cylinder head temps

[peter Laforce]

93 115 that has one cylinder head hotter than the other side, changed the thermostats and still the same?

[TownsendsFJR1300]

93 115 that has one cylinder head hotter than the other side, changed the thermostats and still the same?

Is the engine run in salt water and flushed REGULARLY?

What temps are you getting on each side(I gather with a lazer temp gun pointed at the same spot on each head) or just by feel?

[peter Laforce]

just by feel an it is run in saltwater but flushed after every run?

[boscoe99]

If you are not getting an over temperature alarm what's the problem?

It is not abnormal for one cylinder to be hotter or colder than another cylinder or for one bank of cylinders to be hotter or colder than another bank cylinders.

Airplane piston engines can be equipped with cylinder head temperature sensors and exhaust gas temperature sensors. One for each cylinder. The temperatures are almost never the same. It is rare when they are the same. If they were ever all the same then that would indicate that something is wrong with the temperature indication system.

[TownsendsFJR1300]

just by feel an it is run in saltwater but flushed after every run?

Flushing everytime after salt water use, absolutly, from Yamaha;

https://www.youtube.com/watch?v=ZJaTjMOEKP0

There are many threads here with the heads/water jackets clogged up with solid salt causing overheat issues.. The salt water drains out of a hot/warm engine and solidify's. I personally (have a boat lift on a brackish canal), as soon as I get the boat started up on the lift, get water into the powerhead connector(not running). 10-15 minutes of that, then I run on the muffs for another 10 minutes. (we have re-claimed water so the amount of water is the same $ no matter how much I use).

But you get the idea.. A couple of minutes flushing WILL pay off down the road with little to no clogging issues/overheating etc.

As Boscoe noted, if its not overheating, your probably fine.


I have personally, on my neighbors 200HP, 2 stroke, Yamaha pulled the heads as it was ovedrheating and shutting at 4,000+ RPM's. The lower cylinder water jackets were 95% clogged with salt (about 3.5" deep). I don't know how the engine ran as well as it did. After cleaning, it ran to WOT without any alarms, shut downs, ran like a top. The overheat sensors, on that engine happened to be located towards the lower cylinders. I suspect Yamaha put them there, for that reason.

He flushed once in awhile, the PO of the engine, don't know.