Mercury 7.5 Starting Problem

[TonyO]

I have a 1972 Mercury 7.5. When I pump the primer bulb gas flows out of the carburator and into the bottom of the engine compartment. The engine is on an engine stand and the carb is positioned level. From looking at the carburator the fuel jet appears to be aimed opposite the throat of the carburator.

On another note, locking the engine cowling seems to be a difficult, any tips?

 

[Plainsman]

Re: Mercury 7.5 Starting Problem

Welcome to iboats Tony!!
If you prime the bulb enough, the fuel has to go somewhere, so it will spill out the carb.
Do you have spark? Have you done a compression test?
You also may want to do a decarb once you get it started. The proceedure for that is in the FAQ on the top of this board.

 

[Bilge Monkey]

Re: Mercury 7.5 Starting Problem

You may be over overpowering the N@S in the carb if you are pumping hard, otherwise they may be worn.I would leave the fuel jets alone.

 

[Don S]

Re: Mercury 7.5 Starting Problem

If the gas is coming out of the carb without really pressurizing the bulb, then you may have a dirty needle & seat in the carb or a defective float.

You may have to remove the carb, clean and rebuild it.

As far as the cowl latch, have you tried lubing it and/or adjusting the latch?

 

[troy6242@gmail.com]

Re: Mercury 7.5 Starting Problem

I have a Mercury 5hp and can't seem to get it to start. It has good compression but does not appear to be getting a spark. Where should I start?