Fishtigua
Well-Known Member
Early 2.5/3.5 had tanks that could not feed fuel when nearly empty. The last few inches wouldn't get to the fuel cock. Try filling it up.
Help with my first outboard motor please!
- Thread starter nexus180
- Start date
Happy Dayz
Well-Known Member
? Well, early on I mention both the cut out switch and how to test for spark - so not everyone is looking at fuel ?.
O/P admits he is new to outboards, I actually wonder (with all due respects) if his starting technique is at fault? I also wonder is he selecting reserve not the 'normal' setting on his fuel tap (which iirc from small Tohatsu has this option).
For a few quid on eBay you can get a test plug cap that the you plug in between the plug and the original plug cap. Very useful device as it aids spark energy being seen, especially if in brighter daylight.
I really would advise to disable the emergency stop button, pull the wires off and join them together in some way, such as a short wire link.
To start from cold, ensure your engine is firmly secured to test jig or transom. have at least 1/2 a tank of fresh fuel. neutral gear is selected, choke all the way closed, open fuel valve. Open bleed screw on fuel cap. Throttle at 'start' position.
About 3 or 4 pulls should do it, if it fire's up open the choke fully., let it fast idle for a few minutes, then see if it ticks over.
If you have the choke combined on the twist grip then, turn it to this position and give a few pulls.
One trick to clear suspected blocked jets is to muffle the air intake with your hand after removing the air filter, pull the starter chord several times. You should feel the suction which is what you are using to suck the jets clear, be well aware of spinning part hazards like flywheel and prop of possibly causing you a nasty injury!
If your using an external tank make sure to push hard on the fuel pipe connector, and it has the right one otherwise the integrated spillage valve will not release the fuel.
The fuel pump is worked off crankcase pressure acting on a diaphram, you said earlier no fuel was released from the float bowl when the bleed screw was removed.
Try again after doing as suggested above, a possibly an air lock might be the fault. To prove the pump - which is used on the gravity tank or external tank, disconnect fuel line from carb, take sure ht lead off the spark plug keep it well clear (or you could ignite any released fuel). If you don't see fuel when engine is turned over then work your way back to the tank, if you do then look at float needle adjustment, you have to get fuel into that bowl to get anywhere, but to much fuel and flooding can cause problems to.
Alan
Happy Dayz
Well-Known Member
A further thought is the safety switch that prevents engine starting while in gear
Alan
Alan
John100156
Well-Known Member
Some good advice but before he concentrates on carb/fuel (don't get me wrong, often that is the probable cause read on) just pull out the spark plug, place it firmly against the motor casing to earth it (or tie wrap it there) then crank, if there is a spark you will see it and know all electrical continuity is OK.
Once you know the electrics are working OK, move onto fuel. My grandkids brought their ATV around last weekend, the coil was at fault, I replaced it, it still didn't work, so I stripped down the carb and as expected crud in the bowl, jets all clean but blown through anyway, cleaned them, still didn't start, it turned out someone had wound the mixture and idle screws fully in (I know should have checked them before taking carb off). I did the usual, would out mixture about 1.5-2 turns and idle out a bit and it fired-up and ran perfectly. Nice feeling that.....
So for me, it's always electrics/spark first, then carb/fuel... ;-)
Once you know the electrics are working OK, move onto fuel. My grandkids brought their ATV around last weekend, the coil was at fault, I replaced it, it still didn't work, so I stripped down the carb and as expected crud in the bowl, jets all clean but blown through anyway, cleaned them, still didn't start, it turned out someone had wound the mixture and idle screws fully in (I know should have checked them before taking carb off). I did the usual, would out mixture about 1.5-2 turns and idle out a bit and it fired-up and ran perfectly. Nice feeling that.....
So for me, it's always electrics/spark first, then carb/fuel... ;-)
Happy Dayz
Well-Known Member
If you Google Tohatsu 4hp service manual, you should be able to find a copy of it into PDFs format, this will give be you the circuit diagrams as well as in some cases test procedures.
Do the same for owners manual to get more tips
Alan
Do the same for owners manual to get more tips
Alan
No Regrets
Well-Known Member
I have one of these and it's a good unit!
Take the screwdriver from the toolkit and insert it into the spark plug cap. Put a finger on it and see if you get a shock when the cord is pulled (not if you have a pacemaker fitted!!!) It's non lethal don't worry.
Or, hold the tip near a metal object and see if a spark jumps to it.
If the fuel is on, and the float chamber screw is open, fuel will flow out freely assuming there's enough in the tank.
Assuming you have adequate fuel and a spark, it will run (because it did when you last used it!) unless the carb is still dirty. Eezi start will confirm if it's fuel, just spray a bit into the intake and it should fire up momentarily.
This is unlikely to be expensive anyway, so consider the dealers offer.
Take the screwdriver from the toolkit and insert it into the spark plug cap. Put a finger on it and see if you get a shock when the cord is pulled (not if you have a pacemaker fitted!!!) It's non lethal don't worry.
Or, hold the tip near a metal object and see if a spark jumps to it.
If the fuel is on, and the float chamber screw is open, fuel will flow out freely assuming there's enough in the tank.
Assuming you have adequate fuel and a spark, it will run (because it did when you last used it!) unless the carb is still dirty. Eezi start will confirm if it's fuel, just spray a bit into the intake and it should fire up momentarily.
This is unlikely to be expensive anyway, so consider the dealers offer.
nexus180
New Member
FIXED! Thanks all for the suggestions.
In case it helps anyone else, here's what fixed it. I tried again to check for a "spark" and couldn't see one - but I must have missed it as I've managed to get the engine started anyway. As suggested, I took the fuel feed pipe off the carb and turned the fuel tap on - fuel came flowing out as it should. Having noticed that when I undid the fuel drain screw from the bottom of the carb no fuel came out, I figured that fuel seemed to be flowing up the feed pipe, but didn't seem to be finding its way thru the carb and out of the bottom. On that basis I dismantled the carb and checked that the brass valve where the fuel enters the carb was clear all the way thru (it was) - which then led me to the float valve. I've never removed this, but it looked pretty dirty so I did and cleaned it up before squirting carb cleaner down the pipe behind it. I then rebuilt it all and checked the carb float height, which seemed too low so I adjusted it.
To my amazement the motor then started no problem - and I noticed the fuel filter is now pretty much full of fuel (whereas it was only about 20% full). Phew. Thanks again for all the help.
In case it helps anyone else, here's what fixed it. I tried again to check for a "spark" and couldn't see one - but I must have missed it as I've managed to get the engine started anyway. As suggested, I took the fuel feed pipe off the carb and turned the fuel tap on - fuel came flowing out as it should. Having noticed that when I undid the fuel drain screw from the bottom of the carb no fuel came out, I figured that fuel seemed to be flowing up the feed pipe, but didn't seem to be finding its way thru the carb and out of the bottom. On that basis I dismantled the carb and checked that the brass valve where the fuel enters the carb was clear all the way thru (it was) - which then led me to the float valve. I've never removed this, but it looked pretty dirty so I did and cleaned it up before squirting carb cleaner down the pipe behind it. I then rebuilt it all and checked the carb float height, which seemed too low so I adjusted it.
To my amazement the motor then started no problem - and I noticed the fuel filter is now pretty much full of fuel (whereas it was only about 20% full). Phew. Thanks again for all the help.
Bigplumbs
Well-Known Member
Well done I bet you now feel pleased with yourself
Dennis
Dennis
John100156
Well-Known Member
Well done, best way to get to know your equipment when something goes wrong. Good feeling when it starts!