200T Carbitooter Thread **Official**

Grande Dog said:

Howdy,
I see they've had 14 different carbs for that saw. All of them are proprietary to Stihl from Zama. It is possible that another C1Q carb would work if you switch out parts. It could be simple as just a different choke or throttle shaft. Might be able to be figured out with IPL and part number and paper chase it. More than likely you would have to get the players in front of you to see what needs to go where. If you want too see the Zama options, enter C1Q@ in the search box on our website and it will pull them up.
Regards
Gregg

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pgg said:

Brand new carb is the easiest, but you can whip out the throttle shaft to access the accel-pump and decide what to do with it, either replace the tiny O-ring on the tiny piston or just ditch the piston and spring and epoxy the stupid accel-pump hole shut. On the accel-pump Zama there's a welch plug at the back of the carb that accesses the accel-pump circuit, lets you plug the pump circuit without having to remove throttle shaft, pump and spring. The accel-pump passage runs thru to the main nozzle and if the pump is dodgy and not sealing, air gets sucked direct to the main nozzle and leans the fuel supply all to hell

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Lakeside53 said:

If it's not the usual stuff.. generally no. Zama had a QC problem.. The accelerator pump galls the carb body. The C1Q61,61A, B and C fail. The D seems to be holding in somewhat ok, and the 61E is latest.

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Lakeside53 said:

The carb is Stihl only. Zama makes them specifically for the MS200T and for Stihl, not the general market. You can try replacing the pump -a kit is available, but you need to know exactly what carb you have.. and I wouldn't bother kitting anything prior to an S61D

The S126 works great. The non-accelerator pump version is the older C1QS32 - still available from stihl. Lacks the initial "punch" of the later versions, but very reliable.

BTW.. 140 isn't great on a 200T... rings... piston...

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Lakeside53 said:

BTW.. taking out the accel pump requres removing the butterfly from the throttle shaft. Often the brass screw will either strip or the head will gall. When you put it back, after geting the throttle plate in the exact postion, tighten, then peen (use a suitable anvil!)the far end to stop it from coming loose, and use loctite.

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Lakeside53 said:

The S32 is a butt-simple carb.. none of the problems of the S61. Just rebuild it if you're concerned.

Squirt some carb cleaner at your base gasket. If it changes idle, then it's leaking. You shouldn't reuse gaskets, but if you do put on a thin smear of gasket sealer.

Seal failure is rare on the 200t... and as you'll notice, they are not "ordinary" seals - they have a skirt instead of a lip, and must be installed the correct way around.

How was the piston skirt wear? No mill marks means worn... and a worn skirt will give idle instability on the 200T.

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Lakeside53 said:

They are dead easy to work on on after you've done a few dozen:greenchainsaw:


Side play isn't great, but for small amounts I've stopped replacing bearings in these... seems to have little to no effect on running. End play is normally 0.5mm, but can be more...

You can buy an accelerator pump kit, BUT, the failure is usually the worn body. A new kit will last long enough to sell it on ebay, but..

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pgg said:

For a pretty well used 200t, just new rings and seals and you're good to go, well worn in bearings let the saw rev out easy, also a 200T does rev higher than an 020T. The tiny 200t bakelite seals are difficult to tap in, brittle as, the metal ones are way easier, on the dodgy carb, I'd go for the accel-pump kit if they are available, it'll be just a spring, o-ring and rod, you slide out the throttle shaft, a non accel-pump carb better though. You can tell accel-pump carbs by the hole over the throttle shaft

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Lakeside53 said:

Ax-man said:

The C1QS32 020T two screw non-accel carb is still available, and works well on the MS200T

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lakeside53 said:

i have replaced very few 200t/20t pistons in 5 years... And these were on on very high time saws. They don't sell for $200... Try $90.50. They wear out very gracefully - get highly polished and very worn rings, but that's at a few thousand hours. The cylinders rarely score. We service hundreds of these per year.

Scaring? Can you post a pic? Is it on the exhaust side or the inlet. What was the compression? At about 130-135lb ("yellow" ), the 200t is dog. I've seen a few like this... But they keep on using them or sell them to homeowners.

The most common problem on a 200t is the carb. Until recently, the life of the accelerator pump was about 2 years (a zillion trigger pulls). After that, boot torn, impulse hose off... Seals - very rare.

For a 200t not to idle because of the piston, the piston would be clattering around - really loud. Did it suddenly "not idle" or did you have to "goose it" for the past xxxx months (bad!) to get to to accelarate? If the latter, acellerator pump, and you've been lean in transition.


I have seen scratches on the exhaust side due to carbon build up in the exhaust port -that's because some of these saws spend a lot of time hanging on belts idling. It had little effect on the running though and didn't affect idle.


Did you lean out the saw? I get 200's in all the time that have been leaned out to about 15,500-16,550 rpm.. That's going to take a toll.. I reset them to 14,500...

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lakeside53 said:

i have replaced very few 200t/20t pistons in 5 years... And these were on on very high time saws. They don't sell for $200... Try $90.50. They wear out very gracefully - get highly polished and very worn rings, but that's at a few thousand hours. The cylinders rarely score. We service hundreds of these per year.

Scaring? Can you post a pic? Is it on the exhaust side or the inlet. What was the compression? At about 130-135lb ("yellow" ), the 200t is dog. I've seen a few like this... But they keep on using them or sell them to homeowners.

The most common problem on a 200t is the carb. Until recently, the life of the accelerator pump was about 2 years (a zillion trigger pulls). After that, boot torn, impulse hose off... Seals - very rare.

