High Quality Chainsaw Bars Husqvarna Toys

Almost dead 200T carburettor

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England
Are you sure the carb is bad
YESSSSSSSSSSSSSSSSSSSS!!!!!!!!!!!!!!!!!!!!!!!!!!

(Sorry to be melodramatic :risas3:)

I threw a working carb back on that 200T after retesting my "latest failed mend attempt". And yeah cut some more with that 200T since.

Seriously Steve, I've got some welch plugs on order, so taking that out and cleaning better is my next plan. Now I'm starting to service the neighbourhoods it would be real nice to get a couple spare carbs, and my OCD is "saying don't throw this one away till you've exhaustively all possibilities". And the last thing to do in my mind is pop out the welch plug.
 

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England
I dont see any in my carb collection they are all marked A.
Yeah. Thought so. Must be a Europe thing I guess. Thanks for looking though. TBH I don't think it's worth drilling through like tree monkey suggested, since it was obviously designed that way.

I'll have another play with it maybe next weekend when I've got the plugs etc. and post back then.
 
Last edited:

Lone Wolf

Pinnacle OPE Member
Local time
2:09 AM
User ID
887
Joined
Feb 14, 2016
Messages
2,042
Reaction score
4,481
Location
Nj
Country flag
Yeah. Thought so. Must be a Europe thing I guess. Thanks for looking though. TBH I don't it's worth drilling through like tree monkey suggested, since it was obviously designed that way.

I'll have another play with it maybe next weekend when I've got the plugs etc. and post back then.
This is why I keep a bunch of them in stock!
 

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England
Here we go O sceptics!

So I refitted the rough running C1Q-S126B carb, that is the carb from post #49 that has (from the factory) a BLANK impulse port. But firstly I loosened the top handle's screws and removed the impulse line from the bottom of the handle and plugged it with a bung.

Then with the carb dry, I successfully choked and started the saw. Since the carb is busted in some other way, I jacked the idle very high initially so that it would run. And here it is, this being the second cold start from dry...


And yes, I know it's running rough, and no that is not due the impulse not being plugged. It's got an existing issue I'm working on...But regardless it runs none the less, without the documented pumping mechanism in place.
 

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England
I already told you that. now drill the hole
That makes no sense to me Scott. I've just demonstrated in that youtube clip that it does not need that impulse port.

Furthermore, the clip I uploaded in post #59 shows that same carburettor running absolutely fine a few years back.

Therefore, in my opinion, something else is pumping the fuel.

My video surely demonstrates that the saw can suck up adequate fuel at idle and at WOT.

I'm sure that saw runs rough for another different fault, like I speculated earlier. The main issue I'm seeing is the transition from idle to WOT, when the throttle is blipped, which tells me there's either an L circuit issue, or an air leak - but since I've blocked up the acc pump circuit already, I strongly doubt that.
 

Wonkydonkey

Plastic member
Local time
6:09 AM
User ID
3189
Joined
May 14, 2017
Messages
4,564
Reaction score
18,073
Location
Sussex, UK.
Country flag
I was gonna reply last nite but I I lost track of time while looking at zama carb identifation numbers, I was also trying to find another saw that uses a 126/b model carb.


As treemonkey said drill the inpulse out and it don't work properly, you can always JB weld it backup, like the ac pump.
 

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England
I was gonna reply last nite but I I lost track of time while looking at zama carb identifation numbers, I was also trying to find another saw that uses a 126/b model carb.


As treemonkey said drill the inpulse out and it don't work properly, you can always JB weld it backup, like the ac pump.

Zama clearly designed it that way, since it ran fine for years like that.

Drilling it, I think, would be silly, since it obviously built like that with the port blocked.

If you do find another model with s126b tell me - because I want to order welch pump for it. And my 200T ipl only lists the parts for the S32 and S61 carbs.
 

Simondo

Here For The Long Haul!
Local time
6:09 AM
User ID
821
Joined
Feb 7, 2016
Messages
3,425
Reaction score
10,659
Location
UK
Zama clearly designed it that way, since it ran fine for years like that.

Drilling it, I think, would be silly, since it obviously built like that with the port blocked.

If you do find another model with s126b tell me - because I want to order welch pump for it. And my 200T ipl only lists the parts for the S32 and S61 carbs.
I think there was a possibility that the carb could deliver the correct running with the accelerator pump feed working properly as it will have put a measured charge of fuel through the main running nozzle when you snap open the throttle. Now maybe the impulse is more important.
 

