1993 mercury force 90 hp not starting

[Bottomfeeder33]

I have a 1993 mercury force I recently replaced a blown head gasket as I was going to do a full rebuild but pistons and rings seemed to be fine I have 140 psi on all three cylinders and I have changed fuel lines and cleaned carbs and put new spark plugs in. When I get it to start with starting fluid it will backfire a few times and then die off. Does anyone know what else I should check ?

 

[racerone]

Check plug wires.----Check flywheel key.

 

[Drivewayboater2]

in addition to racerone‘s response.....Could be the reed block, fuel pump, timing issue... could be a carb issue...lots of things
read Frank A’s stuff in the stickies.... he was the man on Force engines

 

[racerone]

How did it run for you last season.----What happened ?

 

[puffitu]

Carb floats? Fuel pump diaphragm?

 

[Redbarron%%]

Pull the carbs and clean them and blow out the passages with compressed air.
Make certain you have fuel flow to the carbs and the bulb pumps up hard.
Also make sure you have fresh fuel.
If it starts on starting fluid then it should run on gasoline.
I make a habit of making sure that there is spark current by using an induction timing light on all cylinders.
If fuel stayed in the carbs and gummed up the most likely thing is clogged idle circuit etc.

 

[The Force power]

I have a 1993 mercury force I recently replaced a blown head gasket as I was going to do a full rebuild but pistons and rings seemed to be fine I have 140 psi on all three cylinders and I have changed fuel lines and cleaned carbs and put new spark plugs in. When I get it to start with starting fluid it will backfire a few times and then die off. Does anyone know what else I should check ?

In addition to all the great advice pervious mentioned
Do yourself a favor; stop using starter fluid as this dissolves the needed lubrication for the pistons, get a fuel rated spray bottle and premix fuel.

 

[jerryjerry05]

One backfire even a tiny one can blow the port cover gaskets and then the backfire can get worse and then it runs crappy until the gasket or gaskets are replaced.
Where are the idle/air screws on the carbs set?? Should be about 1 1/8th turn out from lightly seated. Some won't operate at that setting, you just need to experiment with the settings All 3 should be close to each other.
The fuel pump's run off the #2 cylinder and if the diaphragm is bad it can flood the motor causing the backfire.
You mess with the timing? They don't jump time like a car and if someone's adjusted it???

 

[Bottomfeeder33]

One backfire even a tiny one can blow the port cover gaskets and then the backfire can get worse and then it runs crappy until the gasket or gaskets are replaced.
Where are the idle/air screws on the carbs set?? Should be about 1 1/8th turn out from lightly seated. Some won't operate at that setting, you just need to experiment with the settings All 3 should be close to each other.
The fuel pump's run off the #2 cylinder and if the diaphragm is bad it can flood the motor causing the backfire.
You mess with the timing? They don't jump time like a car and if someone's adjusted it???

Bad diaphragm and adjusted the idle screws to what you said and motor fired right up. Haven’t had time yet to take it to try it out. Thanks for the help