Husqvarna 550 xp Chain brake

[ecovandal]

Hi,  I've acquired a 550xp Husqvarna.  Lovely saw, in fact it's dragging me away from the 357's I normally use.  However the chain brake isn't working due to the damaged raised, threaded plug that sits in the chain brake recess acting as a locking hinge, .  I've tried various repairs with different araldite type fillers to 'remake' the raised plug but they only work for a short period of time.  I'm thinking the best way of doing it is to drill out the enlarged hole and put in a metal tube with a flange on the exhaust side and put a thread in for the chain brake screw.  The problem is I don't have such a thing lying around my shed .  Does anyone have such a thing, or direct me as to where I could find one  or maybe someone could suggest a better/easier repair.  All ideas are welcome.

The first two photo's attached show the problem and the last what the actual part should look like.

Many Thanks

[NFG]

Helicoil insert?

[openspaceman]

57 minutes ago, ecovandal said:

Does anyone have such a thing, or direct me as to where I could find one  or maybe someone could suggest a better/easier repair.  All ideas are welcome.

You don't mention a size, I'm guessing either M5 or M6?

 

Either a rivnut insert (may need to knock a depression in the exhaust) or a flanged threaded insert.

 

https://www.amazon.co.uk/ASSORTED-DRIVE-SCREW-THREADED-INSERT/dp/B06XFHF5GY?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B06XFHF5GY

 

https://www.amazon.co.uk/Plated-Carbon-Nutsert-Threaded-Assortment/dp/B071JS4D6M?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B071JS4D6M

 

Or if you need more bearing area at the back these with the tangs ground off and a dob of araldite to adda bit of strenght (mind it fails at 200C and next to the exhaust...

 

https://www.amazon.co.uk/Pack-Metal-T-Nut-Fixings-Furniture/dp/B0748HFK5F?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0748HFK5F

 

I bought stuff from

 

http://www.theinsertcompany.com/index.php

 

and successfully repaired a few of the handle mounts of Stihl brushcutters when the threads wore out. Saved about £40 each time.

 

You will need to know the thread size before you order and whether there is scope for going up a millimetre

[Wolfie]

Exactly the same part broke on my 372. Never found a fix that would hold for more than 5 mins. I think that it's a bad design by Husqvarna, a lot of pressure gets put on that small pin.

[peatff]

Could you take the exhaust off and drill through then fit a countersunk head bolt from the rear and a nut on the front ?

[spudulike]

Think it is one of those repairs that you need the saw in front of you to asses what can be done. I think the original screw has a screw thread rather than being M5/M6. Can you put a bolt all the way through with spacers where they are needed?

Just remember, the chain brake is there for a reason and an unsafe repair isn't a good one!

[ecovandal]

8 minutes ago, spudulike said:

Think it is one of those repairs that you need the saw in front of you to asses what can be done. I think the original screw has a screw thread rather than being M5/M6. Can you put a bolt all the way through with spacers where they are needed?

Just remember, the chain brake is there for a reason and an unsafe repair isn't a good one!

Thanks for that - agreed.  The screw itself is an M5 - but that goes into the bit that is now missing.  Other suggestions above may work but it's difficult to find 'a thing' that is long enough and to be able to hold into the saw whilst having a thread inside it to bolt to ..like you said easy to see/explain with the saw in hand.

 

7 hours ago, openspaceman said:

You don't mention a size, I'm guessing either M5 or M6?

 

Either a rivnut insert (may need to knock a depression in the exhaust) or a flanged threaded insert.

 

https://www.amazon.co.uk/ASSORTED-DRIVE-SCREW-THREADED-INSERT/dp/B06XFHF5GY?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B06XFHF5GY

 

https://www.amazon.co.uk/Plated-Carbon-Nutsert-Threaded-Assortment/dp/B071JS4D6M?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B071JS4D6M

 

Or if you need more bearing area at the back these with the tangs ground off and a dob of araldite to adda bit of strenght (mind it fails at 200C and next to the exhaust...

 

https://www.amazon.co.uk/Pack-Metal-T-Nut-Fixings-Furniture/dp/B0748HFK5F?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0748HFK5F

 

I bought stuff from

 

http://www.theinsertcompany.com/index.php

 

and successfully repaired a few of the handle mounts of Stihl brushcutters when the threads wore out. Saved about £40 each time.

 

You will need to know the thread size before you order and whether there is scope for going up a millimetre

Thanks for the extensive reply.  Didn't realise that there was so much stuff out there like the inserts.  I've had a good rummage around . Something may be useful.  Just tricky to get something that covers all bases and is long ( at least 16mm) strong enough.

 

[adw]

I have tried to repair these in the past, it only lasts a short while before the hand guard starts to slop around and the screw falls out, changing the crankcase is usually the best way to go, there is so little material to work with in this area, you can usually find a s/h half.