Yamaha F150 Running Temps

[shoresls1]

Looking for people that have digital running temps on F150's using the interface cable and a MFD..like lowrance garmin or simrad.

I could be chasing a problem that doesn't exist or I am missing something. No alarms and engine runs like it should. 200hrs on 2006 f150. Hits 6k rpms with moderate load. 21' deck boat. However, I have been watching the engine temp on my simrad and it shows temps that I think are "out of line" and just seem to continue to rise the longer or harder it is run. I'm not arguing the actual # is wrong, yamaha never meant for it to be an actual reading, but the continual climbing has my attention. I'd like some input from others that have some info on digital extended running temps, if they climb or stop and hold.

My understanding is the engine temp thermo is 266 before alarm, this is where temp for the gauge gets read. The water temp switch is 186 before alarm. I have seen 225 and 232 on engine temp thermo. This takes about 10 min of straight running upper 4k range. I run out of room. Back down and it cools off. It's slow to rise and slow to fall. 2k rpms and 180 or less forever. I can run 4k rpms and it seems to hold 207/8. Again, I run out of room at that rpm. It might very well just get hotter the longer it ran. Thermostat and impeller are new with the same results. If I have some of this info wrong please advise.

[pstephens46]

Sounds about right. I measured a little less with the laptop connected to motor.

[shoresls1]

It seems to me that a 30min run at speed would overheat at this rate. Maybe I'm wrong?

[boscoe99]

What do you mean when you say "I run out of room"?

When you say that it is "slow to rise and slow to fall" that is normal. It is the block that is heating up. That is a large mass. It takes time to heat a large mass and time for a large mass to cool down. Water temperatures on the other hand can rise and fall much more quickly.

If you run the motor at WOT for 15 minutes or so I suspect that the block temperature is going to stabilize at some point. Maybe at 260* degrees F. As long as it is below 266* F there is no problem. I suspect that Yamaha has built in a fudge factor in as well. That is, the block will withstand a temperature higher than 266* F without the engine being damaged.

I suspect you are chasing a problem that does not exist. There is a reason that most engine companies don't want actual data displayed. Much to much of a deal is made of it. Folks have been known to complain about one engine running 2* F hotter than a sister motor, thinking that the hotter motor is having, or is going to have, a problem. When in fact it might be the cooler running motor that has the problem.

[boscoe99]

If it makes you feel any better, know that many aircraft piston engines have cylinder head temperature limits of 400* F. An F150 at 266* is running very cool compared to the aircraft motor.

[shoresls1]

What do you mean when you say "I run out of room"?

When you say that it is "slow to rise and slow to fall" that is normal. It is the block that is heating up. That is a large mass. It takes time to heat a large mass and time for a large mass to cool down. Water temperatures on the other hand can rise and fall much more quickly.

If you run the motor at WOT for 15 minutes or so I suspect that the block temperature is going to stabilize at some point. Maybe at 260* degrees F. As long as it is below 266* F there is no problem. I suspect that Yamaha has built in a fudge factor in as well. That is, the block will withstand a temperature higher than 266* F without the engine being damaged.

I suspect you are chasing a problem that does not exist. There is a reason that most engine companies don't want actual data displayed. Much to much of a deal is made of it. Folks have been known to complain about one engine running 2* F hotter than a sister motor, thinking that the hotter motor is having, or is going to have, a problem. When in fact it might be the cooler running motor that has the problem.

I run out of water to continually hold it. A no-wake zone or arriving where we are going occurs. However, I have a trip coming up and it's potentially 40 miles of on-plane running each way.

[pstephens46]

It’s fine. Certainly, run it hard and long. You only have 200 hours on a 2006 motor. Run it for God’s sake! Like a horse, it wants to run. Damn horses...