came alive. it ran it idled it cooled it did everything it should. now I know that most will say once salt water is introduced into the system there is no bringing it back. I took the ski out to the water and it ran great for about 25 min until it sputtered out and locked lol ok that's where the only a hundred bucks started to really feel nice. so I bring it home pull the motor and found that the top of cylinder 2 the back hole was beaten to hell...… I pulled the top end off and found one perfect piston and half side of the jug... and the other piston destroyed but the cylinder is fine the skirt is fine and the rings are fine,,,, so to me it seams that it sucked something into the cylinder by the looks of the small steel pieces i found stuck in the piston and head cap. ...…. Now the question... I know im into it for a top end build without question. I know the cranks are the real issues here but this one seems tight and looks fine despite the water issue …. should i bother getting into the bottom end adding another 360 for a crank from sbt or should I use the bottom end out of another 951 ski I have that the bottom end is fine but needs a top end..... combine the motors for one or buy new. Id rather save money but if i need to buy I will.



sorry for the length of the post

 

[etemplet]

How do the bearings feel in the bottom end? I listened to one as I turned it a number of different times trying to hear or feel a reason to replace or not replace the crank. I filled the bottom end with oil and let it sit for about a week. I must have checked it 10 times. If I don't have a reason to change/replace a part, I won't do it.

 

[SrSalvageSki]

crank assembly spins freely no snags no side to side play not much weird movement at all. I don't see any reason why it would be bad. I think ill split the rest of the case and inspect everything visually while I have the motor out. guess ill be ordering the top end kit tomorrow.

 

[etemplet]

I dunno... by what you describe I think I'd leave it all together. Lotta work and you could create a new issue that was not there previously. Good luck. Post some pictures... inquiring minds and all that. LOL

 

[mikidymac]

I am pretty sure the metal bits embedded in the piston are going to be a bearing from the crank or rods.

Have you pulled the piston pins to see if all the needle bearings are accounted for?

Btw you can get an OEM crank from seadoo for $420 that’s way better quality than SBT.

 

[SrSalvageSki]

Lets see if this works??? I like motors not computers lol

 

[SrSalvageSki]

Went back out to the shop today to snap a few pictures... I puled the pistons off to check wrist pin bearings and everything checks out its deff not one of them that was sucked up. the case if reused needs to be split and inspected and either way used or not cleaned cuz theres all kinds of stuff down in there. that one pic of the cylinder that made it up is the one where the piston was fried up in. both holes look smooth no major scratches I don't think its anything a quick hone could clean up to make the cylinder reusable. the other hole looks even better. NOW correct me if im wrong but if the cylinder was going to suck up a crank bearing wouldn't it have to get past that piston ?? thus destroying more than we have here ???. After taking the pistons off the rods I was able to get a better feeling of the rotating assembly and it deff feels like there may be a stiff spot in the rotation like something is grabbing somewhere so im gonna go ahead and prepare to get another crank. yes I know seadoo is deff a better product but iv read nothing but good about SBT and their products. gonna get a preassembled crank because i don't want the press process on my hands.

 

[etemplet]

I've never considered doing my own crank assembly. I priced the parts and I wouldn't have been saving money enough for all the trouble for sure. I have a couple of 951's that need a full rebuild so post some pictures of the bottom if you please. I gotta get me one of those little rollers to apply the motoseal. Part of my problem is I won't buy special tools that make the job go easier. LOL I'm getting past that now.

 

[SrSalvageSki]

ill split the case today and post up the pics later tonight ill bet ill find a few or atleast one jacked up crank bearing.

 

[mikidymac]

The seadoo crank is a full drop in, nothing to rebuild.

On a 2-stroke the fuel and air enters the crankcase then is forced up through the transfer ports in the cylinder walls into the cylinder and above the piston when it is down. So anything in the crankcase will end up on top of the piston.

 

[SrSalvageSki]

is the sbt assembled crank not a drop in replacement ?

 

[mikidymac]

Yes SBT is also. I was just stating that since you didn’t want to rebuild a crank which isn’t a DIY job.

 

[SrSalvageSki]

So today I ran a hone through the cylinders....and obviously one was worse than the other. Ring gap was rather loose something like 45thousands so obviously things are worn. The hone isn't going to be enough here its deff going to need to be bored out a little for some larger pistons and brought back to round. Another finding here was after a little look at the pistons I see they are SBT pistons so someone has been in here already and chances are this cylinder could already be bored out to a larger size I didn't get measurements so I don't even know what size im coming from let alone what size to bore out to .. Im just starting to find my places around here cuz Iv only been in Florida for two years. The machine shop I was going to use no longer does anything aluminum soooo now I have to find another place. After more reading im seeing that the RAVE's need to be trimmed back to avoid possible contact with the piston. Im seeing that FULLBORE online can get me the whole thing squared away kinda like a one stop shop... Does anyone have an average turn around time on them?? id like to get this thing back together sooner rather than later and there are other available machine shops.

 

[mikidymac]

951 is about the cheapest engine I know of to rebuild, besides maybe another Rotax by a few bucks? Price can go up if it was grenaded though and this is a good reason to use quality proven parts.

I love junkyard builds BTW, and run what you brung.

Not sure how you figure the 951 is any cheaper to rebuild?
Parts alone for a rebuild...
951 = $810
787 = $755
720 = $665.

To the OP, Fullbore is good but remember all shops are in peak season now so you are going to wait.

Your cylinders have cast iron sleeves so any shop should be able to bore them.

 

[mikidymac]

Mercruiser $6K, sure looks cheaper to me. You try too hard to twist my words around.

Sorry, I was thinking 2-stroke skis, my bad since I wasn’t thinking boats. But the 951 is the most expensive Seadoo 2 stroke to rebuild, still cheaper than the Yamaha Kawasaki and Polaris triples.

I apologize Sportster, I have been doing the Yamaha 701’s recently that are even cheaper so that’s where my head was.

Yes, $6k is expensive so are the 4 strokes.

 

[etemplet]

Well since this is a 2-stroke Seadoo forum I was thinking along those same lines. Aren't 951's the most expensive Seadoo 2 strokes to build? LOL

 

[Ckrawiec]

Well that escalated awkwardly.....you say the waters cold, I'll say the waters deep too.....Can't we all just get along?...Let it go boys...all friends here...

 

[Sportster-2001-951C-Stock]

Sorry, I was thinking 2-stroke skis, my bad since I wasn’t thinking boats. But the 951 is the most expensive Seadoo 2 stroke to rebuild, still cheaper than the Yamaha Kawasaki and Polaris triples.

I apologize Sportster, I have been doing the Yamaha 701’s recently that are even cheaper so that’s where my head was.

Yes, $6k is expensive so are the 4 strokes.

Why it every single post I place here you MUST respond to telling me I'm wrong? I just want others to know why I'm gone.

 

[etemplet]

Well then....

 

[mikidymac]

Why it every single post I place here you MUST respond to telling me I'm wrong? I just want others to know why I'm gone.

Sorry you feel that way. I was trying to apologize for misunderstanding what you said. So again I’m sorry.

If anyone is wrong it should be brought up though so we keep good info going. I have been wrong and would expect someone to say something if I am.

 

[etemplet]

I like Sportster and he has provided lots of good information on the board but if it upsets him when people don't agree with his posts... it's probably best he doesn't post.