1992 Force 70 Abruptly dies

[scubadave1973]

I have a 1992 Force 70, bought back in march , not sure how long it sat, ran fine on ears in yard, took to the water and ran good at idol, went to come up on plane and suddenly died, got home, I put new fuel lines on it from tank to carb, pulled carb and cleand float bowl and jets, new gapless plugs, wires, coils and CDI box, and now, this is what it's doing ...

 

[racerone]

Running on 2 of 3 cylinders?

 

[scubadave1973]

It's backfireing through the carb, either reeds or compression ,

 

[roscoe]

It's backfireing through the carb,

Usually means it's running too lean. open it up another 1/4 turn and see what it does.

 

[scubadave1973]

I've went all the way in, then out 1 full, then did 1/8 turns from there, it still wants to do it, can manually work the butterfly valve by hand and have to work on getting it up to WOT and sounds perfect , but at idol, it SUX

 

[Mc Tool]

Sounds to me like you need to have another go at cleaning the carb , particularly the idle and transition orifices and air bleeds . You really need to poke out all the orifices ...bit of thick fishing nylon or a bristle off a brush ,and blast out all the holes with aerosol carb cleaner or degreaser . You may have to remove some welch plugs to get at them all, and thusly you will need a carb kit .
Then do the link and sync . Whats the compression like (and dont just say "good") they gotta be at least 110 psi (125 - 150 is best ).

 

[scubadave1973]

checking Compression and reeds are next, has new plugs, wires, coils and CDI and fuel lines, might be carb being it had the GRAY fuel hose on it when i got it

 

[Mc Tool]

Yeah , stumbling off idle really sounds like an idle / transition issue

 

[scubadave1973]

What's crazy is, 1st time out it idoled fine, when to get up on step and it just lost power and died, got it to idol back to dock and havent gotten it right since, everyone was pointing to power pac, so all that is new, so I will pull carb and tear down and soak it.

 

[racerone]

Perhaps throttle plate is opening too soon.