no spark on '76 Mercury 175 v6 2 stroke

[fattKyle]

I am trying to get the old engine to run after being stored for 5 years. It is a 1976 Mercury '1750' (175hp) v6 2 stroke w/ thunderbolt ignition. i have already cleaned and replaced gaskets in all 3 carbs, new fuel and hoses, new battery, new impeller, ect...

My problem: no spark from the plugs. all i did was pull out a plug and touch it to the closest bolt with out paint. i just want to know some common problems with these old mercs.

 

[Faztbullet]

Re: no spark on '76 Mercury 175 v6 2 stroke

Go to CDI electronics website and download the troubleshooting manual 1st and get a servive manual 2nd. These older models are known for bad insulation on stator an trigger and if falling off /cracked replace them, dont try to repair them as it causes problems. You lack of spark could be a stator,trigger,mercury tilt switch,kill switch unplugged(up by control)keyswitch..

 

[fattKyle]

Re: no spark on '76 Mercury 175 v6 2 stroke

Turns out it wasn't spark, it actually started. But now the fuel line wont get pressure when the boat is level. I have to raise the front of the boat as high as the trailer will go so the line will get gravity fed. Even though it has a full (18 gal) tank. Then I will get fuel to the primer bulb and it will start.

What could be the problem?

 

[Ruddell]

Re: no spark on '76 Mercury 175 v6 2 stroke

Sounds like a low pressure fuel pump(the lift pump) I believe are used on those models.
1st, this may sound stupid, check your primer bulb to make sure it is going in the right direction.
2nd, you need to run a vacuum tester to make sure the lift pump is working.

These lift pumps work off of the positive and negative primary crankcase pulses to move the diaphragm. Could be the reference line(or the pump could be bolted directly to the crankcase to draw these pulses).

If fuel sat in the pump the diaphragm in the pump could be dry rotted.

Hope that helps good luck!