What could cause case sealant failure on almost new PV motor?

[JKMike]

Hey yaw,

Looking for some insight. What could cause the case sealant to fail in multiple locations on a 1000cc PV motor with only 8 hours on it? As I was getting ready for the season I found a big ass pool of oil in the bottom of my hull. Pulled the motor for a pressure test and it won't even hold 3 psi of pressure. It's leaking out the front back and sides of the case. Kind of at a loss for what could have caused this.

 

[bkspeedwerks]

damage to the cases prior to assembly, improper sealant used, or insufficient coverage of sealant is really the only way

 

[Quinc]

Didn't use loctite or re-torque after the first couple of rides?

 

[JKMike]

damage to the cases prior to assembly, improper sealant used, or insufficient coverage of sealant is really the only way

Yea this is pretty much what I came up with as well. I was going to attempt to just pull the lower case, clean and re-seal, but at this point I want to be sure everything is good so I'm probably going to pull the crank and pistons just to make sure everything is good.

 

[JKMike]

Didn't use loctite or re-torque after the first couple of rides?

There was definitely locktile on the bolts but I didn't retorque them after the first few rides. I'm not really sure how one could even do that without pulling the motor to get to the bottom of the case? Is that something that needs to be done on these larger motors?

 

[Myself]

I've NEVER retorqued case bolts. Dab of blue thread locker, torque, and run it. My only guess would be wrong case sealant. Some case sealants WILL NOT hold up to race fuels, or oxygenated blends. Many people swear by the "right stuff", let me tell you, it's the WRONG STUFF! I've personally seen it on customer engines turning into goo.

 

[Freakrider]

Which brand case sealant? It was a new unopened tube I presume?

 

[SteveC]

Outside of what’s here https://www.x-h2o.com/threads/best-sealant-for-case.133287/ (which reads like “what’s your favorite pizza topping?”), any concrete advice on what _should_ be used?

 

[WFO Speedracer]

Personally I have used Yamabond 4, Hondabond, Threebond 1211 and Permatex Motoseal, I have never had issues with any of those. I did have a lot of issues with Locktite 518 and I would never use that to seal cases even though Seadoo said use it, once I started using threebond 1211 a lot of our Seadoo issues disappeared .

 

[JKMike]

Is this a new to you Engine? Or is it a rebuilt Engine you've used before without this issue?

Are the Crankcases a true original matching set?

The Crankshaft Hole is machined by a Line Bore with both Cases assembled together, thus a Twin set.

Assembling a Top Case and a Bottom Case from different Line Bore job Sets might can cause enough misalignment to prevent a good mating of Top and Bottom Cases.

Or maybe the Case Bolt Hole Threads were/are stripped?

The motor is a XS1060 which I bought brand new around this time last year. Everything in it was brand new and it only has a little over 8 hours of ride time on it now. There doesent appear to be any stripped or crossthreaded holes in it.

 

[JKMike]

Which brand case sealant? It was a new unopened tube I presume?

I'm not sure on this one since it was a brand new motor.

 

[Big Kahuna]

Personally I have used Yamabond 4, Hondabond, Threebond 1211 and Permatex Motoseal, I have never had issues with any of those. I did have a lot of issues with Locktite 518 and I would never use that to seal cases even though Seadoo said use it, once I started using threebond 1211 a lot of our Seadoo issues disappeared .

Was the Loctite 518 the red sealant that only dries when two surfaces are mated? (Air circulation is cut off for no better term).

 

[JKMike]

Here are some shots of the cases.

 

[JKMike]

Was the Loctite 518 the red sealant that only dries when two surfaces are mated? (Air circulation is cut off for no better term).

"Anaerobic"

 

[Harbor]

Here are some shots of the cases.

That sealant looks like permeated black “The Right stuff” Rtv…

I’d use 1211

 

[JKMike]

That sealant looks like permeated black “The Right stuff” Rtv…

I’d use 1211

Thats what I though as well. I could pretty much wipe it off with my finger. Yea I used 1211 on my 735 motor and it seems to be working great. What about Threebond 1184? I have a tube of that and I can't recall what I got it for at this point but it claims to be resistant to gasoline.

 

[bkspeedwerks]

Thats what I though as well. I could pretty much wipe it off with my finger. Yea I used 1211 on my 735 motor and it seems to be working great. What about Threebond 1184? I have a tube of that and I can't recall what I got it for at this point but it claims to be resistant to gasoline.

i prefer 1184 to 1211. 1184 is designed for case sealing.

 

[Quinc]

There was definitely locktile on the bolts but I didn't retorque them after the first few rides. I'm not really sure how one could even do that without pulling the motor to get to the bottom of the case? Is that something that needs to be done on these larger motors?

I never have, but only run baby 701's. So not sure.

 

[Big Kahuna]

"Anaerobic"

I had that name stuck in my head.

 

[Big Kahuna]

Those cases look like there was barely any sealant used at all........... Who assembled it originally?