Yamaha 150 Ox66 Operating temp

[Bangstick310]

What would be the normal operating temperature of this motor at idle and running?

I started the motor and had it running in a barrel for a decent amount of time to try and get to operating temperature after the winter sit.

The starboard cylinder bank temperature was floating around 120 to 130 ish and port side cylinder bank was low around 70 but seen temps get higher to aroun85 90/ Is this normal, I replaced thermostats ,water pump, had injectors cleaned, fuel filters replaced, poppet valve inspected. etc. water peeing very strong. The only thing i didn't do was replaced plugs yet. what would cause low temp? should i be concerned?

Thank you in advance

[99yam40]

never heard of anyone measuring the temps and reporting what they were,
but I have read of one side being warmer due to circulation paths or something else.

if you saw a lot of scale build up when changing the stats, you may want to use a chemical descaler to clean up the passages.

[Bangstick310]

never heard of anyone measuring the temps and reporting what they were,
but I have read of one side being warmer due to circulation paths or something else.

if you saw a lot of scale build up when changing the stats, you may want to use a chemical descaler to clean up the passages.

what do you recommend for descaler ? also was thinking about doing a salt away treatment. worth it or not ?

[99yam40]

I have read about Rydlyme before, but have never used it.
I thought saltaway was a preventative measure while flushing not a descaler of heavy deposits.
but I know little about these things

[DennisG01]

Rydlyme works very well. So does Phosphoric acid (concrete etch at HD) and "heavy" vinegar, also at HD (about 30%... regular vinegar is less than 5%).

[zenoahphobic]

Not saying descaling is not a good idea, but I gather this engine is not overheating, rather under heating.
This can only come about by excessive (cold) movement of cooling water. Other than fully opened (or non existent) thermostats , more greater water circulating can occur if excessive internal corrosion or gasket failures leading to bridging across of water passages has happened.