78 merc 110 9.9 hp cooling problem

Hi <br />I have a the above mentioned engine and have replaced the impeller. I just bought this motor and it was not pumping so I replaced the impeller. after lake test it only stream out the tell tale every once in a while and actually seemed to quit streaming at all. when I run it in gear at rpm there is steam coming from exhaust ports It did seem to shutoff once and I believe it was the heat sensor shutting it down if there is one on this motor. Any ideas about what I should look for..I also have a 95 9.9 2stroke merc that used to pee really well and now it has a diminished stream. It seems to be coolikng ok just not flowing well. I inspected the impeller on this motor and it looks great..<br />sowhat do you guys think maybe a block restriction on both on thermostat problems maybe?<br />thanks for your help?

Re: 78 merc 110 9.9 hp cooling problem

Must not be a popular subject....

Re: 78 merc 110 9.9 hp cooling problem

The 9.8 engines had a couple of problems after a impeller went to peices, if the got real hot they melted a plastic retainer on the water tube right under the powerhead and if the impeller peices were not cleaned out the new pump would pump them in to the engine, the first place to look for them is under the exhaust plates if the are not there they will be in the water passage from the exhaust cooling area to the block to find them there you will have to remove the water jacket cover (head plate) from the block to get them out NICE HUH? In as much as if you don't find them one place, you just go to the next I usually just figure on doing it at and being done with it--Bob

Re: 78 merc 110 9.9 hp cooling problem

This can also be caused by the exhaust gasket failing and allowing exhaust into the cooling system.

Re: 78 merc 110 9.9 hp cooling problem

unbumping this thread... I posted a new one about my 9.8...