Ms194T Only runs with the Choke on

[Justin Saunders]

I just picked up an MS194T from ebay. I replaced the spark plug, cleaned the air filter, and did my best to set the carb to manual specs then minor adjustments. With the choke on (choke blade fully opened), the saw runs great. I have it idling, no bog off the bottom end and revs out really nice. The problem is as soon as flip the choke off (choke blade closed) the saw dies essentially immediately. This is my first saw but I've owned dirt bikes for a while so I'm not new to small engines or carbs. My immediate thought is I just had my H and L adjustments off but nothing I do to them get the saw to even idle with the choke off.

- My carb adjustment limiters are still on, H is 1/8 turn out. L is 1/4 turn out.
- Fresh CMR6H plug (old plug had a nice tan color)
- Fresh non ethanol fuel mixed with stihl's recommended 2 stroke oil.

I've done my best to youtube and goggle answers but I'm coming up blank!
Any ideas would be much appreciated!

 

[DND 9000]

Well it seems that you have very litte experience with saws. That is completely normal what your saw does. With the choke on (Chocke shutter closed) the saw can`t run, because the engine can only suck a tiny amount of air. This is only for the cold start to richen the mixture. With the open choke shutter the saw can run normally at idle, part throttle or full throttle.

Read the owners manual how to operate the saw or ask your friendly dealer to show you how it is done correctly.

 

[ZeroJunk]

I think he may be mixing up his open and closed.

 

[Old2stroke]

Choke off, no choke, choke open mean the same
Choke on, choke closed, full choke mean the same

 

[lone wolf]

I just picked up an MS194T from ebay. I replaced the spark plug, cleaned the air filter, and did my best to set the carb to manual specs then minor adjustments. With the choke on (choke blade fully opened), the saw runs great. I have it idling, no bog off the bottom end and revs out really nice. The problem is as soon as flip the choke off (choke blade closed) the saw dies essentially immediately. This is my first saw but I've owned dirt bikes for a while so I'm not new to small engines or carbs. My immediate thought is I just had my H and L adjustments off but nothing I do to them get the saw to even idle with the choke off.

- My carb adjustment limiters are still on, H is 1/8 turn out. L is 1/4 turn out.
- Fresh CMR6H plug (old plug had a nice tan color)
- Fresh non ethanol fuel mixed with stihl's recommended 2 stroke oil.

I've done my best to youtube and goggle answers but I'm coming up blank!
Any ideas would be much appreciated!

When the BUTTERFLY VALVE is fully open, the choke is off! When it's closed, choke is on!

 

[lone wolf]

Here is a pic with the choke off.

 

[HansFranz]

With the choke on (choke blade fully opened), the saw runs great. I have it idling, no bog off the bottom end and revs out really nice. The problem is as soon as flip the choke off (choke blade closed) the saw dies essentially immediately.

Think about how a choke works. When the choke butterfly is closed -- in other words, blocking or choking airflow through the carburetor -- it creates more vacuum at the venturi when you turn over the motor. This draws more fuel into the engine, helping it to start when cold (or flooding it, if you do it too much). The standard description of this condition is that "the choke is ON."

With the choke butterfly open (i.e., NOT blocking or choking the air passing through the carb) it doesn't create as much vacuum at the venturi, and so less fuel is drawn from the jet into the engine, thereby preventing flooding, and allowing for a "standard, normal operating temperature" fuel-air mixture. The standard description of this condition is that "the choke is OFF."

As others said, I think ya got things backerds. You turn the choke ON to start a cold saw. You turn the choke OFF as soon as possible after getting the saw started.

 

[Wood Doctor]

"You turn the choke OFF as soon as possible after getting the saw started."
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And in some cases when the saw acts like it's ready to start or when it just fires a tad to let you know that it's ready to run.

 

[ZeroJunk]

Number 1 issue that comes in the store as won't crank is flooded.

You can always take it off choke and see if it will start, and if not choke it some more.
But, if you really get it flooded you are through for a while.

 

[Gibby II]

Sounds to me like the carb diaphragm's are old are not as pliable as when new. I see it a lot on my model airplane engines and chainsaws. Would all most bet money just changing the diaphragm's would solve his problem. Just my 2cents

 

[HansFranz]

Number 1 issue that comes in the store as won't crank is flooded.

You can always take it off choke and see if it will start...

+1

It took me a while to learn this, but one of the best ways to clear a flooded saw is to turn off the choke and pull the starter cord about 10,000 times while holding the throttle trigger WFO.

 

[lone wolf]

+1

It took me a while to learn this, but one of the best ways to clear a flooded saw is to turn off the choke and pull the starter cord about 10,000 times while holding the throttle trigger WFO.

With the plug out and air filter off to clear it out, then leave the air filter off for initial start.

 

[stihltech]

We need an answer back. What did you find? Are you starting the saw correctly? Is it flooded? As stated before, this is the most common issue in a shop.
Verify the complaint before firing the parts cannon.