Force 120 Carb Rebuild?

[stssa]

97 Force is a little hard to start when its cold. Bulb gets hard after 4 squeeze. Choke clicks so I assume it works. Engine starts and dies the same second. Crank it again, it will start and die again. I give it full throttle and shift to neutral and try again it will start and die again. Sometimes it takes 5 or 6 tries to start the engine. Once it starts it Idles very smooth.
Also, When engine is warm if I shut it off for sometime and try to start it, it starts and dies with a popping sound like engine backfire. Second try always starts and idles smooth.
Maybe the carbs need rebuild. Should I switch to a higher octane like 93 and see if it makes a difference? I just ran a bottle of Seafoam thru the full fuel tank. I was spraying some Seafoam deep creep into pistons overnight and run it for 5 minutes the next day. I did this procedure for 3 days. I used spark plug holes to spray the deep creep. Should I spray some deep creep into the carbs while its in water? Spark Plugs are new so I dont think its got anything to do with them. Its a little embarrsing at the boat ramp, cranking it for 5 minutes to start this thing you know.

P.S. I was wondering If I decide to rebuild the carbs, Can I use NAPA 18-7037 Or Should I get the expensive kit 809807A1. DOes anyone know what is included in either kit?

 

[pnwboat]

Re: Force 120 Carb Rebuild?

Do you try starting with the throttle in the neutral fast idle position?

 

[bman1bpm]

Re: Force 120 Carb Rebuild?

I agree with previous post, make sure you're in fast idle. With my engine on a cold start I put it in fast idle choke the engine and turn the key for a second, then let go of the choke and crank it. Should fire right up.

Running high octane gas is a waste in these motors, I run 89 or 87.

If you're already using that starting procedure I'd pull the carbs apart and clean them. All you really need is a new carb bowl gasket, they're cork part FO15623 . The fuel bowl screw gaskets FO5323 (two for each carb). And the gaskets from carb to the engine if yours are old F440906. Any merc dealer can get them.

 

[roscoe]

Re: Force 120 Carb Rebuild?

There is no conventional choke on that motor.
There is a fuel enrichment valve, that releases fuel directly into the intake manifold.

Open fuel tank vent

Check the kill switch, place in "run" position

Squeeze fuel primer bulb till firm.

Advance the throttle 3/4 way, without putting it in gear. -- This is done by either pushing a button in the center of the controls, or pulling the shift handle toward the driver, or raising the fast idle lever, all depending on what control unit you have.

Activate the choke (fuel enrichment valve) by pushing in on the key. The valve is only open while the key is being pushed in.

Turn the key to start while continuing to hold the key in.

Release the key and choke when it starts.

3-5 seconds of "choke", is usually enough.

Be ready to pull the throttle back toward the idle/neutral position, when the engine starts and the revs increase.

Continue to pull the throttle back as the engine warms up.

You should not have to use the choke much, if at all, once the engine has warmed up.

Engine should start within 10 seconds of turning the key.

Don't use higher octane fuel.