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gjgm

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Tohatsu 3.3 2 stroke.. yesterday Ifully opened it up and at the highest revs it died. Now it will throttle ok in neutral, but in gear if I increase speed above tic over, it cuts out. This makes for slow progress !
So, what am I looking for, please
 
gjgm said:
Tohatsu 3.3 2 stroke.. yesterday Ifully opened it up and at the highest revs it died. Now it will throttle ok in neutral, but in gear if I increase speed above tic over, it cuts out. This makes for slow progress !
So, what am I looking for, please
Click to expand...

Classic symptoms of blocked main jet 9 times out of 10.
Whip off the carb, remove main jet (the one in the middle pointing down into the float bowl). Clean the jet (do not poke anything hard down it: air line is best means). Give carb a general clean, check fuel flow and quality.
 
macd said:
Classic symptoms of blocked main jet 9 times out of 10.
Whip off the carb, remove main jet (the one in the middle pointing down into the float bowl). Clean the jet (do not poke anything hard down it: air line is best means). Give carb a general clean, check fuel flow and quality.
Click to expand...
Having done this about three engine hours ago at least I know how to do it ;)
 
gjgm said:
Having done this about three engine hours ago at least I know how to do it ;)
Click to expand...

Sounds like you might have some sort of crud in the fuel. Water's the most likely culprit. At risk of teaching grannie to suck eggs, take care to remove float bowl without spilling contents: good chance you will then see whatever it is in the bottom of the float bowl.
 
gjgm said:
Tohatsu 3.3 2 stroke.. yesterday Ifully opened it up and at the highest revs it died. Now it will throttle ok in neutral, but in gear if I increase speed above tic over, it cuts out. This makes for slow progress !
So, what am I looking for, please
Click to expand...

As suggeted clean carb again

Check/clean fuel filter

flush out tank

Check fuel flow to carb

BUT BUT BUT

so often symptoms that indicate a dirty carb or a fuel problem turn out to be due to a dodgy plug .... so try a new plug.
 
VicS said:
As suggeted clean carb again

Check/clean fuel filter

flush out tank

Check fuel flow to carb

BUT BUT BUT

so often symptoms that indicate a dirty carb or a fuel problem turn out to be due to a dodgy plug .... so try a new plug.
Click to expand...
Thanks all, got a few hours to play I see ;)
 
I have this engine (3.5) and agree it must be restriction of fuel flow.
Can I be cheeky and ask if anyone has a carburettor for a Tohatsu 3.5 as well? Cheers Jerry
 
Before you start stripping anything down this is also the exact symptoms you get if you forget to open the air inlet valve on the fuel tank. No need to ask how I know!
 
CreakyDecks said:
Before you start stripping anything down this is also the exact symptoms you get if you forget to open the air inlet valve on the fuel tank. No need to ask how I know!
Click to expand...
Done that.. several times ;)
What is odd, to me, is that it was only after I tried 5 seconds at full throttle that this happened, and it is ok, as long as it is out of gear. Why is there a fuel problem only when in gear ?
 
Not specific to your engine but similar symptoms can be caused by a variety of reasons: float bowl sticking and preventing fuel refilling fast enough, airlock in fuel line, blocked fuel filter, poor compression from insufficient oil in fuel (2 stroke), choke left/stuck on, failed crankshaft oil seal (2 stroke), loose HT lead or HT lead breaking down, points/condenser faulty, advance/retard not working properly (non CDI engines,) split diaphragm in fuel pump or carburettor. There are probably other possible causes too but at various times on a variety of engines Ive experienced most of these.
 
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