Yam 150 / Grady 180 - Engine temperature

[corinthmistral]

Probably should post on the Yamaha forum too - took the boat on a run today - 2008 Grady White 180 with a 2008 Yamaha F150 with 250hrs. At higher revs (above 4K) the temperature crept up to around 2/3 on the gauge. I haven’t honestly noticed before but thought it always used to sit in the middle of the gauge regardless of revs. Is this normal and will it do any harm? I had the engine serviced 20 hours ago which (supposedly) including a thermostat - I have an invoice listing it. As ever, thanks in advance.

 

[DennisG01]

The easiest answer is a worn impeller or grooves in the impeller housing/wear plate. I would inspect that. If you're paying someone to do this, just have it done. After that, the fix can get momre costly... cooling passage clogs, etc.

 

[corinthmistral]

The easiest answer is a worn impeller or grooves in the impeller housing/wear plate. I would inspect that. If you're paying someone to do this, just have it done. After that, the fix can get momre costly... cooling passage clogs, etc.

Thank you. Good advice. I will check that.

 

[wspitler]

My F250s did exactly that for 1000 hours. The gauge is not linear and if you are concerned, either buy the YDIS software and cable (about $50) and read actual temps, or hook up to a MFD via NMEA2K and read actual temps, or use a laser thermometer on the housing. I believe you'll find the temps are around 140-165F and that is just fine. The thermostat specs full open at 158F. Never hurts to check cooling system components if not done recently, but the temp alarm and overheat warning is a nominal 266F. Gauge will be pegged..

 

[corinthmistral]

My F250s did exactly that for 1000 hours. The gauge is not linear and if you are concerned, either buy the YDIS software and cable (about $50) and read actual temps, or hook up to a MFD via NMEA2K and read actual temps, or use a laser thermometer on the housing. I believe you'll find the temps are around 140-165F and that is just fine. The thermostat specs full open at 158F. Never hurts to check cooling system components if not done recently, but the temp alarm and overheat warning is a nominal 266F. Gauge will be pegged..

Looks like someone raised the exact same query last year - looking at their photo of the gauge, their engine (also a F150) was running at the exact same temp at similar revs so I’m less concerned now.

https://www.thehulltruth.com/boating-forum/1176533-yamaha-f150-running-temps.html

 

[DennisG01]

I guess it depends on what you said in the first post. If it's DIFFERENT than where it normally shows at, then that's an indicator that there's a problem. When I read your post, that was the feeling I got. However, if it stays in the same area, time after time, then I would't worry (or reacts the same time after time). It's more about "trends" than an actual number.