01 Optimax 200hp rough idle in gear

[SLambeth]

My 01 Optimax 200 will idle ok in neutral, but it will die when put in gear before it gets warm to normal temp. The serial number is OT371603.
I have replaced the plugs recently and it runs better, but has the same issue till it warms up. This is common after fishing for a while when the engine cools back down also.

Let me clarify- the motor idles rough before it gets warmed up to temp- 115F or so. If I try to shift into gear before operating temp, it typically will die. Any suggestions???

Thanks-Sean.

[Savage]

No. Check the shift position switch.

[SLambeth]

Savage, when it's warmed up- it idles fine and won't die when shifted. How would the shift position switch cause this when it's cold and not up to temp?

[SLambeth]

Bump.

[SilverFox579]

Pumping the bulb before every engine start? What is battery voltage prior to starting, at idle while running rough, and after warm up when it stops running rough?

[SLambeth]

I don't prime the bulb, it starts up just fine. The battery voltage reads 14 during startup and after it's warm.

[hstechfl]

Savage, when it's warmed up- it idles fine and won't die when shifted. How would the shift position switch cause this when it's cold and not up to temp?

The shift interrupt switch restricts fuel to 3 cylinders when shifting. There may not be a problem with the switch itself, but if your motor is struggling before warmup- the fuel restriction of the switch could cause the engine to stall when shifting. I would chase the rough idle problem, once corrected- the shifting problem should be OK.

[SLambeth]

I located the shift position switch and it looks like it operates normally. How do you check it? My shift position switch appears to be electric with a small button that is depressed in neutral and extends when in gear.

[Savage]

Checked with a CDS or DVOM.

[SLambeth]

Savage- what is a CDS or DVOM?

[hstechfl]

Savage- what is a CDS or DVOM?

DVOM is a digital multi-meter, which you can probably get. I'm guessing its a resistance test, but not sure about the numbers since the manual does not specify. Hopefully someone who knows will chime in since I'd like to know too!

[SLambeth]

Thanks, if anyone knows what the resistance should be?- I can get to the connections easily.

[Savage]

CDS is a Dealer tool. Computer Diagnostic System

[EuropeanAM]

Resistance is simple on the shift switch.

CLOSED circuit (no resistance) in NEUTRAL.

OPEN circuit (infinite resistance) in gear.

I'm not convinced that it has ANYTHING to do with your complaint, though.

Have you verified your spark plugs are fully seating against the CRUSH RING, and are torqued to 20 lbs/ft? A damaged thread can prevent a plug from seating deep enough into the head...

Checked all of the basics? Compression, Spark, Fuel Quality, Delivery, and Air/Fuel Pressures (at idle, under acceleration, 5/10/15 seconds after shutdown)?

[GBhoss]

My old boat one did the same thing and it turned out to be the air pressure issue in the rail.

[SLambeth]

GBhoss- what did they do to fix the problem?

[GBhoss]

I had sent my rails and injectors to Don for cleaning and that is where the problem was found. If I remember correctly, I ordered new rails because the part that failed was non-serviceable.

[EuropeanAM]

I had sent my rails and injectors to Don for cleaning and that is where the problem was found. If I remember correctly, I ordered new rails because the part that failed was non-serviceable.

Up until a couple years ago, this was the case (replacement components are now available, allowing for repair of most anything EXCEPT CORROSION).

[hstechfl]

Up until a couple years ago, this was the case (replacement components are now available, allowing for repair of most anything EXCEPT CORROSION).

Don- was meaning to ask you about this..

I noticed on a most of the rails (and mine) there is a lot of corrosion or wear around the #6 socket (the bottom side where it touches the DI) on the port rail. Is this caused by something or is this general wear and tear? If air starts escaping from the port- I'm guessing it can cause rough idle, loss or power, etc. I wanted to replace mine as a precaution but cant find any used ones that are in good shape and the parts catalog says they are NLA.

[EuropeanAM]

It can.

Please be a little more specific on which component you think is NLA... unclear from your comment.