Wonkydonkey

Plastic member
Local time
6:09 AM
User ID
3189
Joined
May 14, 2017
Messages
4,564
Reaction score
18,073
Location
Sussex, UK.
Country flag

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England
I think there was a possibility that the carb could deliver the correct running with the accelerator pump feed working properly as it will have put a measured charge of fuel through the main running nozzle when you snap open the throttle. Now maybe the impulse is more important.
Hmm..... I guess that's possible.

Well perhaps, after knocking out my welch plug, and cleaning the idle/low speed circuits as best as I can, if the thing still bogs on that transition I could try drilling the port through like Sean and Scott suggested. Nothing to lose really.

It's just annoying to have to have to drill through at an angle to do it properly. This seems like a requirement to carve out some kind of jig out of wood perhaps, to support the carb body correctly, while I drill through....
 

MattG

Chainosaurus Rex
Local time
6:09 AM
User ID
3111
Joined
Apr 30, 2017
Messages
896
Reaction score
1,432
Location
Cambridgeshire, England
The carb kits are a "one kit fits many carbs with a few bit left over"
Take this
https://www.ebay.co.uk/itm/ZAMA-RB-...282164018473?_trksid=p2385738.m4383.l4275.c10

Then google the part number it replaces/fits from the page, 1129-007-1062

This then gives you a link to
http://www.baileysonline.com/Chains...or-C1Q-Carburetors-Replaces-1129-007-1062.axd

And they list 126b in the spec as well a few others
Cheers Sean,

I ordered the chinese item (2.52) as a fall back but it's a bit of a wait to receive. Just wish I had the P/N for just the Welch plug in the S126B, then L&S could source me one in a couple of days.

i.e. the rounded rectangular one (a lot of the others are eggshaped) right here:


upload_2018-1-4_12-56-46.jpeg

do any of the other brit guys here, e.g. @Simondo , @jb-chainsaws know of the stihl p/n for this plug?
 

Simondo

Here For The Long Haul!
Local time
6:09 AM
User ID
821
Joined
Feb 7, 2016
Messages
3,425
Reaction score
10,659
Location
UK
Hmm..... I guess that's possible.

Well perhaps, after knocking out my welch plug, and cleaning the idle/low speed circuits as best as I can, if the thing still bogs on that transition I could try drilling the port through like Sean and Scott suggested. Nothing to lose really.

It's just annoying to have to have to drill through at an angle to do it properly. This seems like a requirement to carve out some kind of jig out of wood perhaps, to support the carb body correctly, while I drill through....
You have no "Datum" as you have changed a fundamental operation of the carb by blocking the accelerator pump off so it may be a good thing to see if the mod you have done has worked on carbs that "do have " a available impulse . Further.....Take note of the number of "transition "holes your blanked impulse carb has and see if there are more...... less or the same in a version with the impulse available. Also see if there is a cut out on the butterfly plate to give a air bleed ... then do a comparison to a carb with a available impulse. Remember to check out if that pressure causing vent has a bearing on the carb that saw would need ?
The ms 200 t had C1Q s32 with no pump..s61=pump...s96=pump ..126=pump and s127 pump i think (not seen one) These carbs are going to be in dif markets. The s32 is as likely as not the basic AM design without the pump.
Im no Stihl 200 specialist so its basic Diagnostic thinking on my part.
 
Last edited:

jb-chainsaws

Pinnacle OPE Member
Local time
6:09 AM
User ID
1846
Joined
Sep 12, 2016
Messages
730
Reaction score
1,904
Location
UK
Cheers Sean,

I ordered the chinese item (2.52) as a fall back but it's a bit of a wait to receive. Just wish I had the P/N for just the Welch plug in the S126B, then L&S could source me one in a couple of days.

i.e. the rounded rectangular one (a lot of the others are eggshaped) right here:


View attachment 104924

do any of the other brit guys here, e.g. @Simondo , @jb-chainsaws know of the stihl p/n for this plug?

They come in the Chinese carb kits sometimes, I may have a couple you can play with
 

Wonkydonkey

Plastic member
Local time
6:09 AM
User ID
3189
Joined
May 14, 2017
Messages
4,564
Reaction score
18,073
Location
Sussex, UK.
Country flag
I was thinking the same thing, but I had not looked yet !!. I know I've used a few carb kits and not done the Welch thing, it was one of those things,,where the fug are all those and what carbs did I fug with.
So was gonna find, measure, then say,,, I have a spare plug to fill your hole. ;)
 

tree monkey

Mastermind Approved!
Local time
1:09 AM
User ID
339
Joined
Dec 14, 2015
Messages
4,818
Reaction score
39,942
Location
wi
Country flag
your logic defies me
 
Top