Itsallgood995

I switched from OMC to Bravo over the winter & now seem to have an overheating issue. With the OMC, the motor would rarely see 135 degrees. After the first run this season with the bravo it ran about that for most of the day but then progressively got hotter & hotter…pegging the needle @ 240. You can put your hand on the exhaust & it feels cool. The motor is hotter but I wouldn’t say its anywhere near 240. I thought it was the thermostat so I drilled some holes in it. No difference. I then replaced the thermostat & then the sender too. The motor now will run @ 160 but will climb up to 200 when tubing or running hard. If I let it idle the temp will come back down to 160 & stay. Last night I checked the impellor, its flexible & fine. I also back flushed the oil cooler & power steering cooler & I didn’t notice any sediment. I haven’t run the motor yet but don’t feel like I’ve solved this? Should I drill 4ea holes in the new thermostat? I’m not running a cross over. Any suggestion?

boomer

You sure you have the correct hose on the intake of the sea water pump?

Itsallgood995

The intake hose is not factory merc hose but is a high quality fiber wrapped suction hose so it shouldn’t be collapsing.

Itsallgood995

Partially plugged intake ports or low water pick-ups? Is it ok the blow compressed air into them?

boomer

Now worried about the hose collasaping just want to make sure the intake side is the intake so its not backwards,

Itsallgood995

The intake is on top of the sea water pump. Wouldn't it not pump any water if it was reversed? Yesterday the temp would climb to 240 @ idle & then drop back to 160 when running hard. Completely opposite of what it was doing the other day?

I'm now thinking it may be a ground issue. The horn, blower & beilge pump don't work. These things do work when I bypass the wire harness. The fuses are fine & there is power to the switches. I'll look for lose ground wires unless I'm off base on this thought?

MILD THUNDER

iTrader: (3)

Check to make sure the temp gauge is grounded to a good ground. A weak or loss of ground to the gauge can cause high temp readings.

Itsallgood995

Looks like most of this is a weak ground issue but the temp does climb still @ idle. The guage will peg @ 240 but the thermometer gun says its closer to 190. The temp will drop back to 160 once under way.

I'm now second guessing the intake hose thinking it may be too big? Its a clear 1.1/8" fiber reinforced hose. Is the factory hose 1" with flaired ends? If you hold the hose @ idle there doesn't seem to be a lot of volume going through it.

apollard

The bravo pulls through a 1 1/4 inch hose that goes to the transom, then pulls through about a 3/4 ID hose to the drive. It creates alot of suction pressure in that system. Not sure where you got that hose, or what type it is, but it sounds like hose you can get at the hardware store that is really meant for pressure, not suction. I'd think it isn't able to handle the suction, but maybe I'm not understanding the hose you have. Mine has a hardwall hose with wire reinforcement. You can't collapse it with your hand. Even with large pliers would be tough.

The othe possibility is a curse of bravos - corrosion collapses the ends of the hose between the drive & transom, resulting in low flow. I've heard it called Bravo fever.

Mr. Cool

I know you checked the impeller, but did you confirm oil and water flow?


Russ