[fubarhubar]

I have a 2008 FX HO that I just bought with 10 hours on it. The craft runs great at 6000 rpm but overheats and shuts down at 8000rpm. it was in salt water before I bought it. It flashes code 01 when you hold the buttons for 10 seconds. I pulled the thermostat out and it overheats sooner. Any ideas where to start or what path to trouble shoot this?

 

[Ernest T]

Are you getting water out of the port side cooling water vent (you may have to run it for a few minutes above idle to see it)?

If you are getting water out of the port vent, I'd suspect a bad temp sensor. But if this sensor is bad you should be getting a code (15).

If you are not getting water out of the port vent, I'd suspect a blockage in the cooling lines someplace. Have you checked the pump for something you may have sucked up?

 

[fubarhubar]

I am going to do some testing today. will the side port open when run on a hose or does it need to be in the water?

 

[Ernest T]

I think the port side vent should work on the hose, but you may have to rev it a time or two. Water does not flow out of it all the time, but if you see a stream from it, it would at least help to tell that you didn't have a blockage in part of the system. You have to be over 5-6000 rpm for the starboard side vent to open.

I've heard that you can also feel the engine around each cylinder to tell if one of them is heating up right after you crank it from a blocked passage, but I don't know that I'd recommend trying to do that, since you could end up getting burned.

 

[bsjonsml]

I have a 08 FX HO that is overheating as well. I'm at a loss as to what could be the problem. I've flushed the unit forward and backwards. I've removed varies hoses to insure good flow. I've tested the thermostat and removed the exhaust water box to check for obstructions. I've removed the intake grate to make sure it is clean. I've run the unit on the hose for 10 to 15 minutes without any alarms. Everything seem to be working and flowing properly, but when it goes back in the water, I get a high temp alarm. I even removed the thermostat and ran it in the water and got a high exhaust temp alarm after only 5 minutes. Most tech in the area are at a loss as well. They tell me that they have had very few if any FX HO's overheating. I was thinking a sensor until the exhaust over temp came on. Now I''m not sure where to look. I don't think it could be both sensors at once. Any ideas?

 

[fubarhubar]

Weird fix

Hooked the craft up to Yamaha's diagnostic software and all it showed was one overheat at 12 hours. before hooking it up it would not start for some strange reason. we put new spark plugs in and it fired right up. after not finding any trouble codes on the diagnostic and not seeing the temps rise we took it back to the water and ran it with no overheating issues. There may have been a spark plug issue all along as it needed to crank over for a few seconds to start before the new plugs and with the new plugs it starts right up. Not sure if plugs were the problem but it runs great now and does not overheat.

 

[Ernest T]

Bad spark plugs are definitely "THE" biggest cause for problems on the FX models, but yours is the first I've heard associated with a high temp alarm. WEIRD!! :dunno: