6hp tohatsu won’t turn on

Jhayes780

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Verified spark and gap
Fuel is getting to the carb
There’s some smoke when I pull the string and engage the flywheel
New gas
New oil
New impeller

Less than 10 total hours and it won’t turn on?

Any help appreciated
 

Scott Danforth

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Is there an MOB switch?

Did you hit something shearing the flywheel key?

Are you pulling fast enough?
 

Jhayes780

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Also sorry for the title iPhone decided to auto correct

Pulling hard enough yes
Flywheel looks good
Mob??
 

Jhayes780

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I do notice the fuel filter will not fill up no matter how much I pump. Even if it starts spilling out of the overfill tubes
 

MattFL

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It's OK if the filter still has some air in it. If you open the drain on the carburetor, does fuel come out? Try opening the throttle, spray in a little starting fluid, close the throttle to about 1/4 throttle then give it a good pull. If it won't start with starting fluid then the next things to check are spark, timing and compression.
 

Jhayes780

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It's OK if the filter still has some air in it. If you open the drain on the carburetor, does fuel come out? Try opening the throttle, spray in a little starting fluid, close the throttle to about 1/4 throttle then give it a good pull. If it won't start with starting fluid then the next things to check are spark, timing and compression.
Compression is good how do I check timing
 

MattFL

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Before you get into timing, what is the history of the motor? Was it put into storage with gas still in it? Did you try some starting fluid? It's a whole lot easier to give it a shot of fluid and see if it fires, than taking things apart to verify timing. With a motor that new, if it's got spark and compression then most likely the problem is a clogged up carburetor.

That said; to check mechanical timing, to be sure the flywheel didn't shear the key and slip. Pop the valve cover and look at the cam while you turn the flywheel to TDC. Every other revolution the valves should both be closed when the TDC mark on the flywheel lines up with the indicator. This will help:


But like I said above, try the starting fluid first. If it runs for a moment with starting fluid, then the timing is fine.
 

Jhayes780

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Before you get into timing, what is the history of the motor? Was it put into storage with gas still in it? Did you try some starting fluid? It's a whole lot easier to give it a shot of fluid and see if it fires, than taking things apart to verify timing. With a motor that new, if it's got spark and compression then most likely the problem is a clogged up carburetor.

That said; to check mechanical timing, to be sure the flywheel didn't shear the key and slip. Pop the valve cover and look at the cam while you turn the flywheel to TDC. Every other revolution the valves should both be closed when the TDC mark on the flywheel lines up with the indicator. This will help:


But like I said above, try the starting fluid first. If it runs for a moment with starting fluid, then the timing is fine.
Ok ya I just pulled the carb apart and put it in an ultrasonic cleaner. I don’t think that’s it. Where exactly. Should I spray the starter fluid
 

Jhayes780

Petty Officer 2nd Class
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Messages
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Before you get into timing, what is the history of the motor? Was it put into storage with gas still in it? Did you try some starting fluid? It's a whole lot easier to give it a shot of fluid and see if it fires, than taking things apart to verify timing. With a motor that new, if it's got spark and compression then most likely the problem is a clogged up carburetor.

That said; to check mechanical timing, to be sure the flywheel didn't shear the key and slip. Pop the valve cover and look at the cam while you turn the flywheel to TDC. Every other revolution the valves should both be closed when the TDC mark on the flywheel lines up with the indicator. This will help:


But like I said above, try the starting fluid first. If it runs for a moment with starting fluid, then the timing is fine.
Also don’t know too much about the history it was running for the guy I got it from and I believe he let it sit and now I can’t get it to start
 

MattFL

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For the starting fluid; if that's like my Tohatsu 6HP then there's a metal screen over the air intake, facing downward, on the front of the carburetor. Open the throttle to full throttle, spray the starting fluid up into that screen. Maybe a 1-second spray. Then close the throttle to about 1/4 and give it a few pulls. If it sputters or starts for a second, then the carburetor is the problem. The passages in those carburetors are itty bitty. The ultrasonic cleaner is a great start, but also spray carb cleaner and compressed air through every hole, especially the tiny ones. Take the fuel screw out and spray through there too. Wear safety glasses, carb cleaner will wreck your eyes and frequently comes back to you when spraying into the holes of a carburetor. If the guy said it was running fine when it went into storage, then 95% chance the carburetor is the problem.

Side note --> When you're trying to start it normally, you're using the choke right?
 

Scott Danforth

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starting fluid kills 2-strokes since it doesnt have oil. you should spray a mix of oil/gas in a 2-stroke.
 

MattFL

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starting fluid kills 2-strokes since it doesnt have oil. you should spray a mix of oil/gas in a 2-stroke.
Are we talking about a 2T or 4T? I was assuming a 4T. Also I've used starting fluid with 2-strokes many many many times, it's fine. When I was a teenager back in the early 90's my buddies boat had an old Mercury 150 v6 2-stroke that refused to cold start, so we kept a can of starting fluid in the boat for the first start of the day. We must have driven that thing half way around the world. Wait tables at night, pool our tips in the morning to fill the boat, go wakeboarding or fishing all day, rinse and repeat. He had a boat and no truck, I had a truck and no boat, we got along really well. :)
 

Jhayes780

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For the starting fluid; if that's like my Tohatsu 6HP then there's a metal screen over the air intake, facing downward, on the front of the carburetor. Open the throttle to full throttle, spray the starting fluid up into that screen. Maybe a 1-second spray. Then close the throttle to about 1/4 and give it a few pulls. If it sputters or starts for a second, then the carburetor is the problem. The passages in those carburetors are itty bitty. The ultrasonic cleaner is a great start, but also spray carb cleaner and compressed air through every hole, especially the tiny ones. Take the fuel screw out and spray through there too. Wear safety glasses, carb cleaner will wreck your eyes and frequently comes back to you when spraying into the holes of a carburetor. If the guy said it was running fine when it went into storage, then 95% chance the carburetor is the problem.

Side note --> When you're trying to start it normally, you're using the choke right?
Yes using choke
 

Jhayes780

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You would spray starting fluid in the carb...
Well yes I know but engine where I can pull the cover off, and the carbs are exposed when starting, I was just wondering where to spray it on these tiny carburetors without having to pull it apart
 

ThomW

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I will say that my father in law has a tohatso 6hp motor and it wouldn't start every year after the winter. As mentioned above, the carb has a few really small holes, namely the low idle jet. In order to get it cleaned and running I actually had to take a really thin piece of wire and poke it through the hole in the jet while cleaning it. I'd also check the condition of the fuel lines...if there are starting to breakdown it will allow small pieces into the carb and block things up.
 

ThomW

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Well yes I know but engine where I can pull the cover off, and the carbs are exposed when starting, I was just wondering where to spray it on these tiny carburetors without having to pull it apart
You should be able to get it into the carb via the air box that is right in front of the carb...
 
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