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1986 OMC IO 140HP engine wont stay running HELP

is there a certain way to adju

is there a certain way to adjust the fuel and air mixture screws? like in a old car it was turn them all the way in and then turn them 1 and a quarter turns out.
 
I recieved my manual but I got

I recieved my manual but I got the wrong one and I can't get the right one without my model number and I can't find it?
 
I just got one of those rpm me

I just got one of those rpm meters and I dont know where to put the green aligator clip?
 
"Model number should be on a s

"Model number should be on a silver sticker on the valve cover, if the boat builder put it there!
As for RPM meter, You got Red+, Black -, green Coil-."
 
I tried to set it and it still

I tried to set it and it still revs up how do I fix that?
 
"I suspect that You either has

"I suspect that You either has set the timing at 4 After TDC instead of 4 Before TDC, or the throtle plates are opened to much. The 3.0 GM has been unchanged for 20 or so years so You ought to be able to use almost any manual from 1976 to 2000 to set the engine. Have You set Youe meeter at the right setting 4cyl?"
 
"yes, but it still rev's u

"yes, but it still rev's up could it be a timming belt, chain, or could it be the fuel air mixture or the choke setting?"
 
I set it for 4 before TDC and

I set it for 4 before TDC and it still revs up.
 
Are the throtle plates closed

Are the throtle plates closed and throtle cable off the carburator? can You give me some rpm numbers where it runs? does it run at a steady higher rpm?
 
I set it between 800 and 850 a

I set it between 800 and 850 and it races to over 1000 I dont think that the throtle plates are closed yes I had the throtle cable off the carb. How do you adjust the fuel and the air mixture?
 
"Are You running with muffs, o

"Are You running with muffs, or in the sea. Due to back pressure running ashore may encrease the rpm. Do not adjust the fuel/air mix until boat is in the water."
 
I am running it with muffs bec

I am running it with muffs because I already got stuck in the water twice just today I had to be pulled in by a nice man who was just sitting in his boat right next to us (we didn't get 100 feet out)
I need to buy a new alternator. how do you adjust the fuel/air mixture in the water any specific way?
 
"Turn the mix screw all the wa

"Turn the mix screw all the way in, but carfull. Note how many turns You did. Then back it off 2,5-3 turns. Take a plastic hose, 0,5 meter, one end in the carrb thoat, one end in You ear. Normally the best setting is just when you hear suckling from the fuel. Too far in, suckling disappear, to far out, engine soots down. When You find the smoothest running point at low idle you are there. Take it ou and throtle up, Let the engine burn off old soot etc, idle for some 15 minutes, take out the sparks and check, They should be light brownish. Not white = too lean, not black = too rich. The basic setting mentioned above all depends on carb and engine condition, but you have to start somewhere. The best is to let an experienced mech do this.
What happened to the alternator?"
 
when we went out the engine st

when we went out the engine stoped and then we took it home and checked if we were getting 14volts from the battery when the boat was running and it was going from 12.55 and down. so we know that it is the alternator it is getting hard to find any kind of parts for the boat because of the year that is what sucks.
 
"Sierra used yo have alternato

"Sierra used yo have alternators that fits Your engine, but the link above did not work propely. However it should not be a problem. Test first that You have 12 volts going into the alternator field when ignition is on and engine not running!
It is the same cable system that provides current to the coil, perhaps You made some funny connections during Your ignition failure search!"
 
now it is backfiring from the

now it is backfiring from the carborator would that be from the timming?
 
"Either totally wrong timing,

"Either totally wrong timing, burned inntake valves or You have mixed the plug wires/fireing order (1-3-4-2). Unscrew the oil filling cap, or take off the valve cover, and take off the distributor cover. Turn the engine by hand until the valves on cyl one changes and one more turn!
The TDC mark at the front pulley should be in the biggest notch in the ign scale at the transmission cover, points just begin to open, rotor position towards No1 spark plug cable! May be easiest to turn engine when spark plugs are out!
If ignition is ok, take a comp test."
 
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