ms200t help

[tree79]

Hi all

Just looking for a little help.

My ms200t struggles to hold full rev, it then dies at when at full rev.

It then doesn't start unless on half choke.

When I take the fuel Cap off there also a vacuum to.

 

 

I've clean the air filter, tank vent but still no better.

Any help would be great thank you.

 

 

[lurkalot]

Check the pulse pipe hasn't come disconnected from under the handle, make sure it is pushed on properly.

[billpierce]

Does it then run fine for a while after the vacuum in tank has been released? If yes then check that tank vent again! It should not be creating a vacuum.

[Stretchsaws]

3 hours ago, tree79 said:

 

 

Don't mistake a small build-up of fuel vapour in tank after running saw for a while for a vacuum.

Edited November 18, 2017 by Stretchsaws
didn't write anything first time round!

[tree79]

Thanks for you all help, will check the pulse pipe.

I did clean the tank vent, but you might be right it's not a vacuum. 

 

Will let you know my progress 

 

Thanks for your help

 

Tree

[Stubby]

As said . Possible split or disconnected  impulses pipe . Or usual accelerator pump piston fail .  

[joeblacky]

Doesn't sound like impulse,  it would most likely run like an absolute dog if it even ran at all. I'd pressure/ vacuum test the tank, it should hold pressure but leak down under vacuum. If that all checks out then it's time for a carb rebuild, as others have said most likely accelerator pump depending on the iteration of the c1q that you have.

[spudulike]

Sounds like the carb needs a full and proper rebuild - I am not just talking a few new rubber bits either! If the impulse had come off then the idle would be very fast and not good. The breather - if it has the dual fuel/breather fuel pipe, can be removed and a piece of pipe put on it and either pressure checked or just suck on it as the bishop said to the actress....but we digress 

Some depends on if the saws idle went loopy and someone has messed with the carb to accommodate it or if the saw just started bogging.

Worth checking the throttle and switch control shaft as if they are damaged, there will be little or no fast idle.

[Sambo]

On 18/11/2017 at 17:45, tree79 said:

Thanks for you all help, will check the pulse pipe.

I did clean the tank vent, but you might be right it's not a vacuum. 

 

Will let you know my progress 

 

Thanks for your help

 

Tree

It's quite hard to determine whether those tank vents are clear or blocked sometimes. It only needs to be allowing less in than is being sucked out by the carb diaphragm! For their tiny price I'd just bin it any way along with the fuel filter and get new ones! Might also be one of the diaphragm in the carb - again pennies!

[spudulike]

It has been a month now, would have thought the OP would have fixed it by now!