Jump to content
  • Sign up now

    Registration is quick and easy 

Husqvarna 125 crank seal issue

Black Mountain Rider

Recommended Posts

Hi Everyone,

I am new to this forum and hope you can offer some advice on a problem with a Husqvarna 125. The bike belongs to

my neighbours son who recently purchased the bike in supposedly good running order. Unfortunately it seems it has been in the hands of someone who

has not been to kind to it in the past. Having some mechanical knowledge I have offered my help to try and sort out some of the issues, my main interest is with

vintage stationary engines so this is a little different for me. The problem we have at present is oil leaking from the casing on the ignition side. I am guessing this is a crankcase seal gone or maybe the bearing as well? We took the cover off and found what is in the photo attached.

My questions are;

I presume the centre nut holds the rotor on via a woodruff key...would this be a right or left handed thread?

Can the seal be accessed from outside or will the engine need to be split?

Hope someone can offer some advice about how we proceed next, it's been a frustrating journey so far for the lad.

Thoughts appreciated.



Link to comment
Share on other sites

Hi Tim, welcome to the forum.

It should be a normal r/h thread, so when engine running the nut tightens up. When you undo nut there may be a internal thread inside flywheel, that takes a puller and pulls off flywheel.

As you say it's on a tapered shaft with a woodruff key. Once you remove flywheel there's normally another plate that has the stators on, then behind that is the seal.

The seal sometimes can be removed from engine at this point, But on some 2 strokes the seal has a lip and can only be fitted after a complete engine strip and fitted from the inside.

The Bearing is normally fitted to the crankcase, again only ever fitted internally.

I would see if you could locate a manual, or a crankshaft seal to see if there's a lip on it. And if you have oil coming out then it may mean r/h seal has also gone allowing oil from gearbox into combustion chamber. :oops:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

Terms of Use Privacy Policy Guidelines We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.