GTX DI Piston Marking

[etemplet]

Just installed this engine and have 1/2 run time. Head gasket was leaking so I pulled the head and saw these marks on both pistons. I also had a film of fresh oil on the combustion areas of the head. I suspected that I had too much oil with the wrong setting on the pump which I didn't reset during the rebuild. Setting marks were lined up only problem is there are TWO marks. I did some checking in the repair manual and the pump adjustment is "spot on" where it should be. These pictures are 1/2 hour run time mostly idle to 2500 RPM in the water. 1st break in. This may be normal which I will gladly accept. Plugs looked a little dark but that's to be expected at idle for long periods and all the pump oil coming in.

Engine was a sluggish coming off idle which leads me to thin it is over oiling. I'm gonna take pressure tests for fuel and air and may run diagnostics with the Candoo just to be sure.





This was after I wiped the piston with a rag.

 

[mikidymac]

It does seem like quite a bit of oil for a DI.
Idling should be avoided with a fresh engine, you want to breaking in the rings.

 

[etemplet]

It does seem like quite a bit of oil for a DI.
Idling should be avoided with a fresh engine, you want to breaking in the rings.

I just make sure there are not hot spots and the water is flowing good and water is staying on the outside of the ski. I can put a good load on the engine plowing the hull under 3k rpm. I pretty much follow the SBT break-in procedure but have my own modifications.

I'll tell ya one thing... these engine builders ain't me. I never leave that ugly crap in the water jackets. My shiznit is pretty when I put it together.

 

[etemplet]

I'm gonna fix the terrible leak I have on the Water Control Valve and install some new spark plugs and MAYBE take it today. I'm dividing my time between the GTX DI and a Speedster that I bought last year. I'm posting about that in the Boat Section. Having fun !!

I ride with the seat off for the first break-in. I find some stuff doing that. I found a electrical plug getting hot on the last RFI I built. Damn thing ended up being a bad MPEM.

 

[etemplet]

947 Oil Pump Adjustment Youtube

I'm trying to verify the position for the oil adjustment on the 947 DI. There are 2 marks on the face of the oil pump. The Manual says to adjust it to the longest line. The lines on the 2002 GTX DI are the same length. As I mentioned I had to remove the head and there was a film of fresh clean oil on the combustion chamber. In my search I found this interesting video on Youtube. The guy says the "rich line" is for break-in and the "lean line" is for normal operation after break-in. (I am paraphrasing) I am going to do more checking. I'm gonna take the ski out again for a 45 minute run and see how it does. I don't see where anything I've done will result in less oil into the combustion chamber. I might split the difference between the marks on this DI. We'll see. I'm gonna post the video in it's own thread which will help people find it easier. Touchdowns everyone !!

 

[Boyd12]

"The guy says the "rich line" is for break-in and the "lean line" is for normal operation after break-in. (I am paraphrasing)" I have never heard that before! I was told the line on the right was for weekdays and the left was weekends. I feel so stupid!
Below is where I set mine. It ran well with no issues, but I didn't keep it long after this photo was taken. It may have grenaded later! lol

 

[WaarrEagle]

"The guy says the "rich line" is for break-in and the "lean line" is for normal operation after break-in. (I am paraphrasing)" I have never heard that before! I was told the line on the right was for weekdays and the left was weekends. I feel so stupid!
Below is where I set mine. It ran well with no issues, but I didn't keep it long after this photo was taken. It may have grenaded later! lol

View attachment 63014

Your photo matches how I set my 2000 GTX DI. The 2000 SeaDoo Service Manual actually does not have a photo, but the 2002 version does and it matches what you show.

 

[Boyd12]

I just make sure there are not hot spots and the water is flowing good and water is staying on the outside of the ski. I can put a good load on the engine plowing the hull under 3k rpm. I pretty much follow the SBT break-in procedure but have my own modifications.

I'll tell ya one thing... these engine builders ain't me. I never leave that ugly crap in the water jackets. My shiznit is pretty when I put it together.

"I'll tell ya one thing... these engine builders ain't me. I never leave that ugly crap in the water jackets." Agreed. I spend time cleaning areas no human will ever see.

 

[DI_Hoss]

(oil pump)

Riddle me this - how in god's name would one get back to the oil pump to even think about checking where it is set once the engine and exhaust are back in their rightful places?

Thanks for the write up folks - I got me a 951 to rebuild over the winter, and all the tips and tricks help!

Cheers!

 

[WaarrEagle]

With an inspection mirror - Telescoping Mirror

 

[etemplet]

I see I never put the proper closure on this thread. The rave solenoid lines were hooked up backwards because I installed the rave solenoid backwards. The ski was getting too much air at idle and very lean then when the raves should have opened all the way they were closing. That was some trouble shooting right there. LOL Good data... so the Di with the raves not working will hit 6200 rpm. Ski ran great when I reversed the rave solenoid.

NOTE: I remove the rave solenoid when I pull the engine on the DI. I've broken one of the little tabs previously and those solenoids are getting scarce and expensive.