Broken DASA Power Valve

[Ken23]

I need some help. I am running a DASA 950 with power valves, this weekend in between rides I found that my front power valve broke. This is the second time in 1 year this has happened to me.
After the first power valve broke I had the engine rebuilt with 2 new power valves that were cut to match the cylinders, the engine has approximately 25 hours on it since the rebuild.
Has anyone else experienced this?

 

[DAG]

da fug? how is this even possible?

 

[jo5hi3]

Subed

 

[OtherDonnieGuy]

Reminds me of Polaris Liberty motors lol those things will come apart and sometimes make their way out of the exhaust and still run!

Are these pv's stainless?

 

[Ken23]

We have nosed in several back flip attempts that has caused the ski to sub. Do you feel water entering the engine could break a power valve? I never considered that.

I believe the power valves are aluminum.

Thank you for your responses, I am totally lost and frustrated.

 

[Christian_83]

Water entering the engine and water lock it, and that will cause your engine to be in pieces.
Did you speak to your engine builder or DASA? This seems really strange.
Did have this engien from new?

 

[Ken23]

I did not have the engine from new. I spoke to DASA when the first Power Valve broke, we assumed it broke because the screw that connects the power valve to the top fell out several times and figured that the tightening of the screw numerous times fatigued the shaft causing it to break. The screw has not came out of the power valve that broke yesterday. I have spoke to the engine builder but have yet to bring him the engine for further analysis.

 

[DAG]

Did they both break at the same spot?

Both breaks on same cylinder?

When you bought new, did you buy just the valve or the complete assembly with the mounting base?

When you assembled did you confirm the valve clearanced the rings by cycling the piston up and down the bore?

 

[Ken23]

Yes both valves broke in the same spot.
Same cylinder front.
Just bought the valves.
We did check the power valve to piston clearance during the machining process. There are currently no signs on the the power valve that it contacted the piston, I have not yet removed the head. I have my fingers crossed that the cylinder/piston are not damaged.
The ski was running great just came back into add more fuel before going back out. I did not really notice a loss in power at the the time but before completing the ride I was struggling to make it all the way around on a back flip. I assume it was due to the power loss caused by the broken power valve. Or maybe I was just getting worn out. LOL.

 

[Jr.]

Have you checked the dimensional clearance of the giotine body to the cyl slide?
Excessive clearance will cause the giotine to rock in the slide, putting side pressure on the stem.
DASA will need to give you the clearance specs per their design.

 

[Ken23]

Thank You. I have reached out to DASA. Do you know if Kyle Kennedy is still working for DASA?

 

[Big Kahuna]

don't believe he is.

 

[Ken23]

Thank You. That probably explains why I haven't received a response from my email. LOL

 

[Kaylee.S]

don't believe he is.

Since when? He was still there like a month ago...

Can you take a picture of the face of the fracture? We may be able to tell you the failure mode. Seems like it propagated from the stress riser where the small diameter stem meets the larger diameter...but why? May have started from over tightening the pv screw?

They are aluminum btw

 

[KMN]

I got an email from Kyle 6 days ago, I'm pretty sure he's still there. He's pretty busy though and sometimes takes a few days for a reply.

 

[Ken23]

Thank You Kaylee. I will get a few more pictures posted later this evening.
I have only used a allen wrench to ever tighten these screws, do you feel enough torque could be generated to damage the valve using just and allen wrench?

 

[Big Kahuna]

Guess I had heard wrong.

 

[Kaylee.S]

Thank You Kaylee. I will get a few more pictures posted later this evening.
I have only used a allen wrench to ever tighten these screws, do you feel enough torque could be generated to damage the valve using just and allen wrench?

Being aluminum... I'm pretty confident one could do some damage with just an allen wrench.

 

[High Speed Industries]

Guess I had heard wrong.

You didn't hear wrong. There was a time where Kyle left DASA (about 2 years ago). DASA kept needing Kyle for odds and ends after he left. Eventually he got pulled back into DASA to oversee their watercraft department.

 

[DAG]

Guess I had heard wrong.

He did leave to go to worx a couple years ago? But been back a dasa for awhile? Or maybe he's working both. It's weird