Snobo4rder08

i was out on Lake Michigan last weekend and noticed when after running 40mph for about 45min my water temps creeped up to 195ish, then continued after another 15min to 210ish. The boat never beeped at me at those temperatures and it does beep at me when I have low oil or low drive lube.

took boat off water and replaced the impeller which was in perfect condition but since I had it apart I decided to do it anyways. So thinking that wasn't the problem I flushed entire water lines with the hose and also replaced the heat exchanger gaskets and washers.

took boat out on lake by my house and temps were in the 175-185 range after about 10min of riding mid throttle. I went and tapped on the gauge and the needle moved back and forth in a 15-20 degree range. Not sure if that's normal for the needle to move when you tap on gauge.

side note not sure if this mattters at all but I am curious to why my port side headers always run hotter then my starboard side. They are cmi headers

does anyone have any idea what's going on?

496ho in a outlaw 25
270 hours
all fresh fluid this year

dereknkathy

The first place to look is the fitting where the water comes through the transom. It is a choke point to begin with, so it can get plugged up.

Plum_Crazy

I once had a 496HO that was overheating and it turned out to be debris stuck in the oil cooler on the backside of the engine. I had back flushed as well, but it didn't blow this stuff out.

Snobo4rder08

Where does the water come through the transom general location so I'm not standing on my head for 10min looking for it?

also for the oil cooler was it stuck in the oil cooler feed line or actually in the cooler itself?

thsbk you

mike tkach

iTrader: (3)

if your gauge moves 15 to 20 deg just from tapping on it you need to replace it.also when the raw water pump goes bad the small rubber peices get caught in the cooling tubes in the water side of the oil cooler and reverse flushing get some of it but usually not all of it.i have used a coat hanger and pushed the junk out many times.a 502 mag should run at 170 to 175 deg,no hotter.

Snobo4rder08

When I inspected impeller it was still in new condition not missing any fins.

Snobo4rder08

I am very interested in if anyone knows why my port side header gets super hot and my starboard is cool to the touch. Water does come out of both of tHem.

they are the cmi headers

F-2 Speedy

iTrader: (6)

this could be blockage also

Snobo4rder08

I felt all my header primaries the only one that is scolding hot is the port side the one closest to the front of the engine every other is cold

mike tkach

iTrader: (3)

is this with the boat in the water or on the trailer using the garden hose?