Various Temp. Readings

[Jbear]

So I recently purchased a temp. gun and took some readings yesterday. I was only out for thirty minutes or so and running at 1500 RPM. I shot these temps.

Transmission Borg Warner: 78
Exhaust tube: 80
Heat exchanger: 167
#6 Cylinder measured at block: 192 (but counted down quickly to 178) was wondering if it was an issue with my fantastic Harbor Freight temp. gun?
Rest of motor shot at various locations was very close to 178 to 184.

I did finally run it at 2200 RPM but not for long. I know they are rated for more than that but just feel that 1700 to 1800 is where I want to be. There was no exhaust smoke and it ran great.

Just wondering if these temps were in line with what everyone else see's.
Motor is FL120, 1977 model.

Thanks,
Jeff

 

[DavidM]

Your temps look fine to me. A good place to shoot engine jacket temperature is at the top of the thermostat housing. It should be within 5 degrees of what the engine thermometer reads.

Another useful temp is the seawater hose just before the injection elbow. It should be within 20 deg of seawater temp measured at the strainer at load. Any higher indicates impeller or plugage issues.

David