12 Superjet top end twice

[CameronPerdue]

so last fall my 12 scuffed a piston with about 30 hours on it. So I got 1mm over prox pistons

Got a local watercraft dealer to bore them out to spec, and then I assembles the engine, also replaced crank seals due to oil in the stator

Shoulda just broke it in but winter came..

So I got a wammer b pipe and installed with dual cooling
Previously have Ada head and msd

Just took it for a break in ride 2 weeks ago. The water was 65 and seem to run on, engine bearly warm tho. Was out for 30 min

Compression test after = 120/170

Boom

 

[CameronPerdue]

Pics

 

[CameronPerdue]

Pic

 

[CameronPerdue]

One piston missing a chunk. The other gouged the cylinder.

I have never assembled a sj engine but I have done dirt bike and sleds before

 

[tomski]

Look at the arrow on the piston.

 

[Quinc]

The arrows on the pistons should be pointing at the exhaust ports. Before you rebuild again read through this thread a couple times;
http://x-h2o.com/index.php?threads/how-to-assemble-a-701-motor.68398/

 

[CameronPerdue]

Yep.. not a proud moment. Took the wrong advise from someone.

 

[Quinc]

Yep.. not a proud moment. Took the wrong advise from someone.

The piston rings also go upside down compared to the instructions that come with the pistons.

 

[Quinc]

Read through all of these threads when you get a chance. Tons of knowledge in here.
http://x-h2o.com/index.php?forums/tech-faq.26/

 

[CameronPerdue]

My Four stroke knowledge led me to thing an intake marking.. lol expensive mistake,

Now.. bore out this jug again or just get a freshie?

 

[High Speed Industries]

You still have a little more life in that cylinder.

Go to a 82.5 or 83mm piston.

Tomski might have a clean take off cylinder with Pistons. It's not a bad way to go.

 

[CameronPerdue]

Got some 83mm on the way, I'll get it bored once I get the Pistons... Round 2 this time.



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[Quinc]

Might as well port it too. Hit up @yamanube for some porting templates.

 

[CameronPerdue]

Might as well port it too. Hit up @yamanube for some porting templates.

Hmm . What all goes into that.


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[Quinc]

Hmm . What all goes into that.
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Check out his thread. It has pictures and tool recommendations. More or less a template that anyone handy with a dremel can use on your exhaust port for more low end torque.

 

[Vumad]

http://www.x-h2o.com/index.php?threads/jetmaniac-blue-freestyle-ported-top-end-kit-650.106417/

 

[bored&stroked]

dual cooling in 65* water is a bit overkill.

 

[CameronPerdue]

dual cooling in 65* water is a bit overkill.

Was thinking that too, wammer said it would be fine but didn't make much heat, Should I put a restrictor in the 2 pissers?


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[CameronPerdue]

Check out his thread. It has pictures and tool recommendations. More or less a template that anyone handy with a dremel can use on your exhaust port for more low end torque.

Does this effect the top end? I just rip bouys and jump boat waves around here


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[Quinc]

Does this effect the top end? I just rip bouys and jump boat waves around here

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It will make everything better.