The primer bulb & hoses got holes so i replaced them but now fuel is not getting into the engine, I squirt petrol down the carb & it will run briefly so it is not getting petrol. I have had the carb apart several times & there is no gunk blocking the passageways etc & the membranes all look good (no holes etc). I am stuck, when I prime it the petrol fills the bulb & goes back down the outlet tube back to the tank. In this screenshot https://trademe.tmcdn.co.nz/photoserver/full/362631214.jpg I have marked the X brass thing (next to hole 4) I think petrol needs to go through that & up the tube into the bore of the carb. I have poked a wire through that X & there seems to be a rubber gasket under it, my wire went through the gasket but I can't see light through it, could that be my problem? Maybe I shouldn't have poked a wire through it? Any other suggestions? . thanks. in anticipation.
Had the same problem with the neighbour's machine - was dirt on the needles - quick clean and away she went.
aj.2.,
Feb 8, 5:24am
Place your thumb over the air inlet, then pull the starter cord, this some times is a easy way to clean the jets without pulling the carb apart. It cerates more suction on the needles to pull stuff though. Often had to do it on a car that got water in the tank, from a rust hole. Took some finding as to how the water was getting in the tank.
skull,
Feb 8, 5:34am
Had that same fault with a no brand Chinese petrol hedgeclipper, asked the mower shop it came from about it and they said replace the carburettor, $20 or $25 it was. They said not worth keeping carb kits for them at that price. It was the diaphragm that pumps the gas through from the crankcase air pulses. I couldn't see anything wrong with it but fitting the one out of the new carb solved it. (I couldn't help myself, just had to find the fault) They said it was caused by not running the carb dry when not in use because of the shitty fuel we have compared to years ago when we had leaded fuel. True/false? I don't know but that's how it worked out for me, we run it dry when finished now, that was more than 12 months ago.
mechnificent,
Feb 8, 6:34am
Check the exhaust isn't blocked.
m16d,
Feb 8, 6:36am
Try a new plug. if that don't work then chuck the whole thing away.
skiff1,
Feb 8, 6:38am
Is the pick up in the tank clean?
johnn,
Feb 8, 8:56am
Thanks for all the suggestions (except throw the whole thing away:), nothing wrong with anything except that the fuel is not getting out of the carb & into the combustion chamber, this is proven by yhe fact that it will run if I put fuel down the carb.
jmma,
Feb 8, 9:30am
Did you put carb to inlet manifold gasket on right, line up the little hole (o:
gmphil,
Feb 8, 11:18am
didn't use gull e10 fuel ?
mechnificent,
Feb 8, 6:52pm
Put your thumb over the inlet and pull the starter and see if you have suction.
Then take your thumb off and pull the starter and see if there is air getting spat back out of the inlet. a small amount is normal, too much indicates a blocked exhaust or a faulty reed valve. When the spitting out was happening, did it have drops of fuel in it, if you put your hand bear it, does petrol get on your hand ? If it does, then the carb is mixing fuel, it's just not getting the air and fuel sucked into the cylinder.
johnn,
Feb 8, 7:17pm
There is suction, no drops of fuel get spat out, no fuel on my hand. So the carb is not mixing fuel. Reed valves look great. diaphram looks great. It is like everything is working but there is a blockage where the fuel exits the carb to be sucked into the chamber. In my original post I pointed to the X in the photo as I think the fuel should be going through there & up the plastic tube (which then has a needle coming from the other direction) but I have loosened, tightened, done everything I can & no fuel coming out of that tube yet it is not blocked, thus my reasoning about what is under that brass X thing (seems to be a rubber washer & I poked a hole through the centre of it)
mechnificent,
Feb 8, 7:30pm
That is one of the carby covers in that photo isn't it ? The fuel pump end cover. not the bady of the carby ?
In the carby body there is often a tiny steel frostplug covering the discharge hole, and under the plug there is often a small felt filter. That gets blocked. They can be thrown away. If you punch the plug in it's centre to concave it and reduce it's diameter a tiny bit it should bump out whith a bash on the bench, take the filter out or blow through the hole, then reshape the frost plug over a socket or tube and using a ball-bearing for a punch.
mechnificent,
Feb 8, 7:39pm
I just had a look at that second link. Different carby from what I thought but that plug with a hole in it looks like what I was describing. If it's right over the discharge hole in the venturi then it will be the felt washer/filter you poked a wire through.
johnn,
Feb 8, 7:56pm
Yes it is over the hole that goes to the tube (Venturi), that is what I wondered but didn't want to make a big hole in it. you have given me something to try. Thankyou. I will report back.
johnn,
Feb 8, 8:42pm
Hey mechnificent it now works, that X thing flew across the garage & I havn't been able to find it but now the fuel is getting in & the weedeater is running, Thanks for all the help I really appreciate it!
thefatfj,
Feb 8, 9:14pm
replace fuel filter in tank if it has one,
mechnificent,
Jun 28, 7:43pm
Ha. That's honest.
It will have been/had that felt filter I was talking about then. I've done the same thing and felt that same vague resistance and wondered if it was a rubber diaphram. The plug was probably only to hold the filter in.
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