BF 225 Alarm

Ran boat this weekend and no issues at all until I put the hammer down over 5200 RPM's then the alarm sounded. Let it set for 30 seconds or so then went on not wanting to push the limit again, I kept the RPM under 4500 RPM. Never alarmed again. I just had replaced all the fuel filers, Low, High pressure and spin on. Anyone suggest that I need check the thermostats? Not sure if they have been replace from pervious owner. Motor is 2007 with 318 hrs.

Thanks,
Chad

That's not much info to go on.

Are you operating in saltwater?

Was the alarm continuous, long intermittent, or short intermittent?

Do you have the four light key switch - oil pressure, alternator, overheat, and MIL (check engine)? If so, what lights were on and off when the alarm sounded. If so, you can pull detailed fault codes which will help isolate the problem.

Post your engine serial number. 2007 is when they changed over to the new modified exhaust tubes.

If the alarm was long intermittent, that typically indicates a problem with the programmed fuel injection (PGM-FI). And given that it is a BF 225, the first suspect is the high pressure fuel filter. If you just changed that, did you remember to re-install the spring on the bottom of the filter? Are you sure that the flimsy little O ring is properly in place? There are several other filters and screens in the fuel system that you might want to check. I've posted those several times on this forum.

CHawk,

Yes motor is always in saltwater down here on the Texas coast.

I have the four light key switch and the red light all the way on left as on, which I believe is water temp? The beep was a long continuous beep. I had the high pressure filter replaced last year by a boat mechanic and only has about 15-20 hrs since. Also the lower unit was replaced only has about 10 hrs. I just replaced low pressure fuel filter and spin on before running. I had run the boat about 3 hours before the alarm when off, but again I put hammer down for about 1 min that's when I got the alarm. I'm going to go ahead and replaced thermostats since it's never been done and I got 311 hrs on motor.

That is the overheat light. OK on replacing the T-Stats.

Suggest that you test the old T-stats in a pot of hot water on the stove, using an instant thermometer. They should start to open at 140 F and be fully open at 160 F. Fully open is only 3 mm. If one is stuck closed, or doesn't open all the way, that is likely your problem. Also, clean out the seat area where the t-stats sit. Be sure to use new O rings.

If old t-stats are working OK, then you should drop the lower leg and change the water pump. Inspect the vanes on the old impeller closely to make sure none have broken off. If so, then you will need to flush the water passages with high pressure.

Changed T-Stats and noticed one was stuck open. A bunch of corrosion was in the seat area. Also blew the lines out with high pressure air. I don't have time to drop it in the water to test out, but I think this was the problem....