McCulloch spark plug

[ipbr21054]

Since posting the video above I’ve got it going and running on its own for a good 2 minutes.
Choke on full & throttle held open.

Runs like this for as long as but as soon as I touch choke it does.

Touching the throttle also has the same affect.

So at present it runs but but won’t come off choke or able to throttle.

L screw out 1 turn

H screw out 3 turns

 

[Burnerman]

OK, if the machine runs on full choke then there is still a fuel starvation issue.
Presumably you have checked the fuel tank filter - although they rarely block.
Anyway, points to ponder:
1) The aluminium plate cover on the carb which is secured by only one screw - this must be air tight and its very difficult to check.
2) Lets come back to the carb needle valve (post#68, image 10). Presumably you removed this for cleaning? Anyway, on the other side of the pointed needle valve there is a very fine gauze filter, which must be clean.
John

 

[ipbr21054]

Plate with one screw where ???

Gauze replaced & cleaned.

Now off choke and also throttle off.

How do I now set L and H

The one screw you refer to is it at the top ?
If so this carb has two screws and I primer bulb

H now out 3 turns so now getting more fuel and choke off.

 

[Burnerman]

Apologies I forgot this carb has a primer bulb....that's the area which must be air tight but forget about my comment above.
The usual setting for the carb screws is 1 to 1 1/4 turns out each, from fully in....the fact that you are having some success with the H screw out more turns may be helping things but it won't accommodate a blockage.
Is a new carb on its way?
John

 

[ipbr21054]

It starts now i would say every pull.
H screw turned out 1/4 turn every time untill i knew it sounded ok at this point 3 turns.
Grabbed hold throttle & turned H screw CW until it altered then AC until altered & left it in the middle.

It now runs without the need to tape the throttle handle up but the L screw is wherever it is & need to adjust this now.

 

[Burnerman]

My post #82 may help......only adjust the L screw though!
If L is too far in (weak mixture) the engine may speed up a bit but is likely to stall when you want it to accellerate......Too far out (rich) the engine speed may reduce and still stall during accelleration, so its a bit of a lottery!
Hopefully you wont shift too far from the recommended setting of just over one full turn out.
John

 

[ipbr21054]

ok another job for tomorrow etc as tomorrow im out.

With regards the L screw.
At present i have the idle screw all the way in so the pointed tip is touching the metal plate if i now turn the L screw in will this have an affect as if not i was then going to start 1/4 out with it but if its going to affect it then i cant

 

[lostinthelight]

Just something to add to this.
In one of my first posts i added this photo.
View attachment 168543

I mentioned that the top green arrowed pipe enters the tank & has a filter on it.

The white arrowed hose enters the tank & thats it.

Ive put mine back the other way around so now im doubting myself ???
With some fuel in the carb & both hoses off when i press the primer bulb i get fuel coming out of the top metal pipe.
This is why i thought it was a return

Sorry, I threw you bum info on this and the way you now have them is correct.
I based my reply by quickly looking at a machine I had in for repair which now Ive come to work on it , amongst other faults it has the pipes the wrong way round,

 

[ipbr21054]

Thanks,
As i bought it for £10 non runner it was cheap but i couldny beleive anything the previous owner had told me.
Not because of being a liar but needed to satrt from fresh & just because he put a gasket on one way didnt mean it was correct.

Anyway new plug, plug cap, spark plug, air filter, carb kit now worth it.
In all with the cost of the trimmer its cost say £22

 

[Burnerman]

Theoretically having the L screw fully in should blank off any idling fuel, but in reality discrepancies / wear in the needle overcomes this.....over tightening the screw can damage the needle seat too. Open it one turn to give the machine a chance!
Hopefully you've enjoyed the experience - you need to be psychic at times, but after a while engines 'talk' to you......corny I know but true!
John