2001 0x66 SX250TURZ CDI Issues Keeps Popping Into Limp Mode

[bonafishark]

Thanks for reading, long time viewer, this site has been extremely helpful, hats off to the guys who help us in need.
The issue I am having is that the engine keeps popping in and out, mostly in, of limp mode with fixed and retarded timing and RPMs of 1100 and no spark to No 6. Zero throttle response when this happens, dead in the water.
Engine will warm up normally and when getting I'm ready to leave the slip, she will pop right into that limp mode. This happens whether the boat is in gear or not. This points to a sensor failure, ok, I have done the following:

TPS has been checked and is at .50volts at idle and increases smoothly with throttle opening up to 5 volts. Also getting 5 volts at the orange and red.

Crank position sensor has been replaced with a brand new Yamaha CPS, this was my first suspect as I had one go bad before and was replaced with a working used one.

Water Temp Sensor has been checked and is in spec with what the manual states, spot on at the 41, 68 and 212 degrees, tested half dozen times.

Air Temp Sensor has been replaced with a known working one

Air Pressure Sensor has been replaced with a known working one, both test out at 2.14 volts, though manual states should be 3.2-4.6 volts.

O2 sensor has been cleaned and checked and is within spec, dont think this sensor effects the limp mode.

Knock sensor has been replaced with a known working one, again dont think this sensor effects limp mode.

I have tested the sensors both when in limp mode and when not, test results are the same, no difference.
I have also checked the Tstats and have checked the thermo switches as well. Alarm system is working. I have redone all of the grounds, I have been through the harness a few times and have replaced some questionable connections. The limp mode yellow wire connection has also been replaced.

What I can remember is right before this whole issue started, I noticed a drift in the RPMs, for example when I was throttling up and than throttle held steady, there would be a slight drift up. When throttling down, same thing once held, drifting down. Funny thing is after this initial problem, the CPS was replaced and the boat ran fine for a few hours before going limp.

I guess my question is, is there something I am missing here? Are the TPS, CPS and WTS the only sensors that will default the CDI into limp mode if nonfunctioning? Is there anything to gain by purchasing a winky blinky? Could this be an internal CDI issue? Unfortuantely, I do not have one to swap.
Thanks in advance!

[bonafishark]

Also, injectors were sent out for cleaning and testing approx. 200 hours ago, compression is 115-120 across the board.

[ausnoelm]

To be honest, I don't think any of t hose things will put it into "limp" mode, no oil or over heat will sound an alarm, and reduce RPM, I think you need to lose the tunnel vision and do some proper trouble shooting, or take it to someone who knows what they are doing.

[rodbolt17]

when checking sensor outputs,especially on 3 wire sensors, ALWAYS test the reference voltage.
loss of the #6 pulser coil or the pulser ground can shut off #6 and set a code 13 and lock base timing ang once that code locks timing wont advance.

[boscoe99]

To be honest, I don't think any of t hose things will put it into "limp" mode, no oil or over heat will sound an alarm, and reduce RPM, I think you need to lose the tunnel vision and do some proper trouble shooting, or take it to someone who knows what they are doing.

He seems to be confusing the Yamaha RPM reduction mode due to low oil quantity or over temperature (alarm sounds and the max RPM limited to ~ 2000) with the timing becoming fixed with an increase in idle RPM, due to a sensor fault.

The term "limp" is not a Yamaha term.

[bonafishark]

Thanks Rodbolt. I did swap the No 6 coil and still no spark on 6 when in 'locked' mode. Tried several coils and did the same thing, fires when all is ok and does not fire with locked timing.
I could not find a test for reference voltage on the APS in the manual, but will look further.
And yes I guess I am confusing the term limp mode with RPM reduction mode. The issue is not a RPM reduction mode issue from low oil or overheat.
Would a sensor fault trigger dropping the No 6 along with fixed timing?

[99yam40]

Thanks Rodbolt. I did swap the No 6 coil and still no spark on 6 when in 'locked' mode. Tried several coils and did the same thing, fires when all is ok and does not fire with locked timing.
I could not find a test for reference voltage on the APS in the manual, but will look further.
And yes I guess I am confusing the term limp mode with RPM reduction mode. The issue is not a RPM reduction mode issue from low oil or overheat.
Would a sensor fault trigger dropping the No 6 along with fixed timing?

what #6 coil did you swap?
pulser or ignition coil?
I read that Rod meant the loss of #6 puler coil or its ground

[bonafishark]

Sorry, ignition coil. I will direct my attention to the pulser coil. Thank you.

[rodbolt17]

notice I did not say IGNTION coil?

they simply rarely fail and if they do they are NOT monitored and WILL NOT lock base timing.

the PULSER coil is monitored and IF one fails it will LOCK base timing and shut down one ign coil.
the remaining injectors will fire by default.

the pulser coils feed information to the CDI for firing ign coils and injectors.

[bonafishark]

Turned out it was the Water Temp Sensor. Even though it tested just about perfectly within spec as per the manual, it must have still been failing at some point.
Pulsar coils were good.
Thanks for the help!