2006 225 4stroke runs poor until warmed up.

[jerryjerry05]

2006 225 4stroke.
Starts right up but runs crappy for about 10-15 min.
Won't accelerate without missing.
Then when warm it smooths out and you can give it gas and it runs good.
Fairly new plugs, 175-180# compression.
Started and pulled each plug wire and each cyl. would drop until the wire was replaced.
No water in the gas, 2 inline filters: one by the tank the other under the cowl.

Any thoughts?
Thanks

 

[dingbat]

2006 225 4stroke.
Starts right up but runs crappy for about 10-15 min.
Won't accelerate without missing.
Then when warm it smooths out and you can give it gas and it runs good.
Fairly new plugs, 175-180# compression.
Started and pulled each plug wire and each cyl. would drop until the wire was replaced.
No water in the gas, 2 inline filters: one by the tank the other under the cowl.

Any thoughts?
Thanks

Did you check to make sure the thermostats are installed and or working?

 

[jerryjerry05]

No didn't look at the thermo's.
What to check on them? What tests?

 

[99yam40]

common sense would say , are they in place, and test to see if they open and close as your service manual specs state

 

[jerryjerry05]

Yam thermo setups are different than regular thermos .
They're hooked to a thermo switch assy.
Thought there might be some special tests for that part???
You do know how to test them don't you?

 

[dingbat]

Yam thermo setups are different than regular thermos .
They're hooked to a thermo switch assy.
Thought there might be some special tests for that part???
You do know how to test them don't you?

I see two normal thermostats and two plug in temp sensors.

Temps sensors would be checked by varying the temp and checking the resistance values where in spec.

I'm guessing a factory manual would give you the procedure and pass/fail values

 

[99yam40]

thermo to me means thermostat., (which open and closes to allow water flow)
not sure what you are calling a thermo, that has switches or other things tied to them

 

[jerryjerry05]

The thermo's are used in conjunction with thermo switches.
I don't have the manual, that's why I ask here.
Anyone have test procedures and values for the thermo switch's?
Thanks

 

[dingbat]

The thermo's are used in conjunction with thermo switches.
I don't have the manual, that's why I ask here.
Anyone have test procedures and values for the thermo switch's?
Thanks

Temp sensors are thermistors.

Check the resistance while varying the temperature.

Typically don’t go out of calibration per say. Typically fail open or closed.

 

[boscoe99]

Thermostats are used to help the block to warm up faster and to ensure that the block can come up to operating temperature in cold water. They are purely mechanical and are not connected in any way with the thermoswitches or the thermosensor.

The thermoswitches close if either is over heated. Closure of a thermoswitch sends a ground to the ECU. In which case the ECU will put the motor into RPM reduction mode.

The thermosensor tells the ECU the temperature of the block. The ECU then knows how much gasoline to provide via the injectors. It will also tell the ECU if it is over heated. In which case the ECU will put the motor into RPM reduction mode.

 

[boscoe99]

The thermo's are used in conjunction with thermo switches.
I don't have the manual, that's why I ask here.
Anyone have test procedures and values for the thermo switch's?
Thanks

How can you be trouble shooting and working on a motor without having the applicable service manual on hand?

Appears to me you are doing maintenance for compensation. Why are you depending upon the largesse of the Iboats community to help you in a commercial situation?

 

[jerryjerry05]

Bosco, none of your business what I do.
You don't want to help??? then don't read any of my posts and keep your opinions to yourself.
Nothing good to add?? add NOTHING!!

 

[JLarimar]

Thermostats are used to help the block to warm up faster and to ensure that the block can come up to operating temperature in cold water. They are purely mechanical and are not connected in any way with the thermoswitches or the thermosensor.

The thermoswitches close if either is over heated. Closure of a thermoswitch sends a ground to the ECU. In which case the ECU will put the motor into RPM reduction mode.

The thermosensor tells the ECU the temperature of the block. The ECU then knows how much gasoline to provide via the injectors. It will also tell the ECU if it is over heated. In which case the ECU will put the motor into RPM reduction mode.

Question, if the engine is hot after running will the thermo sensor send a signal to the ECU preventing the motor from starting?

 

[QBhoy]

Hi. Apart from the above (which might have given you an alarm perhaps), you may be losing the prime of your fuel system in the vicinity of the supply to or the VST. Meaning you are having to get air through the pumps and injectors for a while until it’s purged.
Or you may have issues like the suggested earlier or otherwise, that means your idle relief is active longer than usual…and/or she’s running rich in the mind that it thinks it’s cold

 

[dingbat]

Question, if the engine is hot after running will the thermo sensor send a signal to the ECU preventing the motor from starting?

This whole thing stinks of a temp sensor gone bad