2 Stroke Strimmer Engine

[canedmonkey]

Hello,

I bought this strimmer second hand off ebay last year. When I picked it up, the bloke got me to start it to show me that it worked and it started first time. I then started it again when I got home, refuelled it and then used it twice on our allotment with no problem.

http://www.einhelltools.co.uk/product-list.php?pg1-cid2044.html

Since then it will no longer start. At first it would take a real effort to get going, it would start but then stall immediately especially if you closed the choke. I found that if I got it started and grabbed the throttle straight away I could keep it going but it sounded very loud and would stall again if the throttle was released.

I've tested and replaced the spark plug, that works and the air filter is clear.

So, on the assumption that it was the fuel supply, I tried readjusting the carburettor but no joy. I then took the carburettor off, dismantled it and found that a small rubber bung that sat above the primer bulb had perished and fallen off. Thinking that I had found the problem, I bought a new primer bulb (it came with the bung) and before putting the carburettor back together, I spray cleaned it and made sure nothing was blocked.

http://www.einhelltools.co.uk/product-info.php?pid37021.html (Primer Bulb, the bung I’m talking about is the red ring in the picture)
http://www.einhelltools.co.uk/product-info.php?pid42589.html (Carburettor, FYI)

Now that the strimmer is back together, it still wont start. It may be that the carburettor is not set properly but I've long lost the original position and as I can’t start it, I've no idea how to adjust it.

Any ideas please?

 

[Burnerman]

Just a wee bit confusion here.....the picture of the primer bulb is for a remote one (not fixed to the top of the carb) and yet the carb pic shows a primer on top - it's not necessary to have both!
If the carb pic is the actual item, that primer bulb should be full of fuel before the thing will start.
John

 

[canedmonkey]

The primer bulb is a part for multiple machines so for mine you need to remove that black plastic cover before fitting. The primer bulb is on the bottom of the carburetor not the top.

You say that the bulb should be full of fuel before starting but I notice mine is about half full... Could that be the problem?

 

[Burnerman]

I see .....it's just the bulb alone you need - the bit you press with your thumb?
That's sorted that one!
When you press the priming bulb, it should pump fuel up from the tank to the carb - so long as there is fuel visible, that's fine.
Ok, here's what you do to start these pesky two strokes !
Prime the bulb - usually 5 presses or so.
Full choke, full throttle, pull the starter cord very briskly.....show it who's boss!
The engine should fire (pop) after 3 or 4 pulls. When it does, choke off, keep throttle open full and it should start within 2or 3 pulls.
If no joy, post back.....but you may have 2 screws sticking out of the carb, marked L and H? These are Low and High fuel mixture screws......from fully in, give them one full turn out each to begin with.
John

 

[canedmonkey]

Thanks John but I've already tried starting it dozens of times with no joy. As you say, there should be two screws on the carb one for full and one for idle but this carb only has one so I'm not sure which it is for.

I tried closing the screw, tried to start, then gave it half a turn, tried to start again but nothing. i did this until the screw was as far out as it would go but then fuel started to leak out of it so I obviously went too far. No setting in between seems to remedy the problem so I'm at a loss as to what to do next.

 

[Burnerman]

Ok, there's a good chance that the engine is full of fuel......so whip the plug out, turn the engine upside down (or so the plug hole is at the bottom) and crank it over a good few times.
There's a good chance that raw fuel will spray out of the plug 'ole.
If there is, it shows fuel is getting there but if it's absolutely dry then there's still a carb fault.
These carbs are very delicate inside - personally I won't try to clean them unless I have an aerosol can of carb cleaner and preferably a supply of compressed air. How did you do yours?
John

 

[canedmonkey]

I cleaned it with STP Carb Spray and I was ultra careful with all the gaskets and made sure everything went back as it should. I spayed the cleaner into all the holes and made sure it came out the other end so there were no obvious blockages.

I'll have a look for the plug on the engine block, I haven’t noticed one before but this is probably because the engine has a plastic cover so it will be under there.

This will be a weekend job so I'll report back on the results.

If anyone else has any suggestions please feel free to chip in.

 

[Burnerman]

Sorry, naff explanation from me...it's the spark plug I'm on about....remove it, invert the engine and pull it over. This will remove any raw fuel from the crankcase.
John

 

[canedmonkey]

Ah that makes more sense, I'll give a go and let you know.