Stihl 201tc tank vent leaking fuel

[Tomthetree]

I have a stihl 201tc and today noticed a small leak of fuel coming from the tank breather just under the air filter cover. 
should I replace the tank breather ?

I have read they shouldn’t leak fuel?

 

This is where the fuel was leaking from and when I had the saw hung on my harness it was worse

I had a look at the saw in this orientation and could see fuel coming out of what I now know is the tank vent 

 

any help? Thanks

[Paddy1000111]

I would get in there and see what is actually leaking first. The breather consists of:

 

• Grommet (1141 989 0600)
• Elbow (1145 122 3900)
• Hose  (1145 358 7706)
• Valve/Vent (0000 350 5802)

All the parts are "two a penny" so you could order them all and just replace the lot if you need it asap or you could inspect it and see what's wrong and save some money. Something could have just popped out of place/chafed through.

[Tomthetree]

Hi thanks. 
I have got in there and the fuel was definitely coming from the breather 100%
 

I tried pulling the breather out and pushed it back in maybe it will be ok

 

will a leaking tank breather have any effect on the saws performance?

 

should I just replace it anyway?

[Paddy1000111]

Which part is actually leaking? 

[Tomthetree]

It was coming out of the bottom of this part

 

I just lifted this part up and some fuel dribbled out

i don’t want to force the piece out but seems abit tricky to get it fully out

[Paddy1000111]

It should just pull out. You can pull that pipe off that's connected to it too. If you have a vacuum/pressure gauge you can test it. It should hold pressure but not vacuum. If you don't have that then you can blow/suck on the port although you might get a nice taste of fuel. 

 

In terms of performance it shouldn't make any difference assuming that it's not holding vacuum or the saw will cut out/run lean. 

Edited December 22, 2020 by Paddy1000111

[Tomthetree]

Thanks for the reply’s. 

im going to replace the can’t vent and also a new fuel filter. The saw seems to be running rich is anything. Occasionally hesitates as I go full throttle and take some blips of the trigger to get the revs up and the spark plug looks carbon fouled so I will do the vent and filter and see if there is any difference. 
also putting a new spark plug in

[Paddy1000111]

5 minutes ago, Tomthetree said:

Thanks for the reply’s. 

im going to replace the can’t vent and also a new fuel filter. The saw seems to be running rich is anything. Occasionally hesitates as I go full throttle and take some blips of the trigger to get the revs up and the spark plug looks carbon fouled so I will do the vent and filter and see if there is any difference. 
also putting a new spark plug in

Replace the vent and do an mtronic reset (warm it up, turn it off, start it in choke and leave it in choke for 90 seconds then turn it off, don't blip the throttle or rev it between choke and shutdown) 

 

I got it all the time with a 201. Warmed it up, made a load of cuts and then up in the tree and it would either fire then stall or bog and need the throttle feathered. There is an Mtronic update/repair kit for the 201t for about £60 with a new carb, ignition module and flywheel

[spudulike]

On 01/01/2021 at 21:41, Paddy1000111 said:

There is an Mtronic update/repair kit for the 201t for about £60 with a new carb, ignition module and flywheel

There is an upgrade kit for the MS201t as the early ones were diabolical.

The upgrade kit for the Mtronic MS201TC (which this one is) was the solenoid and a new orange fuel filter as particles were getting through to the earlier solenoids causing poor idle.

I think you have got the facts all mixed up, no disrespect meant!😉

[Paddy1000111]

35 minutes ago, spudulike said:

There is an upgrade kit for the MS201t as the early ones were diabolical.

The upgrade kit for the Mtronic MS201TC (which this one is) was the solenoid and a new orange fuel filter as particles were getting through to the earlier solenoids causing poor idle.

I think you have got the facts all mixed up, no disrespect meant!😉

I realised that after I posted it and went to get a link and they were all for the MS201t... I could have sworn I saw one but I am obviously wrong 🤦‍♂️ Don't suppose you have the update p/n?