Grrrrr Motor won't start !!! 1986 Merc 175hp

[NESAR]

Here it is I just got my motor back from the shop. Wasn't firing on 2,4,6 cyl. The guy at the shop told me it runs good so I got it home hooked up the ears,tried to start it and nothing! It turned over fast I now have spark in all 6 Cyl, plugs are wet so I think its getting fuel. What can I be doing wrong. He also told me I was running 120 for compression.
Now when I as at the shop I asked him to hear it run so he hooked up the battery didn't put no water to it because he wasn't going to keep it running. It fired for a quick second he shut it down but, when he tried to start it it backfired a few times. I asked him why he told me fuel. So after a few ties it fired up with a backfire and he shut it off. I took it home and did all the above.

I'm getting spark that I know for sure. Fuel I think because the plugs are wet. What more can it be but air. also he told me the that he adjusted the carbs. I know they was just done 4 months before he got the motor but , he said they was off.

It is a 1886 merc 175hp I was also wondering if there is timing on these motors? If there is how do you check it?
Also jut to let yo know what he did he changed the switch box and a solenoid to the starter.

 

[jigmister]

Re: Grrrrr Motor won't start !!! 1986 Merc 175hp

you need a new mechanic. The engine should never be started for even a few seconds dry. The impeller is surley damaged now.

 

[CharlieB]

Re: Grrrrr Motor won't start !!! 1986 Merc 175hp

you need a new mechanic. The engine should never be started for even a few seconds dry. The impeller is surley damaged now.

That's for sure!

ALWAYS turtn on the water if the motor may start, it only takes a SECOND for the impeller to heat up at running speed.

You can check timing with an inductive timing light connected to #1 spark plug wire without starting the motor. Remove all the spark plugs, plug the wires back onto the plugs tape the plugs together. As you are taping the plugs together add a length of wire so you can ground all the plugs to the motor block.

Crank the motor and see where the timing mark is, it should show shortly after top dead center with the throttle at idle position. @ to 8 degrees, depending on the motor.

If the timing seems way off, disconnect the throttle cable, open the throttle arm to wide open and see where max timing is, it should be right around 22 degrees.

If max timing is very far off you may have to remove the flywheel and check to see if there is a key that has sheared off, allowing the flywheel to shift position on the crank.

 

[NESAR]

Re: Grrrrr Motor won't start !!! 1986 Merc 175hp

Thank You for the info i'll check that.

 

[NESAR]

Re: Grrrrr Motor won't start !!! 1986 Merc 175hp

I have one more question. Does the fuel line have to be under pressure at all times or can I just use what is in the filter to see if it fires up? I didn't have the fuel line under pressure.

 

[jigmister]

Re: Grrrrr Motor won't start !!! 1986 Merc 175hp

as long as there is fuel in the carb bowls it should fire up and run for a bit.


what do you mean by not under pressure? the fuel pump dose not apply pressure until its running any way

 

[NESAR]

Re: Grrrrr Motor won't start !!! 1986 Merc 175hp

as long as there is fuel in the carb bowls it should fire up and run for a bit.


what do you mean by not under pressure? the fuel pump dose not apply pressure until its running any way

I checked the carb bowls there was fuel in all 3. I was asking if the primer bulb needed to be under pressure.