951 GTX RFI and DI engines?

[seadoosnipe]

In the last week or so, I've come across a few of our forum members who have had bad luck with the engines giving way with a short amount of running hours. I'd like to solicit the opinion of others who run this Rotax engine, either the direct injected or rotax fuel injection, to see what your thoughts are on the performance, longevity, and any other problems, big or small that you have faced while owning this model ski.
I hope to be able to use this information in the future with questions that pertain to bogging, low acceleration, and overheating issues. Thanks for all of your input!.................:cheers:

 

[lrs97gst]

2003 rx-di motor gone bad...q's and help

first of all i'd like to say hi (since i'm new here) and a for front thanks to all that help me in this thread and future threads.

back in july, with about 120 hours on the clock, my 2003 rx-di's motor dropped compression on both cylinders to 90psi. my father and I took it to our mechanic who is a licensed sea-doo mechanic who had previously winterized and summarized it. after pulling the rave valves and inspecting them and the cylinders, it was clear that the rave valves had touched the pistons causing the piston rings to snap. it seems as though the 951 di motors are starting to become notorious for failure especially after some research and seeing the sticky just above this thread about it.

the questions are:
1. what could the engine failure be due to? faulty oil pump, injector issues, ecu issues, or mechanic error during winterization and summarization?
2. i looked at sbt, and to get a new premium motor with warranty is 1800 plus core yada yada, is this the only company that offers new motors? i hear such great things about this company, are they worth it and reputable?
3. is it worth it to replace the motor? meaning is it likely to happen again?
4. is there anything that can be done to prevent this early hour engine failure?
5. sbt offers an engine removal and installation how to...are there any other how to's available?
6. is this something that can be tackled by a proficient mechanic? i have worked on various cars and done some minor to major work on them.

sorry for the long post, but i want this thread to help me as well as other's who might experience this problem. please keep on topic and answer the questions. thanks again for your alls cooperation and knowledge!!

 

[seadoosnipe]

Questions?

Sorry to take so long to get to your post.
Your questions are good ones. On my 787, my pto RAVE had a small nick on it where it had touched the piston. It didn't seem like to bad, so I just smoothed it out with a little wet & dry sand paper. I'm getting an average of 127 psi compression on both cylinders, so I'm not to worried about the damage.
The guillotine slide valve has a stop point manfactured that way to keep it from dropping to far into the cylinder. Question for me was, did it actually touch the cylinder or did something fall into the cylinder when the plugs were removed?
I think taking a look at your oil pump and what it's flow volume is would be a good first step in trying to figure what went wrong. If the volume isn't up to par, maybe dis-assemble the pump to look at it to see that it's still cammed to the engine.
Replacing the engine with an SBT engine? I don't know of anyone saying that they bought a bad engine and they didn't stand up to their guarantee. The problem with buying the engine is that your buying just the short block, so if your problem is in any of your other systems, i.e. oil pump, etc..., then your bound to encounter the problem again. So it is important to figure out why the engine went.
I made the post with the sticky because there seems to be a few forum members who have had some bad luck with the 951 but out of all the PWC's sold with that engine, I wouldn't say that it is out of the norm. In almost everything built, you can expect a percentage of failure.