1967 9.8hp prob

[Crushing]

Hay all Iam new to this form I have a 1967 merc 100 9.8hp will start for about one second with choke on I'd I open choke there is fuel in carb. It will at this point start with choke off. Also it will idel for a min or so then die missing every few seconds. Thw water is harly comming out pee hole at idel and is hot if i increase the throttle so will the stream. It has a new water pump I cleaned carb twice new gasket kit new plugs blue spark on both cylinders new fuel I can feel compressiod on both cylinders when pulling engine over reeds looked clean

 

[Dave_Seager]

I would not worry about the cooling system yet as it is not running long enough to get hot.

Running briefly and then stopping as you describe can be caused by a faulty fuel pump. I assume that you squeeze the bulb in the fuel line before starting. Have you tried squeezing it again once the engine is running? If this keeps it going then the main fuel pump may be faulty. I am not particularly familiar with Mercury outboards but many outboards of that period had a pump mounted on the crankcase. The fluctuating pressure in the crankcase worked a diaphragm in the fuel pump. The pumps are very small and contain two, tiny valves. If one of these fails to close then the pump will not work.

 

[Crushing]

Yes I pumped the blab befor and after starting with out change also took pump apart no tears. it will stay running if I increase the throttle but miss fire syne once every 5 sec

 

[Crushing]

Yes I tryed pumping bulb while running has not changed how it runs

 

[VicS]

Hay all Iam new to this form I have a 1967 merc 100 9.8hp will start for about one second with choke on I'd I open choke there is fuel in carb. It will at this point start with choke off. Also it will idel for a min or so then die missing every few seconds. Thw water is harly comming out pee hole at idel and is hot if i increase the throttle so will the stream. It has a new water pump I cleaned carb twice new gasket kit new plugs blue spark on both cylinders new fuel I can feel compressiod on both cylinders when pulling engine over reeds looked clean

What do you mean by "I open choke there is fuel in carb. It will at this point start with choke off."

If you mean there is fuel visible in the choke tube / air intake then it sounds as though the carb may be flooding.
If so the float may be defective or sticking or the needle valve may not be closing properly due to a worn seat or simply dirt in the valve.

Diagram of carb HERE

 

[Crushing]

carb

when i choke the outboard and try to turn over the engine I see a little puddle of fuel in carb at idel tube. then I turn choke off and it stats in two pulls seems to missfire i rebuilt carb a day ago new needle valve and seat gasket sets and cleaned carb soaked in carb cleaner over night