tohatsu 3.5 won`t start

[midnightstar]

hey there!
my outboard wont start.just replaced the spark plug and cleaned the carborator.
electrical problem?

[mangomuffins]

fuel...spark...compression...

That's basically it.

mm

[midnightstar]

i was thinking its the sudden death switch

[Easterly-30]

Try disconnecting the kill switch.

[S/V Antares]

I have a 3.5- 4 stroke. Left it on the stern rail for 6 weeks without using and it would not start. Took the carb apart and found what can only be discribed as Green Jello in the bowl. Gas simply does last with all the ethenol and other junk in it. If you have spark check the carb.

[midnightstar]

how do you disconnect the killswitch?
i couldn`t figure out how to by-pass it?

[TexSail]

Did you empty the old fuel and put fresh in it?

[midnightstar]

the old fuel was only 2 weeks,is that old?

[midnightstar]

how do you disconnect the killswitch?
i couldn`t figure out how to by-pass it?

[SilentOption]

Agree on mess in Carb. Just draining it wont do once the damage is done. If it was sitting long I'd take the carb completely apart. Pay attention to the fuel jet its probably microscopic at that horsepower.

That said I would first, or once again check spark, make sure fuel is getting to the carb, make sure fuel is getting to the plug. Try to flood it by pumping the line hard and over prime. Then pull the plug and make sure fuel is getting into the cylinder.

If the plug is dry and clean then its probably not getting through the carb. Kill switch is another obvious thing to check as welll as making sure its really in neutral. Maybe its still in gear. My small merc was starting in gear last week before we took it in.
Parts are so small on these motors things get bent and wires get broke.
If you haven't already, dump your tank and try new gas. An expensive (3 or 4 beers) troubleshooting step I know but Its worth trying before taking the motor to a mech.
Just saw most ideas have been brought up. Having the obm not start is so common my 12 year old knows all the steps.
Good luck

[S/V Antares]

Yup. Silent has been there. I have been working on this stuff forever and have never seen this type of issue happen so fast. You are correct about the microscopic jets. I could not clear mine even. Most of the jets are sealed off with plugs and I gave in. Bruised my ego to buy a carb for a 1 year old engine.

Midnightstar. Follow the 2 wires from the kill switch One go's to the coil and one goes to a ground on the block. There is a connection on the coil wire that you can easily disconnect which effectly eliminates the switch.

FYI my Tohatsu has no neutral safety and will start in gear. Don't know about the Merc (Built by Tohautsu)

[Ex-Calif]

This thread might help -

Wake Up The Mechanics - Outboard Challenge

Good tips on the kill switch and the in-gear switch (if installed)

[Easterly-30]

If I think water has gotten into the cylinder, I drain the carburator bowl to be sure there is no water trapped in it. Then, I take the plug out, spray WD-40 into the plug hole, give it a few tugs to clear the cylinder, and put a clean dry plug in. It usually starts right up.

[sabray]

I disasemble and clean the carb 4 maybe 6 times and all is well for 8 months. Adding an in line filter a real filter helps and additives. A few years ago while rowing ashore with a nissan dangling on the back of the dink. My at the time 4 year old looks at a neighboring dink with owner aboard and says look dad he has a Damn Nissan too. Really though the filter helps and the additives. Not Nissans fault I can't keep my fuel ultra virgin.

[Easterly-30]

That 4 year old comment was hilarious. Even better than just an in-line filter is the filter with a water separator. Small outboards usually expect to be using hi-octane fuel too.