MS200T Starts but won't tick over or run up

[aquatoo]

I have an MS200t, which I bought second hand and have used with no bother. I tried it the other day and although it starts easily it won't tick over or run up correctly.

 

I have changed the fuel pick-up filter and made sure that the fuel line is clear, changed the plug, cleaned the air filter, stripped the carb to make sure it is clean and tried resetting the carb and adjusting it. No joy!

As the grommet on the side of the carb housing was missing I assumed that the sawdust getting inside may have had something to do with it. I cleaned it all out while removing the carb. (I have ordered a new grommet)

 

If I adjust the idle screw so that it revs faster it still won't continue to run. Oddly if I tip the saw on its side it runs better but still stalls.

 

What is the tube that runs up the left hand side of the filter housing, next to the fuel pipe and ends in a bulbous moulding with lots of dots on the face and pushes into a moulding in the housing?

 

Any idea what might be wrong.

[Stubby]

Sounds like your tank breather could be blocked . Try starting the saw on its side with the fuel cap off . If it runs up ok the its a blocked tank breather .

[aquatoo]

Sounds like your tank breather could be blocked . Try starting the saw on its side with the fuel cap off . If it runs up ok the its a blocked tank breather .

 

Thanks Stubby I'll check that as soon as I get home.

[aquatoo]

I've just downloaded a workshop manual. Seems that the bit I was asking what it is, turns out to be the breather!

[Rich2484]

Could be the crank seals. If its on its side a runs better the crank is moving against the seal and stopping the air leak in the crank case.

 

Of course the breather could also be the problem.

[spudulike]

Possible air leak, crank seals as Rich says. The tube is the tank vent, the top part will pull off and you should be able to sick air through it.

 

The carbs on these saws can give strange issues that may need an ultrasonic clean or other work done but can be eliminated by fitting another good carb to see if it is the issue or not!

 

If you get stuck, PM me:thumbup:

[Rich2484]

Or me.

[aquatoo]

Fixed it. Thanks all.

 

Stripped and thoroughly cleaned the carb, cleaned the tank vent, reset the carb to basic settings and it now runs and ticks over.