8hk motor won't start when warm

[imported_griz]

hello: been meaning to write this letter for 3 days but keep getting caught up reading other peoples postings. theres an amazing amount of info here.
i've got a 8hk crescent marin, penta(volvo) outboard. serial 809057, 2 cyl, water cooled, year 78-80. starts first or second pull runs great for 5-10 min. just enough time to get to where the big pike are. then refuses to start again for at least an hour some times longer. new plugs, points are good(0.20) impeller seems fine. fuel filter is clean. motor feels too warm to me after only 10 min. but i'm no expert. any ideas??
thanks in advance
griz

 

[ronshire]

Re: 8hk motor won't start when warm

sounds like the classic overheating problem. check that the inlet ports are open, check that water can flow thru the tubes from the water pump to the motor and out the discharge ports.

if all this is clear and ensure that you have a good impeller then it's highly likely that the water passages in the head are blocked. this would not be the case if water can flow thru the input tube and out the discharge ports.

pull the impeller and replace it. they often get old an brittle and some of the vanes break off. also it could be so old that the bldes have taken a set so they no longer touch the sides of the housing


i've got a 8hk crescent marin, penta(volvo) outboard. serial 809057, 2 cyl, water cooled, year 78-80. starts first or second pull runs great for 5-10 min. just enough time to get to where the big pike are. then refuses to start again for at least an hour some times longer. new plugs, points are good(0.20) impeller seems fine. fuel filter is clean. motor feels too warm to me after only 10 min.

 

[ronshire]

Re: 8hk motor won't start when warm

sounds like the classic overheating problem. check that the inlet ports are open, check that water can flow thru the tubes from the water pump to the motor and out the discharge ports.

if all this is clear and ensure that you have a good impeller then it's highly likely that the water passages in the head are blocked. this would not be the case if water can flow thru the input tube and out the discharge ports.

pull the impeller and replace it. they often get old an brittle and some of the vanes break off. also it could be so old that the bldes have taken a set so they no longer touch the sides of the housing


i've got a 8hk crescent marin, penta(volvo) outboard. serial 809057, 2 cyl, water cooled, year 78-80. starts first or second pull runs great for 5-10 min. just enough time to get to where the big pike are. then refuses to start again for at least an hour some times longer. new plugs, points are good(0.20) impeller seems fine. fuel filter is clean. motor feels too warm to me after only 10 min.

 

[steelespike]

Re: 8hk motor won't start when warm

VERY CAREFULLY Feel the head it should be too hot to keep your hand on but not so hot it burns you.
Also if the carb is flooding a little (from a float problem
or maybe a choke malfunction)It might start cold but refuse to start warm.Check for spark when it refuses to start.