Lost a piston. Need some help

Location
Missouri
Hey guys I have a 93 B1 that I was out riding this past weekend when all of the sudden I lost power, the ski died, and I could no longer keep it running. Called a friend and he said to go ahead and pull the head. Pulled the plugs first and found that the rear plug must have hit the piston because it no longer had a gap. After pulling the head I found that I had lost a piece of my rear piston.

Ski is a 701 bored once over from previous rebuild about 5 years ago.
Running 45:1 premix
Protec head and exhaust

Looking to get a ballpark on how much this might cost to fix, if I should part ways with the ski, or just find a new motor??? Any help would be greatly appreciated. Thanks

photo1.jpg photo2.jpg
 

Big Kahuna

Administrator
Location
Tuscaloosa, AL
looks like wrist pin bearings let go.

Pistons will run you about $200.00 with gaskets.
Bore Job $150.00
Possible need a new head if domes are trashed.
Do the Labor yourself on the rebuild. Remove the bottom end and flush and inspect to make sure it not part of your crank bearings.

This on the low end on the pricing.
 
You have to remove the cylinder anyway. Then you can check for damage below. It's quite likely that the large rod bearing (crank pin) failed. You'd be able to see it then.
 
Location
Missouri
To be honest I have never taken apart, nor rebuilt a ski motor. I am mechanically inclined and have no issues learning via directions and such, but would it be possible to tear down and rebuild on my own considering I have never done it before?

I would love to fix the ski without breaking the bank, as I just graduated college. Thus being able to work on it slowly on my own would probably save money compared to having someone do it for me.
 
These motors are super easy to work on, once you tear it down you'll see just how easy they are. Just document everything as you take it apart or take pics if you're worried about not putting it back together right. The manual also has all the torque specs you'll need.
 

Wakerider26

Peter Waldron -doing jetski tricks
Location
Alabama
Dude, SBT will send you a whole short block 62t or 61x for like $500-$600. Just swap heads when you get it.

That way you don't have to worry about doing something wrong, or leaving a piece of metal in the cases. I recently did the same thing with an SJ. Piece of cake.
 
Location
Missouri
I’ll have to post pictures of my Protec head when I go to the lake this weekend. It could potentially be shot too, the dome looks just like the top of the piston with pieces of metal imbedded all over. I imagine that could be sanded out, but only to a certain extent?

If I went the SBT route is it worth it to go for the premium vs the standard engine?
 

Wakerider26

Peter Waldron -doing jetski tricks
Location
Alabama
Standard. Premium comes with some extra stuff you don't really need. Like break in oil, a calender, and an extra year of warranty.
 
Location
Missouri
You got to start somewhere. I rebuilt my first 550 motor on the kitchen counter......... My Wife did not like it. But I think she even helped!
Haha if I decide to build it myself it will be in the back room at the lake or on my bedroom floor in my apartment. Either way not the best place.
 

Quinc

Buy a Superjet
Location
California
They look over whelming at first but once you get her apart it is pretty simple. There is even a guide in the FAQ section with step by step pictures on how to take her apart.

Contact @Nuklear6 or @JetManiac

You can send your cylinders off to them and they will make sure they are perfect when you get them back with the right size pistons etc. And for a little more money you can get it ported for some more power.
 
Location
Missouri
Thanks for the info, just read that whole thread. Due to the abundance of pieces of metal visible in the cylinder if I were to take on the task myself, when I disassemble I will be looking for pieces of metal down in the crankcase right???

I know previously when I had to rebuild my crank was shot, what is the way of knowing if their is any damage to the crank?
 

Quinc

Buy a Superjet
Location
California
Download the manual and there are tolerances you can check. Best to pull the crank out and make sure there is no metal pieces in the bearings etc. Or if you are lazy you could give it a good solvent bath and stick magnet down there.
 
Thanks for the info, just read that whole thread. Due to the abundance of pieces of metal visible in the cylinder if I were to take on the task myself, when I disassemble I will be looking for pieces of metal down in the crankcase right???

I know previously when I had to rebuild my crank was shot, what is the way of knowing if their is any damage to the crank?
The carnage to the rear crank pin will be quite visible
 
Rod bearing and thrust washers fail, that does ruin the crank. Used ones can be found, but it's always a guessing game how much life they have left. SBT has rebuilt ones. Member " jetmaniac" sells quite a few of them. OEM is nice but expensive (about 650 street)
 

baxt3r

BBQ
Location
Charlotte, NC
Tackle this yourself. I had a huge hang-upbabout even putting my ADA head on my ski because I didn't have any confidence in my abilities. I'm fairly mechanically inclined. New things spook me a bit. I could have kickedmy own ass for worrying too much after I saw howsimple these motors are.

You hhave a wealth of information here at your fingertips and a good group of guys that can talk you out of just about any jam you might find yourself in.

If, for some reason, you find yourself past your comfort zone, there are several VERY capable vendors here who can help.

Afraid of the engine you should not be. - Yoda
 
Top Bottom