Petro Flymo Strimmer

[Pengwyn]

Hi guys.
I have a petrol flymo strimmer. Which has been great for a couple of years. The pull cord snapped so I've replaced that and after fiddling with the spring for a while I got that sorted.
The problem now is that when started it races at full revs until it is screaming and then it stalls. It will start again with the same results.
This has been sitting in the garage for a while.
I have stripped the obvious bits and pieces with obvious joy.

Any advice would be greatly appreciated.

 

[Mursal]

If you take off the air filter you should see the accelerator (throttle) butterfly in the carburetor? When you trigger the accelerator it should open and then close when you take your finger off? I would think its stuck open, sometimes the handle moves in relation to the engine and pulls on the cable, holding the accelerator flat out.

Or if its a really really old one, it might have an air flap that works on the air from the flywheel,to control the engine speed. You may have disturbed this flap or linkage from it to the carburetor. As the pull cord works off the same flywheel.

Yes, that spring is a nightmare

See how you go

 

[Pengwyn]

Thanks for the reply. I have checked the accelerator flap and it is free.

Any other ideas.

 

[Mursal]

Can you keep it running by triggering the throttle and or choke?

You could try kinking (blocking) the fuel line into the carb, and run it dry. The fuel may be leaking in when stopped. If so, you need to clean the carb out, as the needle has stuck open.

Were you "playing" with the carb setting screws on the side? If so just tighten both and let them out 1 full turn. If you have not touched them, just leave them alone

 

[Burnerman]

I would suspect that either the throttle cable has become snagged somehow, or the tickover screw has been turned in accidentally.....does the throttle trigger just feel like it did before?
John

 

[Pengwyn]

Trigger throttle is not stuck.
Tick over screw is fully backed off.
There is a joint/diaphragm.
Could this be the cause?

 

[Burnerman]

The carb has two flat diaphragms, a pump one and a metering one.
Any two stroke will tend to rev a bit if there's an air leak, but I can't see how its possible to cause this if all you've done is replace the starter cord....have you had the carb apart?
John

 

[Pengwyn]

When I replaced the cord and got it going it rev'd very high so I stripped the carb down. Ill do it again and check the diaphragms for holes.