Ms200t will start but won't idle or stay running

[Conor Owens]

Hello all.

I acquired a ms200t saw today. It will fire if you put on full choke then to half choke and then onto on position. It will idle erratically for some time sometimes it will idle for a while sometimes just cut out. When pressing the trigger it wants to die and alot of the time stalls. I have cleaned the coil, it has a good spark. I have taken the carb to bits and cleaned. I have tweaked the L screw and idle screw but i can not get it to run correctly. What are peoples thoughts is it something else that is the problem or it needs a better fine tune?

 

[Ozhoo]

Impulse hose would be your next logical check.

 

[Conor Owens]

Impulse hose would be your next logical check.

What am I looking for ?

 

[Ozhoo]

What am I looking for ?

Cracks, abrasion, dry rot, slipped off the nipple... see this thread

 

[lone wolf]

Hello all.

I acquired a ms200t saw today. It will fire if you put on full choke then to half choke and then onto on position. It will idle erratically for some time sometimes it will idle for a while sometimes just cut out. When pressing the trigger it wants to die and alot of the time stalls. I have cleaned the coil, it has a good spark. I have taken the carb to bits and cleaned. I have tweaked the L screw and idle screw but i can not get it to run correctly. What are peoples thoughts is it something else that is the problem or it needs a better fine tune?

Where can we start,what setting arethe H and low needles at?
Does it have good compression?
Has the fuel filter on the hose fallen off?
Is the impulse line under the air filter housing on the left side on?
Did you blow compressed air through the carb that will possibly ruin it?

 

[Conor Owens]

Where can we start,what setting arethe H and low needles at?
Does it have good compression?
Has the fuel filter on the hose fallen off?
Is the impulse line under the air filter housing on the left side on?
Did you blow compressed air through the carb that will possibly ruin it?

I set the high and low screws to all the way in and one full turn out. That doesn't work. Tried tweaking them but it doesn't run long enough for me to try and tune them. I've just looked at the impulse pipe. It was attached both ends, doesn't appear to be any damages but I haven't taken it out. Compression- it starts and revs high when it wants to.. surely lack of compression wouldn't allow this ?

Could you give me steps on what you would do if i gave you this saw.. ie a process of elimination

 

[lone wolf]

I set the high and low screws to all the way in and one full turn out. That doesn't work. Tried tweaking them but it doesn't run long enough for me to try and tune them. I've just looked at the impulse pipe. It was attached both ends, doesn't appear to be any damages but I haven't taken it out. Compression- it starts and revs high when it wants to.. surely lack of compression wouldn't allow this ?

Could you give me steps on what you would do if i gave you this saw.. ie a process of elimination

Another carb is what I would do at this point ,providing you set the screws at 1 out ea. Did you use compressed air to blow it out? Is the fuel filter on and the gas not split? Sounds like the carb if it ain't its a vac leak in the engine. Can you borrow a carb from a known runner? Dont by cheap China carbs . Your in the UK ?

 

[Conor Owens]

Another carb is what I would do at this point ,providing you set the screws at 1 out ea. Did you use compressed air to blow it out? Is the fuel filter on and the gas not split? Sounds like the carb if it ain't its a vac leak in the engine. Can you borrow a carb from a known runner? Dont by cheap China carbs . Your in the UK ?

I only brought the saw todsy, it wasn't working. I managed to get it running somehow just like a bag of . So I don't know what the previous owner could have done to it. I don't have another or know anyone with a ms200t. I'm in the UK yes

 

[lone wolf]

I only brought the saw todsy, it wasn't working. I managed to get it running somehow just like a bag of . So I don't know what the previous owner could have done to it. I don't have another or know anyone with a ms200t. I'm in the UK yes

Sounds like the carb,check the fuel line and filter is the carb mounted securely? These carbs are expensive. It just occured to me you said you cleaned the carb? You need to put a rebuild kit in it then try again if that fails your only viable option is to replace the carb! Unless you are skilled enough to rip that whole saw down and do a vac - pressure test which could also be the problem. So rebuild the carb with a kit next step.

 

[Conor Owens]

Sounds like the carb,check the fuel line and filter is the carb mounted securely? These carbs are expensive. It just occured to me you said you cleaned the carb? You need to put a rebuild kit in it then try again if that fails your only viable option is to replace the carb! Unless you are skilled enough to rip that whole saw down and do a vac - pressure test which could also be the problem. So rebuild the carb with a kit next step.

This is the saw in mention, these video is after playing around with h/l and ideal screws. As you can hear it sounds okay. I gave it some revs and it revved but eventually stalled. But it still won't run Right. I start it up now and it won't idle at all but if I press the accelerator in straight away it will rev high like it should untill I let go of the trigger. It will also run fine in half choke position. the links will take you to youtube where I have uploaded the vids.
Appreciate your help.

 

[lone wolf]

This is the saw in mention, these video is after playing around with h/l and ideal screws. As you can hear it sounds okay. I gave it some revs and it revved but eventually stalled. But it still won't run Right. I start it up now and it won't idle at all but if I press the accelerator in straight away it will rev high like it should untill I let go of the trigger. It will also run fine in half choke position. the links will take you to youtube where I have uploaded the vids.
Appreciate your help.

You migght blow that up slow down the rpms,its running lean as hell if the H jet out a tiny bit more dont fix it rebuild the carb if that dont work buy a carb. Stop reving it like that so long.

 

[lone wolf]

You migght blow that up slow down the rpms,its running lean as hell if the H jet out a tiny bit more dont fix it rebuild the carb if that dont work buy a carb. Stop reving it like that so long.

 

[Conor Owens]

I thought that. But that is with the h screw tuned. It's at he point of which it's least revs! So I'm not sure what's wrong with it. When you mean rebuild the carb. You mean the full needle ect ? Or just the metering diaphragm and gaskets ?

 

[lone wolf]

I thought that. But that is with the h screw tuned. It's at he point of which it's least revs! So I'm not sure what's wrong with it. When you mean rebuild the carb. You mean the full needle ect ? Or just the metering diaphragm and gaskets ?

Where are the H and L screws set in that video at 1 turn out each are you near sea level? What happens if you turn both out an 1/8 more ea? Yes just the diaphragm and fuel pump and gaskets. It is either a bad carb or an air leak are you able to vac test the saw if so it wont cost nothing just to do that? If you eliminate the vac leak you can be assured you need a carb? But are you able if not go the carb rebuild then new route.

 

[Conor Owens]

Where are the H and L screws set in that video at 1 turn out each are you near sea level? What happens if you turn both out an 1/8 more ea? Yes just the diaphragm and fuel pump and gaskets.

The H screw set one turn out. Nd l screw set at one turn out but teaked a little for it to stay running the longest. I'm in city so yes sea level

 

[lone wolf]

The H screw set one turn out. Nd l screw set at one turn out but teaked a little for it to stay running the longest. I'm in city so yes sea level

Like I said air leak or carb . Usually the carb.

 

[Conor Owens]

Like I said air leak or carb . Usually the carb.

What will be the fault with the carb ? Is it mendable?

 

[lone wolf]

What will be the fault with the carb ? Is it mendable?

Try the kit first then we can go from there . Dont put high pressure air through it.

 

[Conor Owens]

This is the piston. Would you say this it damaged enough for it to cause this issues ?

 

[Tobystihl]

Carb problem sounds like accelerator pump issues, cylinder has carbon scoring, you may get away with cleaning up the cylinder and replacing the piston but it will probably need a new pot and piston