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carb repair for the ms 200T

Al Smith

Mac Daddy
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Mar 6, 2005
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It's not the amount of air available on the atmospheric side of the carb but rather the area of the intake channel.Theoretically say for simplicity sake of explaination say you had a 1" venturi connected to a half inch intake tunnel .It would only pass 1/4 of the amount of air were it a full 1 inch .Now that's an exageration but the point still remains .The only way you could get any more air through a smaller tube is by forced induction ,blower .You're dealing with atmospheric pressure .

Then enters into the mix the needle valve .That thing is only regulating the fixed jet in the carb .It's the pressure drop over the fixed jet and the size of it that determines the amount of fuel it will suck .That plus the fact that being a pulse carb it acts somewhat like a mechanical fuel injecter with the positive and negative pumping action of the diaphragm .

I don't know if this will work or not in this application .Often times a "ram tube " basically a funnel connected to the air intake of the carb can increase the air flow .It actually acts like a funnel but has no effect unless the engine is running at speed . They used them on go karts ,hot two cycle bikes ,snowmobiles and I have one on a 2100 Husqvarna .Still in all what effect that would have on an undersized intake I have not a clue .Might not do a thing .
 

Al Smith

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Let me give an example I'm familiar with .C4 Fun once had a hopped up 166 Sachs alkie burner with the largest carb of any saw I'd ever seen .If you opened the butterfly and looked though it it was looking down a hole clear to the piston big enough to drop a golf ball though .The intake had been modified by some means to match the venturi size .

It moved so much fuel that when you hit the kill switch you had to tip the front of the engine and let the excess run out of the carb because just the last few revoutions of the engine with no ignition would flood the saw .Had that intake not been matched to the huge increase of the carb size it most likely wouldn't have even been possible to start .
 

Al Smith

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More,rambling on .Since I'm intrigued with this thing I did a little research on Tillotsons site specifically the model HS .I have no idea what carb it actually is but an HS is pretty common .

Under the trouble shooting section it mentions the fact that possibley a welch plug could be leaking thus causing the needle valve to have little effect or not total control of the high speed jet .Red Loctite maybe ?
 

woodworkingboy

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Aug 16, 2008
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Nippon
A leaking plug could be a possibility. I put on a used carb that I had no previous experience with. Thanks.
 

Al Smith

Mac Daddy
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Well I did seal that carb and it did start and run okay or so I thought .

So today I was at c 4 Funs and we were going to do timed cuts testing a standard Stihl semi chisel in comparrison to the new full chisel they came out with .That little rascal made one cut then on a restart fell dead on it's butt .No amount of richening the carb made any difference .I had originally thought heat made the carb expand and open the crack but not a 7 second run .It may be a crank seal .Oh the plot thickens .
 

cory

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i missed this thread before. There are very few things that are better than a meticulous, experienced mechanic! Awesome presentation.
 

top_notch

Treehouser
Joined
Feb 9, 2008
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Steamboat Springs, CO
Did the repair tonight and made about ten cuts...enough to warm the saw up, and it ran SWEET!!! Hope this fix is permanent, will see in the next few days when I have some jobs to do down here in FL. Thanks again Marc!8)
So far, the saw has been great. I think its fixed, but hopefully I don't jinx my self.
 

Al Smith

Mac Daddy
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As I said neither of my two 200's have that praticular carb with the accel pump .I'm not certain if the one I sent to Edie at Stihl did or not .

If I have time tommorrow I'll run the super bee to see if my fix on the bearings/seals fixed the problem .If not I'll change the carb out from the stock 200 to verify .The stocker runs fine so I know the carb is okay on that one plus it had almost no side play in the crankshaft .
 

Cut4fun

Redneck Chainsaw Repair
Joined
Nov 27, 2007
Messages
2,648
Larry a saw collector here in Ohio and owns HOS - House of Saws and works for stihl dealer has this info about a replacement for 200T carbs WITHOUT the acc pump.

chainsaw-57 said:
200 T Carburetor

Hey Guys, Try 1129 120 0650.

Fully adjustable, non-EPA, no accelerator pump.

Much less expensive, probably will not notice lack of pump.
 

CurSedVoyce

California Hillbilly
Joined
Jun 30, 2008
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Near Yosemite in CA USA
Larry a saw collector here in Ohio and owns HOS - House of Saws and works for stihl dealer has this info about a replacement for 200T carbs WITHOUT the acc pump.
Just a heads up on this carb 1129 120 0650
I ordered one from my dealer last week and got my 200T back up and running. I was told they will no longer be available after December 2014.
 

timmy

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Jan 23, 2015
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Hello, i'm new to this site but have been repairing stihl machines since 1992 on and off. I was given a ms200t to fix and was told by my carb supplier that its a Stihl part only ! After finding out they where going to charge my £102 I thought i'd look into it on the web. Until seeing this site and this thread, i was coming up with nothing much that could help. Even though i can't see the photos, i've fix the carb as suggested and "IT WORKS" .
I have noticed that there is a slight hesitation on pick up but once warmed up it seams to run fine. Tomorrow i'll try it out on and "OAK" and see how it runs.
I can only say a very big thank you to you all for such excellent advice :)
 

timmy

TreeHouser
Joined
Jan 23, 2015
Messages
2
Hello and thank you for the welcome.
Well i tried out my ms200t and after running fine last night it wouldn't start this morning :X Then i realised i'd only put a small amount of petrol in, oop's. ( I don't like filling up things just incase they catch light in the work shop !)
So after filling it up, it ran fine cutting small oak limbs with out any problems.
So once again i thank you all for this post and all the information given :)
 

rskybiz

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Aug 26, 2010
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Fort White Florida
Another this place rocks statement right there!

All things heavenly rarify to air. Trèès pŕoduce that heavenly air. Breathe air and take care.
 

Marc-Antoine

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Apr 17, 2011
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France
Imageshake trashed a huge amount of pics, mostly in the 2 years old range and before. A lot of threads are useless now on the french arborist's site. I saw the ask from Magnus about the pics, but I wasn't at home and can't answer. The internet is really bad for months in my town, slow rate or / and unstable connection, and the download and upload is a pain. So I hesitate to try sending new pics, because I'm sure I'll get a transmission failure.

I'm glad that Magnus sorted it out without me.:)
 

Magnus

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May 6, 2005
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South East Sweden
I have done this many times on 200's now and had a custemer with a 192C that had same issues.
I removed accellerator pump piston and spring. filled rear end of piston and its seat with epoxy, put piston back (no spring). And after epoxy was hardened I ran it and I think it ran better than new.
He replaced carb 2 times, piston seal two times.
Now it will last as long as rest of saw.
 

Al Smith

Mac Daddy
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Mar 6, 2005
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Northern Ohio
The thread goes back a lot longer than I thought it had .If I didn't say it before I had sent one carb to Eddie Anderson who at the time worked at Stihl Va Beach .They ran it through the carb lab and found internal leaks but could not determine exactly where it was .Eddie sent new a new carb with a pump which I never retuned and the little hot rod had never ran that good and I've never retuned it it from factory settings .The irony in this I haven't used the damned little saw in over three years and the damned thing is being an a-hole and won't start .Another on the to-do list . --it's always something . :(
 

treesmith

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Feb 4, 2009
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Alabama
I get about a year of daily use out of a 200T before needing a new carb. Still carbs run $80-ish while the China carbs on eBay run about $14-15, and they last a year too.....
 
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