2000 15hp 2 stroke not peeing in gear

[memphisrm]

Hello,

I have a 15hp 2000 2 stroke. I replaced impeller and pump housing because I had some water in my oil and thought that maybe I had a a bad seal or leak (and it was time for a new impeller anyway). Now the motor pees great when in neutral. If I put it in gear with just a little juice the stream weakens. If I crank it up the stream stops completely and smoke comes out. My first thought was that the impeller key was not in place so I took her apart and it is securely in place.

One shop that I called suggested that I may have the impeller in backwards (not sure if they meant that it was upside down or that the fins are facing the wrong way). Can this cause the problem I am describing?



I am stumped! Does anyone have any suggestions? I was hoping to have it rocking for a trip this sat-wed but it is starting to look like I am in hot water. All the repair shops around here are backed up 2-3 weeks.

Thanks in advance for any suggestions!

[Ski]

The only things that come to mind is the O-ring atop of the impeller cup. Is the water tube in the exhaust housing have a bad seal?

[memphisrm]

??? o ring ???

Thanks for the feedback Ski!

I don't know much about motors but I don't think I have an "o ring" in my impeller assembly. I do have two plastic washers and one is missing but a local tech said that there is no way that that could be the problem.

I am attaching a video. In the beginning I have the motor in gear but not a lot of juice going in. It is a little hard to see but towards the end I increase the throttle and shoe that the pee stream goes from a strong solid stream to bits of of water here and there.

The same tech said I should check for blockage so I dropped the lower unit and modified my water hose to attach to the pipe that fits into the impeller housing and flushed it out. No luck.

I was told to check the thermostat - according to my serial number (0T056956) this diagram (3234 M Mercury Marine 90 Cylinder Block and Covers Diagram and Parts) I have one and - but there is not one there.

Another tech suggested a "poppet valve" aka a "pressure release valve" that opens around 1500 rpms. I cannot find said valve in the boats.net diagrams.

I've checked the impeller assemble 5-6 different times.

Help?!?!

Thanks!

[Ski]

The thermostat P/N is 14586 (120*) It look to be the same picture on boats.net #37, Did this work OK prior to being worked on?

[memphisrm]

Thanks again for the reply and info

There is no thermostat in my motor. I see that there should be in the diagram but when I remove the thermostat cover (item # 34 in the diagram - link below)
there is not one there. I bought the motor used right at 12 months ago and it has been running fine. I have had no problems whatsoever until I noticed some water in the oil. After seeing the water in the oil I decided to change out the lower unit gaskets and impeller (I ran though a shallow sand bar and some was sucked up into the motor) and figured that it was time to change it anyway.

That is when the problem started.

Does anyone know anything about a poppet valve? Could that be my trouble? If so, where the heck is it?

Thank again for any suggestions. I hope to get this joker working again soon!

3234 M Mercury Marine 90 Cylinder Block and Covers Diagram and Parts