I'd love to see what you all think of the quality of my diagnosis. Here's the situation:
Basic 'what's working':
1986 Force 85hp
New/working iginition system (stator-to-spark plugs) have spark on all
127# compression all 3 cylinders
New Impeller, t-stat & tell-tale= great running temp
new Head cover Gasket and re-check (still in tact)
Currently runs up to 4,200 rpm
Cold starts on first crank (after squeezing primer bulb)
New and tested primer bulb
New end-to-end fuel lines and clamps, no obvious leaks
The clues -
Despite working primer bulb, can squeeze bulb forever and will not get completely hard - can squeeze it slowly down (engine smokes and is really hard to start if I sit and do this a while (that was last night).
Shortly after start enging begins to run rough, but does not kill.
Primer ball goes soft, after a few minutes, feels empty.
Adjusting low idle screws: Carb 1 & 3 respond immediately to changes,
carb 2 - engine runs same if screw is set closed or if set many turns open.
Squeezing the bulb will kill the engine at this point.
Going immediately to WOT, engine is rough accelerating up to speed, but does
'settle-in' to full WOT @ 4200rpm, running smooth on all cylinders (pretty sure).
after 20 sec & up to 4 minutes, engine boggs-comes back up-boggs etc 'till finally it dies unless I pull throttle back to idle speeds where it runs, though roughly.
during the WOT bogg delicately squeezing the bulb can help, but often kills the motor.
At the end of all these adventures, bulb is always soft.
What do you think is the problem?
my 'Chumps' diagnosis:
Float needle/valve/ is not closing on #2 carb. This allows the carb to over-supply the #2 circuit with fuel and does not allow the bulb to acheive a steady pressure. As well, at WOT, the #2 cylinder hogs the gas supply as the float never closes when the bowl is full and sooner or later all the carbs run low on gas & engine bogs. If I let it sit at low/rough idle for a few seconds, she'll go WOT again for a short while - this I can do over and over again.
Am I right???
Basic 'what's working':
1986 Force 85hp
New/working iginition system (stator-to-spark plugs) have spark on all
127# compression all 3 cylinders
New Impeller, t-stat & tell-tale= great running temp
new Head cover Gasket and re-check (still in tact)
Currently runs up to 4,200 rpm
Cold starts on first crank (after squeezing primer bulb)
New and tested primer bulb
New end-to-end fuel lines and clamps, no obvious leaks
The clues -
Despite working primer bulb, can squeeze bulb forever and will not get completely hard - can squeeze it slowly down (engine smokes and is really hard to start if I sit and do this a while (that was last night).
Shortly after start enging begins to run rough, but does not kill.
Primer ball goes soft, after a few minutes, feels empty.
Adjusting low idle screws: Carb 1 & 3 respond immediately to changes,
carb 2 - engine runs same if screw is set closed or if set many turns open.
Squeezing the bulb will kill the engine at this point.
Going immediately to WOT, engine is rough accelerating up to speed, but does
'settle-in' to full WOT @ 4200rpm, running smooth on all cylinders (pretty sure).
after 20 sec & up to 4 minutes, engine boggs-comes back up-boggs etc 'till finally it dies unless I pull throttle back to idle speeds where it runs, though roughly.
during the WOT bogg delicately squeezing the bulb can help, but often kills the motor.
At the end of all these adventures, bulb is always soft.
What do you think is the problem?
my 'Chumps' diagnosis:
Float needle/valve/ is not closing on #2 carb. This allows the carb to over-supply the #2 circuit with fuel and does not allow the bulb to acheive a steady pressure. As well, at WOT, the #2 cylinder hogs the gas supply as the float never closes when the bowl is full and sooner or later all the carbs run low on gas & engine bogs. If I let it sit at low/rough idle for a few seconds, she'll go WOT again for a short while - this I can do over and over again.
Am I right???
