2003 outback engine stall and high idle

[Dom08]

Hey guys!
Well with boating season here, I finally got time to run the boat in the lake.
After sitting for 7 months, fresh gas and the boat fired right up.
I ran the boat this weekend and found that my issue I was starting to have last season is still present.
What happens is if I run the boat at 20-30 in the lake towing a ski'er and I throttle down and kick into neutral that my idle of the boat will stay quite high. If I kick it into neutral and the idle stays high if I go into a gear (forward or reverse) in the state we get a big clunk as it kicks into gear.
The other issue I had this weekend is a new one. I was towing a ski'er at about 25 and all of a sudden the engine completely stalled out, all electronics were on with no disruption. I turned the key off, and the boat fired up with no problem and ran fine. In driving the boat now I am listening to everything and I get a very random stutter almost like a misfire, but I don't know for sure.

Last season I changed out the spark plugs and distributor cap as a maintenance.

Any thoughts on either of these issues?

Thanks!

[bergermaister]

Carbureted or fuel injection?

How are your throttle cables looking and return springs (if present)? Any play?

Do you have PerfectPass? If so, is the servo motor behaving properly?

Definitely do not put it in gear if it is revving high - unless you are looking for more to repair.

Mine completely crapped out one night while towing a surfer. But completely crapped out - not a single light on anywhere. In a pitch black section of the river... Turned out to be a slightly loose main wiring harness plug. You might check not only for tightness and fully seated plugs but pull them apart and look for any corosion.

My PP servo motor also crapped out last year and had to be replaced. The joy of older boats!

[Dom08]

Thanks for the reply

I'll have to take a look to to see if it's carb or TBI. I honestly haven't payed attention to it.
Throttle cables seem good with no sticking.
I do not have perfect pass

[Jimm]

I experienced the out of nowhere "conk out" a couple of years ago. At first it would crank right back up but it soon began taking longer & longer. Although there could be any number of underlying causes, turns out my issue was a bad fuel pump. Given the similar symptom, you might give it the once over to make sure. Good luck.

[Dom08]

I should mention my gas level was low but this was never an issue before.
I have never changed out the fuel filter I have owned it since 2018.
I'm going to bring a replacement filter with me next time I am at the cabin.

Is this located by the tank under the trunk? I have a water separator also at the front of the motor (left side).?

Or is that the fuel filter and I don't have an inline fuel filter ?

[Holdmybeer]

Carb engine I would check return springs on carb or vacuum leaks. Intake manifold leak will cause high rev idle and stalling.

Fuel injection I would replace the TPS (throttle position sensor).

[Dom08]

Is there any specific way we can test for a vacuum leaks or an intake manifold leak?