Water in back cylinder

[Cruiserfj40]

I've been having an issue for a while now and cant figure out what is going on. Engine starts and runs great. Seems to make good power but I'm getting a little water in my back cylinder. Plug always is a little milky, piston looks washed out right where the intake ports come in, power valve keeps gumming up. I though it may have been splash from coupler getting into the carb but ruled that out riding with no hood and a dry hull.

I recently changed out my exhaust to a laydown and am still having the issue. I pressure tested the cooling system and it held pressure. Today I ran it on the stand with the hose hooked up. It ran it for 5 min straight then pulled the plug and PV, they rear were milky. I cleaned them off and ran it again with the same issue. I forgot to un-hook the spray bar in the exhaust to see if maybe it is sucking it back in. I went back in and plugged off the cooling system and pressure tested again. This time at 60psi and left it for 3 hrs. It's holding still. I started it for only a few seconds with the cooling system pressurized to see if it possibly is a compression / sleeve issue but it held pressure. I want to run it a little longer but it's getting late.

Could a bad reed or leaking intake cause the rear cylinder to suck water back in through the exhaust? Any other thoughts on how water is getting into the engine from the cooling system/ exhaust? This has been on two different exhaust systems. Factory pipe and TNT manifold.

Tomorrow I'm going to run it for a little longer than a few seconds with the cooling system pressurized. Only thought there would be a leaking sleeve into the case. Like I said the piston is really clean right at the intake ports which makes me think the water is coming in from below.

Thanks for the help.
Engine is a PV900 4mil but that should not matter.

 

[Mooh]

I had same issue before,
the water was moving to the cylinder when I tried to start the jetski up the trailer without moving.

 

[Mooh]

and also i changed the the water jet for the exhaust to smaller.

 

[loictahiti]

and also i changed the the water jet for the exhaust to smaller.

What kind of exhaust you have ? RRP , TNT or PF .
And size of waterjet you choose ?
The problem still running or this change fix it definitly ?
We have same problem here in Tahiti on 2 Dasa 1055, one with PF exhaust with injection and 9ne with RRP carbon pipe .....

 

[Cruiserfj40]

Still stumped.

As of now if blocked if cooling and ran it with 60 psi if air pressure. It held the Pressure.

I put water with Uv dye in the blocked off cooling system then pressurized that. I couldn't see any definitive leaks. Fuel and oil mix does show up a little green with uv light so maybe I just couldn't tell the difference.

Hooked cooling system back up with no exhaust water. Engine has now sat for two weeks. I ran it for a minute till couplers we're getting hot then pulled power valve and saw some water drops and milky build up.

Hooked up water to exhaust and ran it longer. Had more build up on back cylinder. Here are a couple pics of the front and back pv's. Front looks fine to me. Rear gets build up toward back of engine.

 

[Quinc]

Run it until it is hot and then try pressure testing it? Might be a small crack that opens up once it gets hot enough.

 

[Cruiserfj40]

I ran it with pressure on the cooling system till it was as warm as I wanted it to get with no water. Didn't see any kind of pressure drop. When it was pressurized with water in the closed off cooling system pressure went up as it got warm then dropped back when it cooled off. I would expect that to happen though.

I let it sit with pressure on it overnight and it did bleed off some but the head was seeping just a little where the oring was bonded. And overnight it went from 60psi to 45. The amount of water getting in I would assume is a larger leak than that.

 

[zzylstra]

Billet cylinder?

 

[Cruiserfj40]

yes.

 

[Quinc]

Did you figure it out?

 

[Smokey72013]

Did this issue get resolved? Anytime where whater is getting into a 2 cycke watercooled engine always suspect head or head gasket first. With the milky stuff in the motor id think it was surly bigger then a 15psi drop overnight. But if it is a headgasket leaking compression could be lifting the head and letting water in. Could be a crack in the sleeve or waterjacket somewhere.