Stihl MS200 Carburettor

[NorfolknGood]

Having trouble with my MS200, it wouldn't rev unless I held a bit of choke in regardless of how the carb was set (originally 3/4 on top end and 1 turn on L). I had the carb apart the other week and blew it all out and after it ran sweet as but today I goes to it and it wont rev. I clean carb again same as before and no different. So I thinx possible air leak on manifold? so I strip it all down and check but it's fine. Clean carb once again but.............. A round ended rectangle of ali falls out and when i put it back it's just free floating, nothing to hold it there.

I try starting it again and this time it's over fuelling so I guess that piece of ali should be in with a sealant or something?

 

HELP!!!! I guess I have done something wrong in my ignorance! I have never come across anything like it as I have only really had Walbros apart from my large modelling days.

[mixedangased]

thats a sealed core plug,normally pressed sealed.you might be lucky and reseal with a punch

[Scott Walker]

Id also go with a new carb kit! As you can see the old gaskets started breaking down.

 

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[Ray1]

Careful with that screwdriver resting on that metering arm. You can seal the plug in with nail varnish.

[NorfolknGood]

Thanks you gents, the screwdriver is just a pointer, a little JB weld will do then for that core plug

 

and a C1 kit from Ebay: http://www.ebay.co.uk/itm/Stihl-192T-020T-MS-200-T-ZAMA-C1-Carburettor-Diaphragm-Kit-/201094209570?pt=UK_Hand_Tools_Equipment&hash=item2ed2262022

[spudulike]

That is the welch plug, they are sealed in by punching only now as the ethanol in the fuel started dissolving the adhesives that were being used to seal them in.

 

All the aforementioned adhesives will deteriorated when fully submerged in fuel - it may say on the tin that they wont' but I have been there and done that. The only stuff that will work is SEALALL or you MAY get away with a very thin smear of superglue and some work.

 

The welch plug MUST be sealed in 100%, leakage will cause a very poor uneven idle. Make sure no adhesive gets in or on to the low speed jet holes:thumbdown:

[Dean Lofthouse]

Here's one I've been having problems with....carb that is. The saw hasn't been running well with bad acceleration and lack of fuel symptoms.

 

This is similar to the carb above where a plate seals a port or hole (welch plug ?). I don't know whether the problem is the sealer pealing causing air leak or the sealer going under the metering lever.

[Dean Lofthouse]

another closer

[spudulike]

It is typical for the residue of sealer to come off around the Welch plug (much bigger on the 020 carb) but they seem to seal better than the MS200 one.

 

If the seal is bad, the idle will wander all over the shop and not dial in as it should and in some cases will soar and then just die.

 

If the pick up is poor, it could be the check valve is a bit dodgy, this can cause mid to high rev issues. A good clean can help but have known these 020 carbs just need replacing if very old and put it down to wear in the throttle valve shaft etc.

[NorfolknGood]

I resealed mine with super glue. 1st sat the plate in place then put a drop of glue on a piece of wood, dipped a pin in it and wicked it in to the joint.