engine and power shuts down

[soupy]

I have a 06 launch 350 and I have been running it without any issues but yesterday I fired it up and at idle it cutout twice. then I took off and was under full power and the engine quite and the power (dash) shut off and came immeditaly back on. this has happend a couple times more. then later on I had a 40 min run at full power and not problems..I have checked battery terminals and they are tight..one friend said he thought it could be a vapor lock from not running the blower long enough...but that to me does not explain the loss of power...that seems more like a short...hoping someone might have any suggestions ?

thanks Chris

[SquamInboards]

Check your safety lanyard... wiggle it with the key on, see if power to the dash cuts out.

[RBabbitt]

I have a 2009 24V Sunsport with a 350 Indmar engine. When I was using the boat last week, virtually the same thing happened to me. Like you, Chris, this had never happened before- and I purchased the boat new in 2010. I was cutting the speed (coming into a dock after operating from full throttle) as I approached a no-wake zone. The boat had been running flawlessly. When I decelerated, the engine cut out- and the engine fault light came on. I sat on the water for about five to ten minutes and it fired up and worked fine until I got it to the dock and let off my passengers. I took a tow back to my dock. I ran it again the next day to see if the problem was continuing. Again, when I started it up it idled properly for about ten minutes. After that, I took it out and ran it at full throttle. Initially, it ran perfectly at full throttle but it cut out and died (again showing the Engine Fault light) when I came off the throttle. This time it took me a few more attempts (after sitting for about five minutes) to get it restarted. When it did, instead of idling at around 750 RPM's- it ran rough at around 450 RPM's before it would cut out. I docked it, and started it up later that day and it seemed to hold a constant idle (750 RPM's) and run at idle speed without any problem. Due to time constraints- and my desire not to get stranded on the lake- I did not take it back out to see if the problem was continuing- but I would bet that it is. I will check the lanyard on mine (good idea)- but the engine fault light suggests to me that it is not a power problem- at least in my case. Any ideas would be greatly appreciated. Robin

[sailnaked6842]

Given the year of the boat you may have to pull it out and take it to a dealer who can read your codes because there's too many things that can do this such as a bad connection somewhere or maybe even a malfunctioning O2 sensor. Good news is it sounds like the engine is okay just some supporting device will need to be replaced, although I would tend to lean away from suspecting the lanyard on this one.

[RBabbitt]

Great idea. Anyone know an authorized dealer near our place in Vonore, TN? I think Shadrack Watersports closed their Knoxville location and I'm not sure to take it where they can read the codes. Robin

[SquamInboards]

Given the year of the boat you may have to pull it out and take it to a dealer who can read your codes because there's too many things that can do this such as a bad connection somewhere or maybe even a malfunctioning O2 sensor. Good news is it sounds like the engine is okay just some supporting device will need to be replaced, although I would tend to lean away from suspecting the lanyard on this one.

Agreed that this sounds more complicated in this case. Intermittent electrical problems are the worst!

A few years ago I had an issue where my engine would shut off randomly - and I don't even have a safety lanyard - it turned out to be a single loose connection on a main breaker on the engine.

[RBabbitt]

Thanks for all of the advice. I located a Supra dealer who is sending a service person to my dock on Friday to run a computer diagnosis. I'll keep you posted when I figure this mystery out . . .

[pridekit]

Sounds like a loose wire somewhere, possibly a ground. Scanning the computer is a great place to start, any mechanic or dealer that has the diacom software or techmate should be able to read and clear codes (they need to use the CAN adapter). On my motor (06 Launch 21v w/ 325HP Indmar Assault), the major grounds can be found on either side of the transmission (big silver/gray device attached to the motor that has a black cable connected to it to control shifting). On top of the transmission is a metal plate that holds the computer and relays, as well as the circuit breaker (big red button on the side), this is also where the diagnostic port is (10 pin connector I believe). If you follow the plate down on either side you should see where it mounts to the engine, you should also see some wires here. I removed mine and cleaned up the bolts and terminals, this helped resolve an intermittent starting issue I was having.

[Swamplandkarl]

I can read engine codes on my 2010 20v on the supra vision, look in the menu.. I don't know if the 2006 model has that option...

[pridekit]

I can read engine codes on my 2010 20v on the supra vision, look in the menu.. I don't know if the 2006 model has that option...

The 06 doesn't have vision, it's just analog gauges. I've been tempted to look into adapting the vision system or creating one from the same base as the vision (murphy helmview).