The Jack's Small Engines Forum - Join Our Online Community
Reply to post

Chainsaw Stihl MS251C's tension knob is hard to turn

Author
Post
Essentials Only Full Version
zillah
New Member
  • Total Posts : 2
  • Scores: 0
  • Reward points: 0
  • Joined: 2025/08/25 04:17:12
  • Status: offline
2025/08/25 04:49:06 (permalink)
0

Chainsaw Stihl MS251C's tension knob is hard to turn

Dear Experts
 
I have got Stihl chainsaw MS251C hardly used

I found it is very hard to turn tension knob when chain gets loose

I have attached the photos showing no debris in the house and I can't see any damage

What further troubleshoots I need to consider to find where is the culprit ?

One video in the link below and few photos are attached
 

 
Thx
 
Quote  #1

3 Replies Related Threads
    SRTsFZ6
    Super Member
    • Total Posts : 2491
    • Scores: 80
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    Re: Chainsaw Stihl MS251C's tension knob is hard to turn 2025/08/25 07:26:43 (permalink)
    0
    https://www.diyspareparts.com/parts/stihl/diagrams/ms251-c/bf525355-2c1f-4cba-9150
     
    Above is a parts diagram of your chain tensioner assembly.
     
    Disassemble fully, clean and look for any worn parts.  
    When re-assembling, I like to use just a touch of engine oil on 
    most moving parts /  threads.
     
    Parts 1 and 2 are beveled gears and #2 especially is threaded. 
    Make sure they turn smoothly and that #2 isn't bent/jambed up in the housing.
     
     
     
    Advise
     
    .
    post edited by SRTsFZ6 - 2025/08/25 07:30:26

    Scott
    Quote  #2
    zillah
    New Member
    • Total Posts : 2
    • Scores: 0
    • Reward points: 0
    • Joined: 2025/08/25 04:17:12
    • Status: offline
    Re: Chainsaw Stihl MS251C's tension knob is hard to turn 2025/08/25 17:04:25 (permalink)
    0
    Thank you very much Scott for your help
    Quote  #3
    SRTsFZ6
    Super Member
    • Total Posts : 2491
    • Scores: 80
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    Re: Chainsaw Stihl MS251C's tension knob is hard to turn 2025/08/25 18:20:33 (permalink)
    0
    Your very welcome..
     
    Plz post back about the repair results..
     
     
     

    Scott
    Quote  #4
    Jump to:
    Copyright © 1994 - 2016 Jacks Small Engine & Generator Service, LLC
    © 2025 APG vNext Trial Version 5.5