1974 140hp temp question

I have a recently rebuilt top end on this 4 cyl engine which according to the temp gauge runs at 185-190 degs . I also changed the temp gauge recently but not the sender. ....it is an automotive one not marine ( price was right) but I doubt this makes a difference. The old temp gauge was toast and had markings only ...no degrees on the face.

The temp is consistant so maybe it is the gauge?...are all senders the same?...maybe I should install the new sender?

I pulled the thermostat but can't read the temp rating on it so not sure what should be in there?

Does anyone know what is the normal operating temp for this engine and what rating thermostat should be in there ( I suspect 140 deg thermostat?)

Thanks

 

Temp senders are mated to the guages. I strongly suspect they are non compatable. I would suggest putting them to the boiling kettle test to see if they are compatable. At least you can see where boiling point is. Or be more accurate and use a thermometer.

 

Thanks Frosty...better yet I will install the new sender ( presuming the thread size is the same?) and see what happens....I bought a new 140 deg thermostat anyway ...for what it cost I will install it as the old one was rusty and crusty ( used on inland lakes in central Ontario....clean but high in mineral content)

 

You'lle be lucky, Ille be pleased if it does but shocked. I think it will be too long as well.

 

you mean the sender will be too long?.....

 

Probably,-- but I really don't know. Try it.

 

cleaned the old one up with CLR and it was indeed 140 deg with a date of 8,73 which I guess means it was the original....will pop in the new one in the spring,...