Alarm - Johnson 1989 115HP 2T (Help Needed)

[CH1968]

All,
Just started my outboard (with ear muffs over water pump area) the first time in 18 months - after an extensive storage period of non-usage.
It ran fine up to 3 minutes - then an alarm sounded at the console and i turned it off. I do not know if this alarm was caused by overheating or another tigger…

- the fuel is new.

- water pump/impellor is new (installed just before layoff in 2008).

- new thermostats and confirmed they open at the right temps (installed just before layoff in 2008).

- cleaned out cylinder ports and removed all salt grime/buildup after removing heads.

- no cracks in cylinder heads.

- good / even compression from all 4 cylinders.

- fairly healthy water flow from piss hole.
- water does splash out from the propellor area.
- water supply pressure from tap not the strongest IMO.
- both heads were hot to touch.
- all water deflectors in block have been replaced and are not swollen.


Questions....

- best way to test ohms for temp sensors and in what type of oil bath?
- what temp/ohm triggers off the sesnors?
- how to determine if the water supply pressure is sufficient to prevent possible overheating?
- how to determine if this alarm is triggered by a strong vacuum in the fuel line or another cause?

- does a vacuum switch exist on this motor (if so where exactly)?
- where exactly are vacuum switches normally located on other motors?

Any advice on next steps to diagnose this problem would be much appreciated.


Cameron

[boats.net]

If it was a constant alarm probably overheat alarm and possible not getting enough water to engine through ear muffs. Try putting it in water first.
If the alarm was a second on and second off then it's an oil alarm, need to run on a 50:1 oil mix in gas until find problem with oil system to make sure engine is getting oil.