Which screw to allow more fuel for petrol strimmer advice

[ipbr21054]

I swapped the whole throttle trigger assembly from one strimmer to another of the same make / model etc.
This also consisted of the wires going to coil & also throttle cable still connected to carb.

The strimmer it was removed from run perfect but pull cord snapped & somebody had rounded off the T25 screw that holds that clutch drum on of which i was unable to remove as its down inside a small metal tube.

The strimmer that it was fitted to also run very well in respect of sound it made when strimming.
Using it today it seems to be struggling somewhat by the sounds of it.

Using the choke lever a little you could hear it run much better.

So i assume setting up a carb for each engine is different so i assume it needs to be altered slightly for the spare.

Two photos supplied but not sure which screw i need to touch to make a slight improvement, BLUE arrow or RED arrow ?
Second photo just shows the top one better.

Thanks

 

[Burnerman]

The screw indicated by the blue arrow is actually a tapered needle that fits into the main jet......personally I've never had to adjust one of these so I'd go for the other one, and unscrew it anticlockwise an eighth of a turn at a time.
John

 

[ipbr21054]

Will give it a go thanks.

 

[jj4091]

If you don't have any joy with adjusting screws then it may have a centrifugal govenor in the crank case which might have failed. These givce similar problems.

 

[foxhole]

The screw sticking out not marked may be idle screw .

 

[ipbr21054]

The issue let’s say is more of a fuel starvation as opposed to its tickover.

Will look tomorrow thanks.

 

[Burnerman]

The idle screw is visible in the first pic.
Count how many turns the brass screw has before removing it completely.
The carb may benefit from a good clean out, of course!
John

 

[ipbr21054]

This carb was running fantastic on my strimmer. Once home I took it off & put it on my other strimmer.
Cleaning isn’t the answer.

 

[Burnerman]

How about the fuel supply.......fuel, tank filter etc?
John