Busted Grouse
New Member
Great forum here, and rest assured that I did some extensive searching before this post. I'm just sorry I have to use it so soon.
Bought a 1995 Speedster last week. Ran like a top on a half-hour test. RPMs were good, got out of the hole quick, speedo read 55 MPH, all seemed well.
Last weekend, with a full load of fuel and 500 pounds of passengers, and with the engines warm I had trouble getting on plane. The starboard engine would start to cavitate at 4500 RMP, zipping up to 8,000. Finally got up on plane (slowly, with no cavitation) and headed down the lake at around 40 MPH. Five minutes later, the engine overheat alarm came on, so I shut down and I got a friendly tow back to the dock. I was able to restart each engine for a few seconds, just to make sure they weren't seized.
The ONLY change from the good test drive to the bad trip was that I pumped the old oil out of the reservoir, and refilled it with BRP Rotax 2-stroke mineral oil, as I had no idea how old or what type the previous oil was and had read all the warnings about mixing. And I topped it off with 87 Octane fuel. Didn't, however, drain all of the old oil out the lines -- just did the reservoir.
Any thoughts? Could the cavitation and overheating be related? Coincidence?
Bought a 1995 Speedster last week. Ran like a top on a half-hour test. RPMs were good, got out of the hole quick, speedo read 55 MPH, all seemed well.
Last weekend, with a full load of fuel and 500 pounds of passengers, and with the engines warm I had trouble getting on plane. The starboard engine would start to cavitate at 4500 RMP, zipping up to 8,000. Finally got up on plane (slowly, with no cavitation) and headed down the lake at around 40 MPH. Five minutes later, the engine overheat alarm came on, so I shut down and I got a friendly tow back to the dock. I was able to restart each engine for a few seconds, just to make sure they weren't seized.
The ONLY change from the good test drive to the bad trip was that I pumped the old oil out of the reservoir, and refilled it with BRP Rotax 2-stroke mineral oil, as I had no idea how old or what type the previous oil was and had read all the warnings about mixing. And I topped it off with 87 Octane fuel. Didn't, however, drain all of the old oil out the lines -- just did the reservoir.
Any thoughts? Could the cavitation and overheating be related? Coincidence?