STHIL KM55 Strimmer, fuel problems

[RCD_70]

Hi, got myself a Sthil KM55 strimmer, only problem is it doesn't start 🤣, anyway it doesn't pull fuel into the primer bulb, cleaned the carb out, changed fuel filter no joy so took the plunge and bought a carb from ebay. Fitted, primed and fired up....for around 10 seconds, then primer bulb was empty, it cut out and now exactly the same as the original carb and won't prime hence won't start.
Changed fuel filter, pipes, carb, plug, air filter. I've seen one or two videos on YouTube but none really to do with this problem. Any ideas as fast losing the will with it. Only bought it as everybody I know uses sthil.
Cheers Rich..

[Mick]

So it's not priming any more?

[Mick]

While it's not uncommon for those carbs to stop priming, it's strange that both carbs are playing up,

I'm wondering if the gasket between carb and intake is located incorrectly, or the pulse hole in the gasket isn't lining up with the pulse hole on the carb. This would prevent the fuel pump from working. 

[RCD_70]

While it's not uncommon for those carbs to stop priming, it's strange that both carbs are playing up,

I'm wondering if the gasket between carb and intake is located incorrectly, or the pulse hole in the gasket isn't lining up with the pulse hole on the carb. This would prevent the fuel pump from working. 

thanks Mick, I've sorted the starting and priming finally, there was that much crud in the tank there's no way it was going to run, cleaned tank & carb and filter and away it went..only thing is now I needed to change pull start cord as was threadbare and spring has let go under the pull start wheel, the pin had come adrift and as soon as I took the casing off I heard it! Any tips for winding it back into a fairly deep casing? Thanks Rich..

[Mick]

Glad you're making progress. 

The spring I would wind up in my hand and grab it and drop it in with a pair of long nose pliers.  Or if you've ever had a new spring it comes in a plastic holder which doubles as a insertion tool.  You can wind the spring into that and drop it in.

Just make sure when you wind the spring up you back it off a couple of turns, otherwise you risk pulling the end off the spring.