10 replies to this topic

[NamakagonResponse]

Looking for a little help! My tach is reading 1,000 at idle, last year it seems like it was lower, which made slow speed maneuvering, docking, and working around the skier/boarder much easier. This seems like the normal fast idle for a cold start, but it is not coming down from this RPM when warm, causing it to lurch into gear. The idle speed is consistent and is not fluctuating.

I have the 325hp fuel injected monsoon, 286 hours.

Two specific questions - one, can anyone tell me the spec rpm at idle? Two, how do you set/adjust the idle speed or is there something the should be bringing it down from fast idle that might not be working properly?

THANKS!!!!

[BuFootin]

Looking for a little help! My tach is reading 1,000 at idle, last year it seems like it was lower, which made slow speed maneuvering, docking, and working around the skier/boarder much easier. This seems like the normal fast idle for a cold start, but it is not coming down from this RPM when warm, causing it to lurch into gear. The idle speed is consistent and is not fluctuating.

I have the 325hp fuel injected monsoon, 286 hours.

Two specific questions - one, can anyone tell me the spec rpm at idle? Two, how do you set/adjust the idle speed or is there something the should be bringing it down from fast idle that might not be working properly?

THANKS!!!!

I have a 340 Monsoon, but your right, your idle is too high. My idle is around 700. Sorry, can't help you on how to adjust that. I'm thinking it's all controlled by the ECM, others more knowledgable on here will chime in.

[NamakagonResponse]

Talked to the dealer who says stabil can create this problem and since I have not added gas since last fall, he recommended I try running new gas through. He was 99% sure this would fix it. I'm going to try this and will post my results...

[SmoothWaterMan]

Does it run normally in the rest of the rpm range?

Idle is set at 650 by the ecm, and items that influence that will be the IAC, TPS, among other less likely ones (intake leak, fuel, etc)

Peter

[Oberon]

Talked to the dealer who says stabil can create this problem and since I have not added gas since last fall, he recommended I try running new gas through. He was 99% sure this would fix it. I'm going to try this and will post my results...

If that doesn't work check the throttle connections. A friend of mine had a similar problem and the issue turned out to be a corroded PerfectPass cable. It was binding and wouldn't let the throttle close all the way.

[NamakagonResponse]

Thanks Oberon and SmoothWaterMan. Yes, runs normally throughout the rpm range (up from 1000). Will check cables too and go deeper from there if needed.

[ORsurfer]

Interested to keep an eye on this. Have a 2005 with the 340 Monsoon and am having the same problem. I hadn't thought of the gas issue as our crappy weather still hasn't sent me to the pump. Sometimes putting into gear and back out will help resume normal idle, but it's hit or miss and seems to be independent of engine temperature.

The 2005 is a cable (vs. electronic throttle), but my rudimentary inspection suggests that the throttle cable is locked in place when the throttle locks into neutral, so I imagine it's somewhere getting bad information about mix/airflow/temperature. Looking for any suggestions/pics folks have to offer though!

[SmoothWaterMan]

If it runs fine above 1000 I would suggest you have a dealer plug in the computer and check the IAC position and possibly the TPS. Unfortunately you can't check these without plugging in.

Peter

[NamakagonResponse]

I got it resolved. I talked to the service manager at MN Inboard and he said he has seen two issues cause this as some of you have noted, one is the throttle cable, the other is that he said I need to look for a vacuum leak. I found a vacuum line that had become disconnected on the starboard side of the engine up top going into the valve cover. I reconnected this and started the boat and it idled at 650. Have not had it on the water yet, but think this did the trick. I will post again if the problem recurs.

The service manager thought the gas situation would NOT cause this problem, but I did also add fuel (91 octane non-oxy).

Thanks for the comments...

[Michigan boarder]

mmmmm.......Oberon......................

[Oberon]

mmmmm.......Oberon......................

I'm going to assume you are referring to the beer...otherwise it's a little creepy.

:D