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88 force 125 won’t run/ backfire?

O

oillywater

New member
Hey guys I’m new to all this stuff even owning a a boat so cut me some slack.
I have a 88’ force 125 that I don’t know how long hasn’t ran for I wasn’t getting sparked so I disconnected the magneto cable and now I have spark. I can get it to putt and run for about 2-5 second. Then it randomly turned on for about 12 seconds and then gave a loud pop like a backfire I think and shut off and put a lot of either soot or oil looks more like soot to me. Then I went to crank it again and it wouldn’t even putt. Seems like it wasn’t getting gas so I pulled the fuel pump didn’t take it apart since gasket was brittle blew through it which it was really had to blow thru still kinda is but better. And now it putt and turns on for a bit but then does the same think backfire and shut off. Also forgot to mention that I’d have a lot of gas dripping out of the carbs when I stop cranking the motor. I’ll post pics of old sparks
 
The backfire could be: too much fuel going into the motor? Sucking air can make it backfire(blown gaskets).
The plugs look normal.
The oil in the water: too much gas in the motor.
What it sounds like to me: the motors sucking air from bad gaskets, or the fuel pump diaphragm is bad.
Buy a rebuild kit and then try to start it.
Lots of oil in gas: the trying to start again and again and pumping the ball again and again pushes excess fuel into the motor, the gas evaporates and leaves the oil then that blows the oil out when it backfires.
Do a compression and spark test, post the results.
The port cover gaskets are the usual problem, one backfire can blow all 4 and that's real hard to find.
 
How can 1 backfire blow these 4 gaskets ???-----There are 4 separate crankcases in this motor.----Maybe check the flywheel key.
 
Jerryjerry05 said:
The backfire could be: too much fuel going into the motor? Sucking air can make it backfire(blown gaskets).
The plugs look normal.
The oil in the water: too much gas in the motor.
What it sounds like to me: the motors sucking air from bad gaskets, or the fuel pump diaphragm is bad.
Buy a rebuild kit and then try to start it.
Lots of oil in gas: the trying to start again and again and pumping the ball again and again pushes excess fuel into the motor, the gas evaporates and leaves the oil then that blows the oil out when it backfires.
Do a compression and spark test, post the results.
The port cover gaskets are the usual problem, one backfire can blow all 4 and that's real hard to find.
Click to expand...
Compression test
#1-150psi
#2-145psi
#3-145psi
#4-145psi
 
Flywheel key: Top of the motor is the flywheel.
It's held in place by the nyloc nut and 85# of torque.
Between the flywheel and the crankshaft is a key. The key is there to make sure the motor fires/sparks at the right time. Not all keys look like this.
If the key shears the flywheel slips and the timing will change.
It can make it miss or not fire right and not start.

Bought a new boat in 1988 had twin 88/85 Forces.
The first month.
Went fishing late in the afternoon and was getting dark and the stbd. motor failed, wouldn't start no matter what was done,.
The flywheel key sheared. I think the flywheel nut wasn't as tight as it should be.
A backfire can cause the problem and it can suck air and cause bad running.

I guess I should have elaborated: the backfire can blow the port cover gaskets and all 4 could be affected.
ayFNg1wo5JC67ZFZ036plMW8SdZJuhvgU9mgP2DOAqAO8y5Glm.jpg
 
Jerryjerry05 said:
Flywheel key: Top of the motor is the flywheel.
It's held in place by the nyloc nut and 85# of torque.
Between the flywheel and the crankshaft is a key. The key is there to make sure the motor fires/sparks at the right time. Not all keys look like this.
If the key shears the flywheel slips and the timing will change.
It can make it miss or not fire right and not start.

Bought a new boat in 1988 had twin 88/85 Forces.
The first month.
Went fishing late in the afternoon and was getting dark and the stbd. motor failed, wouldn't start no matter what was done,.
The flywheel key sheared. I think the flywheel nut wasn't as tight as it should be.
A backfire can cause the problem and it can suck air and cause bad running.

I guess I should have elaborated: the backfire can blow the port cover gaskets and all 4 could be affected.
View attachment 30398
Click to expand...
Update
Changed the fuel pump gasket and diaphragm along with port cover gasket and the x looking gasket between pump and port cover. Still won’t start. But still starts with starting fluid but back fires
 
You check the flywheel key?
Check for TDC? Remove top plug. Insert long screwdriver in hole, turn(by hand) till the screwdriver gets pushed back out as far as it will go, then front of the motor on top is the timing marker.
The marker should be on the flywheel mark ,one of the slashes. Which one is it on or near??
 
Jerryjerry05 said:
You check the flywheel key?
Check for TDC? Remove top plug. Insert long screwdriver in hole, turn(by hand) till the screwdriver gets pushed back out as far as it will go, then front of the motor on top is the timing marker.
The marker should be on the flywheel mark ,one of the slashes. Which one is it on or near??
Click to expand...
Seems to be at tdc to me couldn’t even put the screw driver in it. Does that mean I have to time it could the stator be installed wrong. Also the timing screw has been messed with the slot for the screw driver is messed up alittle
 
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