1986 35 hp Merc Sputters But Wont Start

aMeyers11

Petty Officer 2nd Class
Joined
Feb 4, 2019
Messages
113
Hi everyone. I recently tried to get my 35 hp merc going, but it wouldnt start. It would sputter up and act like it wanted to run for a couple seconds but would soon die. It seemed to backfire and pop quite a bit. Lots of smoke when it started too.(50:1 synthetic mix). I made sure it was primed with vent open. I found that the electric choke doesnt work, but choking it manually didnt seem to make a difference. Priming while starting made no difference. To me it seemed like it was flooding as I had to wait a bit between tries for it to fire. I noticed a little gas coming out of the exhaust. I also noticed a little gas dripping from carb but i didnt see where from though. Is there an idle adjustment screw or a throttle adjustment I can maybe make? Or should I just be going ahead and cleaning and rebuilding the carb? Any help would be appreciated, thank you!
 

aMeyers11

Petty Officer 2nd Class
Joined
Feb 4, 2019
Messages
113
Also I should add that I was giving a bit above idle throttle using the neutral throttle button on my controls. I tried many different throttle positions but none kept it going
 

aMeyers11

Petty Officer 2nd Class
Joined
Feb 4, 2019
Messages
113
Fuel is like a couple week old premium(no ethanol) with stabalizer and 50:1 synthetic 2 stroke mix. I did replace the flywheel becuase the previous one was missing magnets. I know it has spark but I havent tested the strength or made sure that it's not intermittent. Bad timing could also be a possibility? I did find the idle mixture screw last night and found that it seemed to be quite far out so that might be why it was possibly flooding. I seated it and went 1.5 turns out. I plan to try to fire it up again tomorrow. I will also check to make sure I'm getting good consistant spark. Thanks for all of the help!
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,359
Does this Flywheel only fit one way? key in crank-shaft?
If you did not adjust the timing/advance setting and it worked before; it should now
Did the Stator get damaged maybe? you said you lost magnets
 

aMeyers11

Petty Officer 2nd Class
Joined
Feb 4, 2019
Messages
113
The flywheel is keyed onto the crankshaft so the timing should be the same as before, but when I received a new flywheel I had to assemble it. This involved bolting the keyed portion that goes around the crankshaft to the center of the flywheel. I used my old flywheel as reference to see where the key slot should be in relation to the magnets. I believe I got it right but it could be slightly off. I purchased the motor knowing the magnets came off. The previous owner gave the magnets too me but I accidently broke one, DOH! Hence the new flywheel. Previous owner said it ran good before it lost spark. I suppose it is possible the loose magnets damaged the stator? I also noticed with the flywheel off that the stator had a slight amount of rust or varnish forming on the edge. Should I have lightly sanded it? Tonight I plan to try and run it again with the idle mixture screw adjusted. Hopefully the mix was just too rich. But we shall see. If that doesn't go well I will check the spark consistancy and strength. From there I should know ignition or fuel issue? If the spark seems weird I will pop the flywheel off and test the ignition system. Hopefully it checks out though. I will hopefully post back with results tonight! Thanks
 

aMeyers11

Petty Officer 2nd Class
Joined
Feb 4, 2019
Messages
113
Alright the wisconsin weather didnt cooperate tonight, so I didnt get to try and run the motor. I did do a little more looking into the electric choke and I'm even more confused now. I'm going to make a new post regarding that. Will post back here as soon as i try to run the motor again.
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,359
A slight amount of rust is okay, if you want to clean it....a little wire-brush maybe a better tool to use & apply a small amount of wd40 or such to prevent rusting.
You could also put in some new plugs (look up what are the best one for your motor)
 
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