150hp mercury starting proplem

vic5758

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Sep 30, 2009
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I took boat out last week and it was running fine a few days later i tried to start motor and it just dosn't start..please help


this is what i have done to motor (twin 150hp 2001 salwater series)

new battery
cleaned carbs
checked starter works fine
new plugs
 

vic5758

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Re: 150hp mercury starting proplem

I came back from fishing took boat to my moorings shut motors (twin) off cleaned boat and fired motors one more time peace of mind i Guess one started the other no thought it was flooded came back a few days later and still doesn't start.....

HAS BLUE SPARK AND COILS O.K
 

Dukedog

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Re: 150hp mercury starting proplem

Probably fuel related then......Does it even attempt to start?
 

vic5758

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Re: 150hp mercury starting problem

Re: 150hp mercury starting problem

no it doesn't attempt to start, i even sprayed that engine starter in the carburetors and nothing...


I SHOULD ALSO MENTION THAT WHEN I WAS COMING IN THAT DAY (CRUISING) THE MOTORS HIT BOTTOM (SAND) I DON'T KNOW IF THATS A FLUKE THAT THE MOTOR IS NOT STARTING OR IT'S RELATED...
 

Dukedog

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Re: 150hp mercury starting proplem

First and foremost. Don't spray ETHER in a two stroke unless you really know what your doing which you may. I donno. It can dry out a bearing/rings instantly. If you put anything in the motor it should only be a pre-mix. Really hard to say what it is now. Get a squirt can of pre-mix, trim the motor all the way down, open the butterflies, squirt fuel in each venturi, close the butterflies, hit the start and see what happens. If you have fire and you have fuel in the clyinders it should at least "fart" if it doesn't try to run. If it doesn't do either then without being there someone else needs to jump in here to help............D
 

vic5758

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Re: 150hp mercury starting proplem

D, do you think i could have knocked the timing out when the motors hit ....
 

Dukedog

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Re: 150hp mercury starting proplem

No. Not without causing a lot of damage that would be very visible. Even with tha timing waaaaay off it should do something when you put fuel/oil mixture in the clyinders and the plugs have fire. Did you try what was suggested above? Have you done a compression check? Did the motor overheat? Do you have a manual (Merc, not Seloc)? Without being able to see and hear what the motor is doing it may be over my head trying to do this on a computer. There are a LOT of varibles.....D
 

j_martin

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Re: 150hp mercury starting proplem

Check the Kill circuit. (kill switch, ignition switch or relay, tilt switch on the engine)

You could disconnect the kill wires from the switchboxes, replacing them with jumpers so you can short out both terminals to ground without getting shocked. Then try to start it. Short the test jumper to ground or choke it to kill it.

If it starts, follow the kill circuits back with an ohmmeter, looking for a short to ground.

If you have no idea what I'm talking about, it's time to acquire a maintenance manual.

hope it helps
John
 

Dukedog

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Re: 150hp mercury starting proplem

John, he said earlier that the plugs had fire and sprayed ether (startin' fluid) in the carbs. Thats what makes it strange. Fire and fuel will do SOMETHING! Might not sound so good but will at least make some kinda noise............
 

vic5758

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Re: 150hp mercury starting proplem

d, took your advice and used gas/oil in a spray bottle, removed spark plugs and spayed some inside and in the carbs and not a fart,cough or hiccup and i do have a mercury service manual previous owner gave it to me when i purchased the boat 3 months ago in Florida boat here in Bermuda now where i reside...........checked compression 125 on two and 120 on the other four...
 

Dukedog

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Re: 150hp mercury starting proplem

If you have done all that and you know that the plugs, not just the coils or wires, are firing (even if the timing is off) and still not even a whisper its over my head doing this on the computer. Being there might be different. Sorry man. Hope you find it. Maybe someone else on here might have an idea. Maybe something simple we are over looking...........D

One other thing you might check. Make sure the trigger arm is still attached to the timing advance arm.
 

j_martin

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Re: 150hp mercury starting proplem

John, he said earlier that the plugs had fire and sprayed ether (startin' fluid) in the carbs. Thats what makes it strange. Fire and fuel will do SOMETHING! Might not sound so good but will at least make some kinda noise............

I suspect that he's pulling a plug and noting that it fires in open air. It takes about 5 times the snap to fire it under compression.

If it has compression and gas, and doesn't fire, then it doesn't have (enough) spark.

A leakage to ground in the kill circuit will manifest symptoms like that. So will a dead short in the rectifier, mag loading the stator and depressing the charge coil output.

The flywheel is splined, so you won't have the slipped timing problem you can have with a keyed flywheel.

I'm giving him the easy quick check. After that it's DVA and charts.

hope it helps
John
 

vic5758

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Re: 150hp mercury starting proplem

thanks dukedog for your time i really appreciate it i will keep on trying at least for another week before i eventually take it to a merc mechanic........
 

vic5758

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Re: 150hp mercury starting proplem

J martin i have been testing the spark holding the plug against the head and i see a blue spark i repeated the process with all the coils,can a spark plug tester tell me if the spark is weak if so then i will pick one up tomorrow....

i just can't see it being a big problem because i came back to my moorings and didn't notice or hear anything out of the ordinary shut motors off cleaned boat restarted (motors peace of mind) and only one fired up and has been like that since any help would be greatly appreciated............
 

Dukedog

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Re: 150hp mercury starting proplem

Here's a little trick we used many years ago when we didn't have the funds for good tools. Take the three plugs out on each side. Plug them back into the plug wires. Now take a ty-rap and/or zip-tie, whatever you wanna call it and bundle all three plugs together making sure the outside metal on the plugs are touching. Get a jumper wire with alligator clips on each end. Clip one end on the threads of one of the plugs, the other end to a good motor ground. Turn the motor over. This lets you see what the spark looks like, if they are all firing, or if any fire is there at all...................
 

CharlieB

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Re: 150hp mercury starting proplem

Spark must be enough to jump a 7/16 inch gap, any less and the motor may not start.

A shorted ignition switch MAY still give you a SHORT spark, but if it does not pass the gap test, then pull the black wire with the yellow trace from between the ignition modules and the wiring harness and repeat the spark test.

If it NOW passes, then reconnect the wire and disconnect it from the ignition switch end and retest again.
 

vic5758

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Re: 150hp mercury starting proplem

i have twin mercs and i to thought i might have a bad key ignition switch so i disconnected harness from moter that works and plugged it to the other one and still same result .................
 

j_martin

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Re: 150hp mercury starting proplem

J martin i have been testing the spark holding the plug against the head and i see a blue spark i repeated the process with all the coils,can a spark plug tester tell me if the spark is weak if so then i will pick one up tomorrow....

i just can't see it being a big problem because i came back to my moorings and didn't notice or hear anything out of the ordinary shut motors off cleaned boat restarted (motors peace of mind) and only one fired up and has been like that since any help would be greatly appreciated............

That's what I said you were doing. It needs to jump a way bigger gap in free air to jump the spark plug gap under compression.

Go get a spark tester, set it at 7/16" on all 6, and see what ya got.

Yer also stuck on the bump being significant. It might not be.

hope it helps
John
 

Karl_Childers

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Mar 2, 2009
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Re: 150hp mercury starting proplem

This is kind of a far fetched theory, but you might have twisted your crankshaft when you tagged the bottom. Like I said, it's unlikely, but worth investigating.

If you have fire and fuel and no "farts" then you need to look at compression and timing, it's the only things left.

Please post back and let us know what you find.

Rob
 
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