hard start/carbs/idle/120hp, help please!!!!

Joined
Jul 5, 2009
Messages
6
Back again!!! Bought a 1994 bayliner with a 94 force 120, price $1,100 for all with trailer from a pawn shop :). Motor ran good when purchased, boat had been sitting for unknown time. While running in my driveway for a few minutes all of a sudden it shook, coughed, sputtered and died. Figured it might have been old gas.

Emptied tank, changed all fuel lines, installed a glass inline filter, replaced filter on motor. Installed new fuel diaphragm, took out carbs, soaked, removed jets, cleaned all passages as best as i could (DID NOT REBUILD), installed new plugs and wires, fixed some worn plastic boots coming out of stator. Motor cranks good, but will only start opening the butterflies a little bit and will not idle.

Here is what i see. Motor has good spark and compression is good all cylinders between 150-160. Bogs when trying to get on plane but once running at WOT and putting my hand over the top carb will not kill the motor, bottom will. Did find nut on timing linkage under flywheel loose, retimed. Activating elec choke solenoid or spraying starting fluid doesnt help. Noticed floats are off according to my Official Factory force service manual, but dont have both tabs to adjust floats like manual says. Should i rebuild? carbs look too simple to waste money, plus it ran ok when i got it, started up and idled fine. HELP!!!!!!!!!!!!!!!!!!!!!!!!!!
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: hard start/carbs/idle/120hp, help please!!!!

Take a look at the reeds that are mounted in the block under the carburetors. You may have a broken or bent reed. Double check all of the hoses that come off of the back portion of the block by the carbs. May also have a vacuum leak.
 
Joined
Jul 5, 2009
Messages
6
Re: hard start/carbs/idle/120hp, help please!!!!

thanks for the reply!!! i have examined reeds and they look good, even checked their flexibility and they are nice and firm and seem to seat good. They dont look that old. I have examined all the vaccuum hoses that go to the intake and changed them/checked ball valves. the ones on the side of the block for the fuel recirculation system i have not checked. Could it be a clogged filter on the fuel recirculation system not allowing the unburnt fuel to come back around?

Like i said i am not totally convinced its carbs, since it ran before it coughed and sputtered. How can i check for a vacuum leak? where should i hook up a gage and what should it read?
 

john from md

Commander
Joined
Apr 13, 2008
Messages
2,184
Re: hard start/carbs/idle/120hp, help please!!!!

If your engine has a fuel recirculation circuit (hoses on side and under carb and intake) You need to clean this out well and make sure the orifice under the number three carb is not plugged. When this system is plugged, your idle will be off and starting will be hard.

John
 
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