90 Mercruiser Overheats - bogs under load

[Starcraft5834]

lower unit O-ring crack contribute to over heating.. no.. don't think so... sounds like impeller not doing its job

 

[bairdo3]

Been working on boat. I dropped the lower unit and checked everything out. Everything looked new. Put everything back together and rather than using muffs, put outdrive in a bin of water. Pulled water inlet hose to check water flow and NO water was being sucked in..however would with muffs. I took apart agian to make sure everything went together correctly and reinstalled, even backflushed to make sure there was no clogs. Still NO water being sucked in. I have no ideaa what it could be. Need HELP before I sink this boat.

 

[henleyhale]

lower unit O-ring crack contribute to over heating.. no.. don't think so... sounds like impeller not doing its job

I second this reccomendation, your willing to put a new carb on it, but over look the raw water pump, why?
As an impellar sits the rubber in it forms and shrinks. It can be brand apankin new 5 years ago and never run then require replacement before getting on the water, just cuz it looks good and new doesnt mean a thing.

 

[bairdo3]

I understand that. However it was replaced less than a year ago with only 15 hours on it. And it still bogged under load same week I out it on. Checked to make sure it was working properly also.

 

[Scott Danforth]

Been working on boat. I dropped the lower unit and checked everything out. Everything looked new. Put everything back together and rather than using muffs, put outdrive in a bin of water. Pulled water inlet hose to check water flow and NO water was being sucked in..however would with muffs. I took apart agian to make sure everything went together correctly and reinstalled, even backflushed to make sure there was no clogs. Still NO water being sucked in. I have no ideaa what it could be. Need HELP before I sink this boat.

an I/O will never suck water from a bucket (unless the bucket is big enough to put the whole boat in it) because the pump needs to be primed first.