261 clutch drums splitting?

[Snedasawrus]

Hello arbtalkers. Have had my MS 261 for 3 and a half years now. Did have trouble in the beginning with the classic needle bearings problem, but stihl took it away and rebuilt the crankshaft and changed the clutch drum. After that I had no trouble for a long time. But now for the second time in 3 weeks this has happened. Any ideas as to why? My only thinking is that their is something wrong with the crank again?

 

Thanks

[humpo48]

Looking at your pics seems a bit too much of a coincidence the clutch drums have broke in the same place. Did you buy the clutch drums the same time, just thinking they are from the same batch?

Edited June 3, 2015 by humpo48

[kinderscout]

I am no expert but it looks as if you need a complete new clutch as the springs and pads are very worn,allowing excessive expansion of the clutch?

[spudulike]

Is it a fracture in the metal or has it worn the drum paper thin until it wore through?

 

If it is wear, it is probably your clutch springs and if it has fractured, the metal of the drum may be too hard.....weird, never seen that before!

[Stubby]

Looking at your pics seems a bit too much of a coincidence the clutch drums have broke in the same place. Did you buy the clutch drums the same time, just thinking they are from the same batch?

 

How do you know its the same place ?

[humpo48]

How do you know its the same place ?

 

 

Hi Stubby, where the pin fits in the groove/cut out for the oil pump, they have both split the same side of the groove .

[kinderscout]

I have seen this on a model helicopter this had a tapered set of shoes,pushing the top of the clutch out.it looks identical to these photos.

[Stubby]

Hi Stubby, where the pin fits in the groove/cut out for the oil pump, they have both split the same side of the groove .

 

Ah I understand .

[Snedasawrus]

One of the drums was put in by stihl about a year and a half ago and cracked 3 weeks ago. Replaced with new one and it went today. Was glowing red hot and has melted a lot of the plastic around the drum! The drums are fractured in just the one place, no sign of wear on any other area. Will replace clutch and see what happens. Cheers

[Stubby]

Its gonna go again surely ?