1984 force 125 back fire now wont run?

[slimmer57]

I still have spark on all cylinders and it turns over but turns over extremely slow not even close enough to start, when it back fired it caused a little fire which was put out immediately.

What should be my next step? starter is new and as long as spark plugs are out it will turn over fast but as soon as spark plugs are in wont turn over, head gasket it still good, And fuel pump is still good, It started up right after the small fire, and i took it to the ramp, brought it home to flush it and no start.? battery is good and even swapped it to a new battery that fully charged still nothing? some time intermediately it will turn over fast until i let off the key once i try again it is back to being slow

I also checked wiring no burned wired or even messed up wires

 

[racerone]

How did it run for you last season ?-----Checked the flywheel key ?

 

[slimmer57]

was running fine this morning then this happened I don’t know if starter maybe went out as well? But fly wheel key is perfect

Flywheel turns everything togeather

 

[racerone]

Check the flywheel key.

 

[slimmer57]

Check the flywheel key.

I took it off it’s still how it’s sappouse to be

 

[jerryjerry05]

Compression test? all should be close to each other.
Backfire: one backfire or cough even stutter can blow the port cover gaskets, causing the motor to suck air.
Slow turning: bad connection on the battery or starter or cables? The starter can be bad/dirty. A new Chinese starter can be bad right out of the box.

 

[slimmer57]

Compression test? all should be close to each other.
Backfire: one backfire or cough even stutter can blow the port cover gaskets, causing the motor to suck air.
Slow turning: bad connection on the battery or starter or cables? The starter can be bad/dirty. A new Chinese starter can be bad right out of the box.

Each cylinder is at 105-110 which is what it was before when it was running good

 

[slimmer57]

So I put some oil in the cylinders lined em up and spun it over I got it to start but it will immediately backfire and cut off after starting the will be hard to start again

 

[racerone]

Backfiring is usually a sign of timing issues.----That is why I suggested an issue with the key.-----I can not see or touch your motor.----Good luck sorting it out.

 

[jerryjerry05]

Backfiring is a sign of the motor sucking air.
I can see in the pic why the comp is low. Normal comp is 145-160
Look at the gauge, it says Pittsburgh(harbor freight) cheap tools give faulty readings. The good news is all 4 are close to each other.
Now back to the backfire: most outboards don't jump time like an automotive motor.
The first backfire probably blew out the port cover gaskets and now it sucks air so bad it only gets worse.
If you can get it to run?? rev it up if possible, spray starting fluid around the intake side and if that makes a difference in the way it runs?? then the gaskets need replacing.
Carb base and intake gaskets can be affected by a backfire.
You have 4 port covers, check the edges and see if there are and gaskets sticking out the side??
Pull the fuel pump port cover and inspect that.