9.5 problem

[jim kinser]

I have a '67 9.5hp johnsn that runs ok for a minute but won't idle. It acts like its starving for fuel. I cleaned carb, replaced fuel line from pump to carb, it pump fuel ok, it's got 65 lbs compression. Any suggestions ?

 

[tashasdaddy]

Re: 9.5 problem

read this, http://forums.iboats.com/showthread.php?t=167352 your compression sounds low to me. try decarbing if you can get it running.

Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

afterwards compression.recheck

 

[mchin]

Re: 9.5 problem

I would follow Tashasdaddy advice as it will help, but I have a couple of 9.5's with about 65 lbs of compression, they all run great, albeit a bit slow for a 9.5. They are outputting about less then or equal to my 58' 7.5 hp johnson.

is it dying in a barrel or on the water? with hood on or off?

is the bulb staying firm or flattening out.?

when you did your carb, did you replace your float and "O" ring/washers on the low speed needle?

If you hadn't I would suggest buying a carb kit and doing the whole magilla again.

good luck and keep us posted on what your solution turns out to be.