JOEPRO
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This is cleaved from my MS201 separate thread as it's really a method on its own and I'd like to hear opinions on this subject please.
I have just carried out a top end rebuild of a used Stihl MS201 saw I got from ebay. I didn't run before and the old piston had some exhaust port scoring on it.
I have sealed the intake and exhaust ports and applied vacuum to the crankcase breather per the photos. It holds steady for about 10 seconds then very slowly starts to decay. It would take minutes for it to discharge fully. Does this look reasonable to say the crank seals are likely OK or must I also carry out a pressure test? (If so I'll need to buy another tester which is fine)
![20240723_211100.jpg 20240723_211100.jpg](https://www.mig-welding.co.uk/forum/data/attachments/454/454600-175962b462d1614ab3c5f5449f8b2934.jpg)
![20240723_211751.jpg 20240723_211751.jpg](https://www.mig-welding.co.uk/forum/data/attachments/454/454601-81130d05702a7e9db7ddb2698cca47c7.jpg)
![20240723_211755.jpg 20240723_211755.jpg](https://www.mig-welding.co.uk/forum/data/attachments/454/454602-1a7b34d6182e837e8ab3dafd64bdc056.jpg)
I have just carried out a top end rebuild of a used Stihl MS201 saw I got from ebay. I didn't run before and the old piston had some exhaust port scoring on it.
I have sealed the intake and exhaust ports and applied vacuum to the crankcase breather per the photos. It holds steady for about 10 seconds then very slowly starts to decay. It would take minutes for it to discharge fully. Does this look reasonable to say the crank seals are likely OK or must I also carry out a pressure test? (If so I'll need to buy another tester which is fine)
![20240723_211100.jpg 20240723_211100.jpg](https://www.mig-welding.co.uk/forum/data/attachments/454/454600-175962b462d1614ab3c5f5449f8b2934.jpg)
![20240723_211751.jpg 20240723_211751.jpg](https://www.mig-welding.co.uk/forum/data/attachments/454/454601-81130d05702a7e9db7ddb2698cca47c7.jpg)
![20240723_211755.jpg 20240723_211755.jpg](https://www.mig-welding.co.uk/forum/data/attachments/454/454602-1a7b34d6182e837e8ab3dafd64bdc056.jpg)