1999 ox66 sx200txrx water temp

[rolrandy]

1999 OX66 sx200txrx what is the normal operating temp the motor should run at and what temp does it go into limp mode?

[rolrandy]

More info
Motor went into limp mode temp gauge reading was 170 motor cooled off quickly and was fine.
heads cleaned maybe 100 hrs prior tstats new so I thought i'd change the pop-it valve, it looked fine but I changed it.
next outing it ran fine temp gauge ran up to maybe 200 didn't go into limp mode. took a laser temp scanner and hightest temp I could read was 130 various spots on the head both sides .
So my question was/is what temp does the motor normally run at and what temp does the motor go into limp mode?

[99yam40]

what are the temp switch specs in you service manual?
that should give you a clue when they should send a signal it was overheated

[rolrandy]

have a yahama service manual only thing I could find in it was thermostat start open temp and full open temp which was 140 f
the temp gauge is an aftermarket add on

[99yam40]

keep looking, it has to have the specs for the temp switches that tell the CDI or ECU the heads/ block they are too hot
some motors have temp sensors also. not sure what yours has

where is this aftermarket gauge taking readings from?
If not from the same place as the temp alarm switch area, they may not be seeing the same temp

[fairdeal]

the temp switch will trip >185 or so

but as 99yam suggests,
there is also a temp sensor -
perhaps in a different spot;
and if it can trigger overheat,
perhaps at a different temperature than the switch.

Boscoe may have that detail.

[rolrandy]

The aftermarket gauge has a elec sensor screwed into a blind hole on the head no actual water touching it .

[rolrandy]

fairdeal looking at the numbers the switch comes on at 194 and motor goes into limp mode correct?

[boscoe99]

The thermoswitch is designed to close from 183* F through 194* F. If and when the switch closes the warning horn should sound, a light or an icon on a Yamaha tachometer should illuminate and the CDI assembly will put the motor into RPM reduction mode.

It is not a limp mode. Continue to run the motor while thinking that it is limping can cause great harm.

[boscoe99]

the temp switch will trip >185 or so

but as 99yam suggests,
there is also a temp sensor -
perhaps in a different spot;
and if it can trigger overheat,
perhaps at a different temperature than the switch.

Boscoe may have that detail.

I don't but my suspicion is that the thermosensor will not, repeat will not, trigger an over temperature alarm.

[boscoe99]

The aftermarket gauge has a elec sensor screwed into a blind hole on the head no actual water touching it .

If a Yamaha temperature sensor were to be used it screws into a port on the top of the cylinder head. Directly into a cavity in which water is flowing.

[Keithbaja]

Most outboards are 143 to 163 anything above that and the salt crystallizes. LOL I don't think I've ever in 60 YRs ever typed that word.....also there a temp sensor for the wcu/CDI unit and a heat sensor near the top of any head or heads