2004 Speedster 200 - one engine intermittently stalls

[IDoSeaDoo]

Hey guys,
Bought an 04 Speedster 200 with the twin 155's. It USUALLY starts and runs great, but two times, we had an issue where the right engine will stall when you put the throttles to Idle after running. Yesterday, we were running below planing speed, just plowing water. When I dropped to idle, right engine cut out and would not restart. I opened the access below the seat and manually opened the throttle, and it fired up, but would not idle. Because I didn't want to cut my day short, I used the adjustment on the throttle cable to make it stay running and continued the journey.

Later on, the engine caught up to the advanced throttle, and idled at 3500 at the lowest throttle position. I had to advance the other motor ahead to make RPMs even. It never stalled out again the rest of the day.

Plugs are new, and oil level seems just below the 3/4 full line on the dip stick. At one point in the day, the Tachometers freaked out and were showing RPMs about 3-4000 more than what the engines were doing. Restarting the engines fixed the problem.

Does't have the CEL, or any other lights on while running. I'm suspecting the idle controller, but wonder if anyone else had any such weirdness, and how they fixed it. Throwing parts at a problem like this can be very costly and wasteful.

 

[wrench2ride]

Did you happen to check the spark plugs to see if they were wet or darker than the other engine? it sounds like you may have an issue with your idle bypass valve or something stuck in the port for it, you could try switching them from one engine to the other to see if your problem switches engines, what ever you do don't push down on the plunger for the ibv you could damage the gear inside it. if you put it on the computer you could compare one with the other to see if they are operating at the same value or not, that would tell you if something is going on with it.

 

[IDoSeaDoo]

Is there any other alternative to Candoo for these engines? Something cheaper?

 

[gb387]

There really isn't anything else out there, you can always take it to a dealer and see what they think. I would guess it will take the dealer some time this time of the season to get your boat in and it may cost just as much as a Candoo investment... Just have to figure out what is best for you, the candoo won't fix the problem but will hopefully lead you in the correct direction.

Remember 'BOAT' stands for 'Bust Out Another Thousand'.

 

[IDoSeaDoo]

I love that I have two engines, so I can swap parts between the two. One thing I don't get is WHEN do you need to reset the TPS? Is it when you get a new one? Is it when you change the throttle cable position, or just when you modify the stop screw?

I'm afraid to take it to any dealer. 1: they'll charge me at least $100 to just look at it, and aren't guaranteed to get it right. 2. I've heard horror stories of guys spending hundreds and hundreds on parts and labor and STILL not get the problem resolved. 3. I'd rather learn how to fix it myself. I always learn so much other useful stuff in the process.

I would rather spend the money on a buds or candoo than pay some dealer, but I'd really like to have both engines hooked up and see what each is seeing at the same time. Also, I'd love to log it to excel or something. My $300 vw tool let me do that (and it worked on more than just 4 cars)