Stihl 020 buggerage

[Joe Newton]

1 hour ago, spudulike said:

It was a very valid suggestion and may well be correct!

 

Serves you right for poncifying a carb boot into a "manifold"!

[spudulike]

10 hours ago, Joe Newton said:

Serves you right for poncifying a carb boot into a "manifold"!

Sorry Josephine, I will be less eloquent in future and call parts "doofas", "thingies" and "whotsits" just for you

[Treerover]

Probably a big ol air leak. Normal suspects are impulse line or the intake manifold........but what do I know:001_tongue:

Right then, I've taken the intake rubber dooby manifold off and closely inspected it (its only about a year old) and its ok, I did find a tiny hole on the impulse line only visible when pressured with air under water !! and it was slightly kinked through the exit hole in the body. Ive cut out leak at the end and enlarged slightly the hole in the body to give it a smoother run.
It STILL won't idle though.
I've swapped carbs, swapped diaphrams, swapped plugs, mixed new fuel but no, she won't have it.
Fires up lovely, runs at full tilt beautiful but as soon as the throttle is let go it dies. Will fire up straight away again on choke and then run whilst throttling but then dies as before. The idle screw is wound right in
I'm officially at the 'garden tossing' stage and I don't mean in the liberated naked neighbourly offensive way [emoji35] [emoji17]

Any more thoughts anyone ??

[Ratman]

I’d still question the impulse line, why has the hole appeared in the first place? Could be perished further still, and not noticed to the naked eye. For the cost of a new one i’d defo try that first.

[Ratman]

Have you fit a complete new carb kit or just the diaphragm?

[Treerover]

I’d still question the impulse line, why has the hole appeared in the first place? Could be perished further still, and not noticed to the naked eye. For the cost of a new one i’d defo try that first.

I see your point but I pressure tested it with a syringe and forcep clamped the end (you wouldn't think my better half was a nurse would you!!!) and so I'm pretty confident any further leaks would have shown but yes I think a new pipe would rule out another component in the conundrum.

[Treerover]

Have you fit a complete new carb kit or just the diaphragm?

Thing is its the same with 2 x different carbs, 1 x new chinese one and the old one. Yes i've replaced all the bits in the carb kit apart from those impossibly difficult silver blanking plate fingies .
I weep salty tears

[Ratman]

[emoji23][emoji23][emoji23] the chinese carb could still be “iffy” even though its new. Have you set the metering arm lever up properly? Have you defo, refit the diaphragm etc in the correct order?

[spudulike]

Those Chinese carbs are a bit suspect, they have left off the small cut out in the throttle valve and it cocks up the low speed carb setting.

The original carb has probably got issue as why else would you buy a Chinese one?

So - either try your bevvy of carbs out on a known good saw or try a carb from a known good saw on your one.

The other things that would be worth checking - muffler off and inspect the piston through the exhaust port. If this is a bit technical then get the saw hot and do a compression check.

The other is to get an old plug, bend the end electrode away from the centre one and test the spark by pulling the saw over with a slower than starting pull and you should get a good cracking spark of the plug when connected and grounded on the muffler or cylinder.

I am baffled as to why I get so many 200s in and then again.....perhaps I am not

[Treerover]

Those Chinese carbs are a bit suspect, they have left off the small cut out in the throttle valve and it cocks up the low speed carb setting.
The original carb has probably got issue as why else would you buy a Chinese one?
So - either try your bevvy of carbs out on a known good saw or try a carb from a known good saw on your one.
The other things that would be worth checking - muffler off and inspect the piston through the exhaust port. If this is a bit technical then get the saw hot and do a compression check.
The other is to get an old plug, bend the end electrode away from the centre one and test the spark by pulling the saw over with a slower than starting pull and you should get a good cracking spark of the plug when connected and grounded on the muffler or cylinder.
I am baffled as to why I get so many 200s in and then again.....perhaps I am not[emoji6]

I'm attacking from all angles Spudders aren't I !!!!!
Borrowed my mates carb and all good, saw runs lovely with his genuine Stihl carb.
So burning question........where to get a reasonably priced carb?? Are Walbro an option for the MS200/020 ?
I think I shall not be bothering with any pattern chinese parts I don't think from now on . I have had too many cheap far Eastern tools/parts let me down just recently.