Water leak Dasa 950

[KeastaFR]

I’ve just put a Dasa 950 in my ski and it’s leaking water around the center nut on the head. I pulled the head off and the orings are all fine and there is no visible damage to them.

Anyone had this issue before?

 

[KeastaFR]

Did you grease the O-Rings before installing them?

Did you cross-torque (from the Center outward) the Head Bolts in two stages minimum, say 12 ft-lbs, then 22 ft-lbs? (not sure what the final torque should be on a Dasa 950 (my numbers are for illustration only.)

Did you re-torque the Head after your first ride/heat cycle? After your first ride, let Engine cool down, then re-torque to Dasa 950 spec.

I haven’t had it in the water yet it was just on the flusher when it was leaking. Hose pressure.
But yep, I did all of the above things mentioned. Was thinking if the sleeves were to low would this create a sealing issue.

 

[KeastaFR]

Thanks for that bro!!

 

[Big Kahuna]

There should be no water coming out of any bolts on the head. The bolts do not go through any of the water jacket. Only way for this to happen is 1. You have a cracked head. or 2. Your head is not torqued correctly or you have a busted O-Ring.

 

[Harbor]

Wonder if it could be the hose from the house was opened too much ? Isn’t household pressure in the 30 psi range ?

The outer head shell bolts are outside the perimeter oring and outside the water jacket. The center bolt is within, only thing NORMALLY keeping water from wicking up the bolt is the matting surface finish on the head shell and cylinder deck, there’s no sealing on this bolt..

Can’t go wrong calling Kyle.., good suggestion ^^^

Edit: might put the ski in water and see if it leaks under its own water pressure

 

[Freakrider]

"Center nut on head" does cylinder have studs like some TPE cylinders? If so they require sealant around studs to prevent leaking out of head.

 

[mikidymac]

Wonder if it could be the hose from the house was opened too much ? Isn’t household pressure in the 30 psi range ?

The outer head shell bolts are outside the perimeter oring and outside the water jacket. The center bolt is within, only thing NORMALLY keeping water from wicking up the bolt is the matting surface finish on the head shell and cylinder deck, there’s no sealing on this bolt..

Can’t go wrong calling Kyle.., good suggestion ^^^

Edit: might put the ski in water and see if it leaks under its own water pressure

Typical house pressure is 60 psi but I have no idea what a PWC pump water pressure is.

 

[KeastaFR]

Thanks for the feed back, got a few thinks to look at or try out.