McCulloch petrol strimmer

[Burnerman]

Just looking at picture 3 from your post #5......I can see the original welch plug before you removed it.
In post #13 I see the plug after you removed it - did you use a scriber or simiar as it looks damaged? Either way, these plugs can only be used once.
They are available:
https://www.gardenhirespares.co.uk/...-b-c1q-s34-a-to-b-carburettor-repair-kit.html

When carburettors like these are used on racing kart engines, the welch pugs may be removed, but the engine will only run flat out, and no low speed or idle.
John

 

[dstill]

Hi John, yes, I have to prise it out. There was a new one in the rebuild kit which I put back in but its loose, guess I was too afraid to press too hard but I will try with a bit more pressure.

The other Welsh plug in the photo came in the kit but I cant see one in my carb, do you think its just there for some other deriviations of the carb I have?

 

[Burnerman]

Ah, I see. Yes, use a small punch to flatten the plug out and it should be fine, and yes again to the spare plug that suits other carburettors.
John

 

[dstill]

Thanks again John, I will do that and let you know how I get on.

Thanks, Dave

 

[dstill]

John, just before I try, its dome side up and do I need to press it in so it ends up flat or just press it in enough so it stays in place?

 

[dstill]

Hi John,

I managed to secure the welsh plug and I also found some gel like substance in one of the filters which I assume was old fuel. Cleaned this out and its running like a dream, thanks for all your help, it is hugely appreciated.

Best regards

 

[Burnerman]

Many thanks for the update, and delighted you've sorted it!
Just as a post script, the gunge you found would be old fuel which turns waxy....if you don't use the machine often you can buy Aspen fuel - either two or four stroke is available- which is good for years (at a price though )
Stay safe
John

 

[dstill]

Well guys, it seems like a traditiin for my strimmer breaking down on an annual basis!

I cannot get it to start, it tuns over fine but won't start uess I put a small amount of fuel directly in the cylinder, but then just runs for 10 seconds and stops again. I've noticed when I try to start it fresh feel seems to be spurting out of the exhaust.

Just to give some context, it had a new diaphragm kit last year and I've replaced the spark plug last week

 

[Burnerman]

Best to clear the cylinder by removing the plug and cranking it over a good few times.
Before trying to start, is the primer bulb getting full of fuel?
Do check the fuel pipes to and fro the fuel tank, they often degrade especially with E10 fuel
If the engine starts then starts to fail, just try catching it on the choke or maybe giving the primer a little press.
John

 

[dstill]

Hi John, thanks for the advice. I forgot to mention that I replaced the fuel pipes and primer bulb about 6 months ago.

The primer bulb doesn't get full of fuel like it used to to be honest, but there is some fuel in it when I prime it.

 

[Burnerman]

The primer bulb doesn’t have to be full but you should see fuel returning to the tank if all is well there.
Theoretically you can’t over prime these things, unless the needle valve inside the carb is faulty.
John

 

[dstill]

Yer, fuel is returning back to the tank when I prime it, still won't run though.

 

[Burnerman]

If you think the machine could be flooded, keep the throttle wide open and then spin the engine over without using choke - if it still won’t cooperate, then apply full choke and try again.
If the machine even just fires once, knock the choke off, keep full throttle and try once more.
John

 

[dstill]

If you think the machine could be flooded, keep the throttle wide open and then spin the engine over without using choke - if it still won’t cooperate, then apply full choke and try again.
If the machine even just fires once, knock the choke off, keep full throttle and try once more.
John

I got around to trying this and it's just not having it, i think I've exhausted everything now and need to admit defeat.

 

[Burnerman]

Lets go back to basics before you burn it
Does the engine seem to have plenty of compression.....so when you crank it over does it go pop pop pop?
If that seems ok, have a search for a replacement carburettor - amazon / ebay can come up with some gems.
Post a pic of the carb if you like.
John