For a 200t not to idle because of the piston, the piston would be clattering around - really loud. Did it suddenly "not idle" or did you have to "goose it" for the past xxxx months (bad!) to get to to accelarate? If the latter, acellerator pump, and you've been lean in transition.


I have seen scratches on the exhaust side due to carbon build up in the exhaust port -that's because some of these saws spend a lot of time hanging on belts idling. It had little effect on the running though and didn't affect idle.


Did you lean out the saw? I get 200's in all the time that have been leaned out to about 15,500-16,550 rpm.. That's going to take a toll.. I reset them to 14,500...

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pgg said:

Par, the pump is just a simple brass plug(piston) with an O-ring on it and a little coil spring under it sitting in a hole(cylinder), the piston gets pushed in when the throttle shaft rides on it when you touch the throttle, springs back when the throttle shaft turns further around, it just squirts a bit of gas just off idle only. It's little cylinder has a passage connected to the fuel bowl and the exit has a passage to the fuel nozzle. Slide the throttle shaft out and you'll see the little piston sitting in it's hole, it'll actually spring out when you slide the throttle shaft out. I've heard that there's a repair kit to fix the leaky pump, I'm guessing the repair kit is a new piston, O-ring and spring, but I reckon it's just the tiny rubber O-ring that wears out and loses it's seal

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cjnspecial said:

The 200T hasn't been running right for a while. It starts easy, idles way up then dies. If you hold down the throttle to keep it from dying, it would scream to over 17,000-18,000 rpm's. If didn't run it hard for a little while, it seemed like it would level out. It didn't do this all the time but it was getting worse and worse. Cleaning the carb and adjusting the H setting didn't help at all. All the rubber (fuel line, impulse line, vent, intake boot) were good. Because it was intermittent, I suspected an air leak and talked to my dealer about testing it and giving him the details on how it was running. He said not to bother bringing it in, to drop by the shop and he had what I needed in stock.
He says the new carbs are crappy and a lot of folks go back with a fully adjustable carb the 020t's use and have not had any issues with them.

Stihl PN: 1129-120-0650 /Zama C1Q-S32
**Note that Stihl also lists a fully adjustable Walbro Carb(Stihl PN 1129-120-0606/ Walbro WT-326D), just not sure if it's still available**

The carbs are the same except the H and L adjustment screws. Old carb on left, new on right.

Note the placement of the L adjustment is different. No big deal though.

Pic of the carb installed. The grommet fits over the H and Idle screws but not the L.

From start to finish, including pics, it took about 10 minutes. The saw runs perfect now. Hope this helps others out



If none of the above interests you, here is a gratuitous pic of homemade buckboard bacon.....Cured boston butts smoked 14 hours with green hickory. MMMMMMMM

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pgg said:

a 200T carb, the part that wears out, it's the brass plunger setup that rides off the throttle shaft, it pumps a squirt of gas to the main nozzle with the trigger from idle only. This one in the pic is worn and lets AIR direct to the main nozzle too

The accel- pump is another unnecessary crock of you know what. Same as the intelli-carb B.S. Jetted too lean for good low response, so they've had to add more clunky and troublesome moving parts in the form of the ridiculous accel-pump Which by the way, doesn't give any extra pep than a non-accel pump carb. And if people can't be bothered cleaning the airfilter occasionally then that's their problem. hahaha

The O-ring is what I blame for the air-leaks, close-up on this one, there's no tight seal, the O-ring is worn smooth and flush and seems limp with no spring to the rubber or whatever it's made of. Feels like rubber to me but could be nylon type stuff, maybe the new 200T carbs have better o-rings..

Also the carb alloy is harder than brass, the carbs alloy doesn't wear, it's the brass parts that wear down, not the alloy. Junk ethanol-laced fuel can't be much good for that o-ring either. I've never bothered, just thrown on non-accel carbs instead, but I reckon if you could find a replacement accel-pump O-ring, that 200T would likely run sweet again

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pgg said:

Well, I find the husky nicer to use than the 200T and the 200T shines on the bigger stuff only. Also I thought the 338's would have decent carbs, the 335 carbs have the main nozzle sitting too high, bad design, the idle circuit is starved and crappy at the best of times. My 335 has a better carb with a lower nozzle and runs flawless



Talking about 200T's, here's some info on their dodgy accel pump carbs, this leaky 200T carb has been hack-sawed in half for a looksee inside. Tracing the accel pump circuit, it runs to the main nozzle. On this one the O-ring on the accel pump piston is actually worn down to less diameter than the piston, but the bore and piston themselves are still pristine condition. That non-sealing O-ring leaks air directly to the main nozzle. Bung in a new O-ring, you'd be good to go again.


I hack-sawed my old carb for nothing.. Other option would be to do away with the stupid pump all together by prying off the small welch lid as in the pic, and epoxy/cement the pinhole beneath. That'll block the accel pump circuit. Re-tweak the lo & hi jets for good low response and you'd be sweet.. Good theory anyway, wish that saw mechanic Lakefront was still around, he could have sent me all those 'trashed' 200T carbs he'd thrown in the bin...

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1steve said:

3 of us only ones interested in fixing these carb's ?
great info you posted ZC thanks

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parrisw said:

Yes, just got home from work, threw the carb back together and put it on the saw. And.......................................
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It runs great!!!!!!!!!!! Got a few pics here of the carbs that I have here.

Video of the saw running with the carb with the plugged off pump circuit, is being uploaded now.

What I ended up doing is pulling the little tiny welch plug and filled that area with JB weld, as well I took the o-ring off the pump piston and filled the o-ring groove with JB weld and slid it back in the hole.

This is the one with the pump you can see the brass plug, its behind there.

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parrisw said:

Here it is.


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