VF250 SHO overheat alarm

[MCPathfinderUF]

Good morning all. 

I have a 2018 22 Tournament with a 250 SHO. This weekend I was running the boat, jackplate about mid way down running around 4800 rpm and then the overhear alarm came on and dropped the revs down. I checked the temperature readout on the Yamaha gauge and it was at the mid mark. This has happened several times now.  Always checked the motor and peeing strong  I thought the SHOs had more water pickup down low?

I plan on having the dealer look at when I bring in for the 20 hour service but has anybody else had the alarm come on inadvertently?

thanks in advance 

[JEM]

Usually the jack plate is "down" in the normal position, not "up."   Does the alarm sound if you are running with the jack plate all the way in the "down" position?  The SHO does have a low water pickup.  Sometimes, the amount of water peeing out can be deceptive, especially if running at high rpms.  Does the alarm eventually quit after the rpms automatically drop, and you come off plane?  If that is the scenario, it would suggest that the engine is starving for enough cooling water at higher rpms.  My alarm will sound if I run my jack plate all the way up and run for more than a few seconds at high rpms.   It simply is starving for enough cooling water.   I would question how high the engine is mounted, and if the jack plate is mounted at the correct level on the transom.  If all this is correct, then you could simply have a defective sensor. 

[blackacre]

Do you have a water pressure gauge? If not, I would suggest adding one. You want to keep an eye on water pressure, especially when you have it jacked up.

Also be mindful of floating grass. Grass will clog you intakes and cause a motor to overheat. Did you tilt the motor up to check you intakes?

[MCPathfinderUF]

Thanks for the feedback. I actually have questioned the height of my engine mount since I got the boat since it seems very high. When I came off plane when the alarm went on I hit cancel on the alert on the Yamaha screen and looked at the engine temp gauge which was only at 1/2 bars which I wouldn’t think it would disipate that quickly if it truly was overheating. I agree that I do need a water pressure gauge do they have one that interfaces with the Yamaha gauge?  I plan on having the dealer check both engine mount height and the sensor when I bring in for 20 hour service and until then I will be extra careful. 

Also will get them to install WP interface  

 

Blackacre the grass is a problem too but was not bad this weekend and I did check the intake. 

 

Thanks guys

[JEM]

Does it alarm when you run at high speeds with the jack plate all the way down?  Generally, the jack plate does not need to be "up" much, if at all, during normal running.

[MCPathfinderUF]

I think that may be part of the issue I am still getting used to the jump from flats boat to bay boat and I may not be extending all the way down during normal operation. I am going out again Friday and will be more mindful and see if it happens again. 

What threw me off was when I came off plane during the alarm the temperature gauge showed right at 1/2 which would suggest the engine really wasn’t overheated  

Thanks again for the replies. 

[bernieNC]

The boat being new I would assume the jack plate and motor were mounted at the factory and they would know the correct mounting height. 

[MCPathfinderUF]

BernieNC completely agree with you!  If anybody is going to know the correct height it’s them!

i am going to do some investigation when I get back on the water end of this week. 

Thanks

[hurricane]

Keep in mind the warning is gonna sound a good time before the motor temp is actually in an overheat condition. New motors might even be smart enough to see a rapid rise and sound before it even gets anywhere near overheat.  However, you shouldn't be getting it, so best to figure out whats going on. I'd try running with jackplate all the way down and see if it happens. 

[SCFD rtrd.]

On ‎2‎/‎20‎/‎2018 at 10:08 AM, JEM said:

Does it alarm when you run at high speeds with the jack plate all the way down?  Generally, the jack plate does not need to be "up" much, if at all, during normal running.

Exactly, I can't think of any reason to run the jack-plate that high unless you are just trying to get on plane in shallow water. I would assume that running the jack-plate on 1 or 2 would provide the best performance and still get plenty of water.

[MCPathfinderUF]

Hey guys, ok I ran the boat again this time kept jack plate all the way down.  Ran from Eau Gallie causeway down towards Sebastian and back and no issues at all. That must have been what it was.   Thanks for the help. 

[Mike45q]

Similar Story with my new 200 VMAX SHO. Ran the jack plate up to 3 1/2 trying to optimize propeller, motor speed and RPM and didn't pay attention to my water pressure gauge,  and I got the alarm. Get a water pressure gauge and use it.  You really need it to optimize the Propeller Performance. OFX 4 Blade Props like to run high but motors needs water.

[mulligan]

Do the SHOs need that much more water to keep cool?

I have a Vmax HPDI and can run with the plate all the way up while still holding pressure, granted if I trim to the moon with it up I may drop to 10psi. I would think you should be able to run with it at 3-4" without any problem.  As stated above some props like to be ran higher.  If you have to run with the plate all the way down what is the purpose of it besides idling the flats?  I am not trying to be picky, just wondering.  

[mulligan]

Just thinking, scary I know, but do you have anything causing turbulent or aerated water close to the centerline of the hull like a transducer?  

[MCPathfinderUF]

I have on my 20 hour service visit list to get the water pressure sensor added.  I agree with mulligan I guess I wrongly assumed that the jack plate could be raised during normal operation to cross shallow areas on plane which I do fairly frequently in my area.

[JEM]

I know on my 2007V, with the 225 SHO, it will alarm if I run with the JP up near or to the top.  I was amazed the first time it happened, wondering why with the low water pickup!  My best performance, speed wise,  is usually with the JP all the way down.  I use the JP mainly to idle around shallow flats or bars or to get into or out of small creeks with shallow mouths. 

[SCFD rtrd.]

7 hours ago, mulligan said:

Do the SHOs need that much more water to keep cool?

I have a Vmax HPDI and can run with the plate all the way up while still holding pressure, granted if I trim to the moon with it up I may drop to 10psi. I would think you should be able to run with it at 3-4" without any problem.  As stated above some props like to be ran higher.  If you have to run with the plate all the way down what is the purpose of it besides idling the flats?  I am not trying to be picky, just wondering.  

Good point, but these factory rigged boats are probable not considered performance boats. The best example would be to look at the performance ratings of that hull on the Pathfinder web-site. The rating should show prop, and jack-plate height at maximum RPM and speed.