I bought an MS201T recently. It seems to have had a fairly hard life. I can get it to start, run and cut reasonably. But only with the low screw backed off two full turns. Factory setting is a 1/4 turn. To me that suggests a problem. I put a carby kit through it but no change. Any suggestions or advice would be appreciated
MS201T low screw setting
- Thread starter Cogito
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Do a pressure and vacuum test. It is possible that you have leaking seals.
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Gone fishing
I think he might be meaning the crankshaft seals, located outside the crankshaft bearings, on the inside of the clutch on one side and flywheel on the other.
Usually the problem you describe that you cant get it to run properly especially at idle/low rpm and that you need to rich it; is caused by air bypassing the carburettor in to the cylinder bottom end/crankcase. So if you have any old rubber like an impulse tube not fitted properly or a carburettor manifoil with a crack in it those could do it as well.
Usually the problem you describe that you cant get it to run properly especially at idle/low rpm and that you need to rich it; is caused by air bypassing the carburettor in to the cylinder bottom end/crankcase. So if you have any old rubber like an impulse tube not fitted properly or a carburettor manifoil with a crack in it those could do it as well.
I'm hoping my carrier pigeon reaches you. Are those seals accessible without splitting the crankcase and are there any visual clues for leaks. It seems I may need to acquire a pressure/vacuum tool but I have read on this forum the need for specialised adaptors.
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Gone fishing
I'll let someone else answer that, I'm not familiar with the MS201T.
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Gone fishing
It's all just fun, when you get it sorted you have learned alittle too I would guess, and you will be more confident to repair, fix or service your own saw.
I was hoping the wolf guy would chime in on you, he would know everything about that saw and what any problems might be, and just how to solve them.
You will most probably not need to split the crankcase to change the crank seals, but you need to remove the clutch and the flywheel.
The clutch threads are usually "links" or the wrong way so to speak so be observant not to just tighten it when what you really want is to loosen it.
To stop the crankshaft from turning you can use a piece of rope in through the spark plug hole so that the piston is prevented to reach the top of the cylinder.
The crank seals are peeled out with a modified screwdriver or similar, search youtube and at this forum. Be careful not to scratch the seal seat surface.
By the time you have aquired the pressure and vacuum gauges and figured out how to use them, you could be finished changing those seals already.
Make sure there is no place that may leak air between the carburettor and the cylinder.
I was hoping the wolf guy would chime in on you, he would know everything about that saw and what any problems might be, and just how to solve them.
You will most probably not need to split the crankcase to change the crank seals, but you need to remove the clutch and the flywheel.
The clutch threads are usually "links" or the wrong way so to speak so be observant not to just tighten it when what you really want is to loosen it.
To stop the crankshaft from turning you can use a piece of rope in through the spark plug hole so that the piston is prevented to reach the top of the cylinder.
The crank seals are peeled out with a modified screwdriver or similar, search youtube and at this forum. Be careful not to scratch the seal seat surface.
By the time you have aquired the pressure and vacuum gauges and figured out how to use them, you could be finished changing those seals already.
Make sure there is no place that may leak air between the carburettor and the cylinder.
SteveSr
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How to summon the Wolf (or anyone else for that matter... @lone wolf
Can you do a compression test?
Are you able to do a Vac and pressure test on the saw?
If you cant do the complete teardown and Vac test and it has good compression which would be towards 160 then try a new OEM carb not Chinese.
fyi- factory setting of low speed screw is 1 to 1-1/4 turns out without limiter cap
the 1/4 only applies when limiter cap is on screw.
the 2 turns out could be from its hard life as you said and compression may be down, or slight air leak as mentioned already
the 1/4 only applies when limiter cap is on screw.
the 2 turns out could be from its hard life as you said and compression may be down, or slight air leak as mentioned already
How can you be sure the setting is 1/4 does it say that on the saw? And what does it say for the H?
I got the settings from an MS 201T manual online. The hi setting was fully open (counterclockwise until stop). The lo was clockwise until stop, then back 1/4 turn. It did say that you could turn the lo further counterclockwise if the saw was running poorly. Two full turns just seemed a lot to me. I think I will give it a good workout and see how it goes. If it plays up I may look at investing in a pressure testing device. Thanks for the help. This forum seems to have a wealth of information.
I replaced the fuel tank vent valve which has made it less erratic. Bit of an amateur mistake not replacing all the cheap components at the start. It still needs the low screw to be set rich but doesn't seem to miss a beat now and I'm test cutting through dry jarrah (a notorious West Australian hardwood). Thanks for all the help, I'm sure I will return as I am attempting a full rebuild of a MS201TC Mtronic.
