1982 Mercury 150 will not start.

Capricorn-76

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Any help would be greatly appreciated. I have a 1982 Mercury 150 hp motor that will not crank. It will turn over, just won't start. I have changed all 6 ignition coils, spark plugs, and wires. I have checked the spark with a spark tester and all 6 are producing a strong spark. I have also tested the compression of each cylinder, and they are all within the 118-120 psi range. I have fresh gas with oil, and double checked to make sure no water was in the gas. I also have a new battery. I have done all that I know to do. I have checked the kill switch on the throttle control several times, and it is up in the run position. I have even tapped on the mercury switch on the motor several times. When I prime he motor, I squeeze the bulb until hard, and then give it several extra squeezes. However, when I try to crank it, all it will do is turn over. It doesn't spit or sputter, or even act like it's going to start. All it does is turn over. Any information and suggestions would be greatly appreciated. Thank you in advance for your time.
 

Dukedog

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I have checked the spark with a spark tester and all 6 are producing a strong spark.

this pretty much its not gettin' any fuel....also tells its not anything with kill or mercury circuit...... are ya usin' tha tha "push ta choke" function?.... tried squirtin' a little pre-mix in tha carb throats???
 
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Capricorn-76

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Yes sir, I have been using the push choke. I haven't sprayed any pre-mix, but I have sprayed a very small amount of starting fluid into the carbs. Also, I can see the fuel going through the fuel line to the carbs as it's turning over.
 
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fhhuber

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Squirt about an ounce of fuel mix down each carb barrel. (I'd squirt 25:1 mix in... a bit of extra lube won't hurt)

The engine should run a few seconds.

If it passes that test you have a fuel pump and/or carb issue. If not you might need new reed valves.

Its a quick cheap test...

Just to feel good... put about 1/4 oz fuel mix in each cyl through the spark plug hole. You have spark and compression it should pop right over a few times if timing is set right.

**************

Do not squirt starting fluid into a 2-stroke outboard. Its a good way to blow it up. It can ignite in the crankcase. It has no lube so you are trying to run the engine with no oil.
 
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Capricorn-76

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Mr. Dukedog and fhhuber, Thank you both for your help. I tried what y'all said about squirting some fuel mix into the carbs and cylinders. After three tries to turn it over, it fired up. I was expecting it to run for only a few seconds, but it continued to run. I let it sit and idle for several minutes and then turned it off. It started right back up. I let it idle for a several more minutes and then shut it off. I let it sit for about an hour, them tried cranking it again and it wouldn't fire, but I squirted a little bit of fuel mixture into the carbs again and it fired right up. I'm not sure what would cause that, but I am thankful for y'all's help. Y'all got my motor running again.


What octane fuel do you recommend for a 150 hp?
 

Dukedog

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enrichner not workin' probably.... can you hear a "click" when tha key is pushed?... may need ta swing tha cowl open ta hear it.....

think its got tha enrichner?.. don't remember for sure when it showed up... if not, it will have regular solenoid operated "choke plates" built in ta tha air box
 
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Dukedog

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first need ta know if your "holding" tha key in while crankin' or ya just doin' tha push and release?.. if push and release forget that and hold it in while crankin'....

find tha enrichner valve/solenoid (part makin' tha click) there should be two 1/8" id hoses attached to it... one goes to tha "bottom" of tha top carb.. tha other goes to tha "top" of tha middle carb... take tha one goin' to tha middle carb loose at tha carb or tha valve.... punch tha key in and hold.... if tha thing clicks you should get fuel from tha disconnected hose.... if none then take tha other loose from tha valve.. should have drainage from tha top carb.... if not pump tha bulb... should get it then.
 
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