Bad cavitation as well.
First I want to thank you guys. I have used this forum to learn how to…and fix several ski’s. I have hit one that is over my head. I hope this is not a repeat question. For the last 3 years I have been training myself on repairing ski’s with fair success. I am lost on this one.
Customer brought in an RXDI ski, 2003. It had serious cavitation along with a maintenance alarm. I found that the pee stream from the front showed an inconsistent stream and the maintenance alarm was tied to that stream. The ski shoe had a large hole blown in it. 1 inch wide and 2 inches long. Thought it was a smoking gun reason for the problem and changed the shoe. Did not fix it.
When the ski would cavitate, I could see air moving through the cooling lines.
First I thought the cavitation started in the jet unit and pulled the air into the cooling lines. I put caulk on the drive shaft where the orings seal by the wear ring. Ski worked perfect until it sucked the caulk through the orings. Figured I had it and replaced the orings at the wear ring. Ski went 67 mph, for about 10 minutes, then back to square one, alarms and bad cavitation. Put caulk there again and it was not leaking there.
Replaced carbon ring, no change.
Wear Ring and impeller are new.
I also found a leak in one tee of the cooling lines and fixed it. For about 15 minutes, ski ran flawlessly. Alarm went away and no cavitation. Pushed it real hard, ski cavitated and I was back to square one, could not get it planed out it cavitated so bad.
Rave on the exhaust was now leaking, replaced it, again, 10-15 minutes of performance and then right back where I was.
It feels like I am chasing a weak link. Something is causing the cooling lines to have excessive pressure or suction, as I fix a problem it moves.
I now believe that the air is getting introduced to the jet from the cooling system. I watch bubbles come in at the top of the exhaust pipe cooling line, move through the ski, come out the exhaust side and cavitation starts. The ski will alarm almost immediately from lack of flow in the cooling system. If I have a good pee stream, no alarm, no cavitation, as soon as I lose that, cavitation and alarms and visual air in the system.
Help at this point would be awesome.