Stihl MS250 w/pulled bar studs

[Scottnc]

The local small engine go-to guy has asked for help fixing the pulled threads in an MS250 Stihl. Owner has already "fixed" it by first using red Loctite then tried screwing 7/16" bolts into the case. Of course neither worked and now the holes are off from their correct location and no longer perpendicular to the surface the bar sits on.

I like a dimensional print but mainly need the center to center spacing of the stock stud locations. Hopefully, the holes can be straightened and brought back their correct location in an oversize form to accept either a commercial thread insert, step-studs or tapped for a blank and the holes re-drilled to the factory size and thread.

 

[HarleyT]

There are Stihl oversize replacements, but it sounds like you need to replace the case.

 

[HarleyT]

Page #56 for the part numbers.

 

[Pioneer]

Cheap case here.

https://m.huztl.net/Crankcase-For-S...e-Housing-Chainsaw-1123-020-3003-p228812.html

 

[Scottnc]

Cheap case here.

https://m.huztl.net/Crankcase-For-S...e-Housing-Chainsaw-1123-020-3003-p228812.html

How can they manufacture, ship and then sell on the other side of the Pacific a decent case half for $13 and make money?? Are they worth using?

 

[Scottnc]

Page #56 for the part numbers.

Thanks, I'll call my Stihl dealer but I'm betting the holes are too wallowed out. Not to mentions crooked.

 

[HarleyT]

How can they manufacture, ship and then sell on the other side of the Pacific a decent case half for $13 and make money?? Are they worth using?

I think we all are already paying for that postage!!

 

[HarleyT]

Any older shop probably has a stack of these saws laying around that you could get real cheap. Just be sure to look and see if there is any damage around the chain brake hardware, as many junkers will have molten plastic in this area.

 

[HarleyT]

And yanked out bar studs usually mean that they have been running a shot sprocket.

 

[stihl86]

Either way, that sounds like a real money maker for than small engine guy.
The saw probably beat to hell. The stud is only one symptom.

 

[stihl86]

Either way, that sounds like a real money maker for that small engine guy.
The saw probably beat to hell. The stud is only one symptom.

 

[Scottnc]

Stihl's repair stud is $11. The case end is 9mm (factory was 8mm) with a thread style designed to form threads as it is cranked in. Supposed to be as good as the original if the problem is that the factory stud pulled straight out. That will fix one hole. The other, some bright light has cranked a 7/16-14 bolt into until the threads pulled again. Rocket scientists abound, eh? A 7/16-14 Heli-Coil could work, never put one in plastic before but I have tapped plastic, found it is not uncommon for the threaded hole to remain a bit undersize once tapped. That could be an issue if using a 7/16 bolt as a hole filler. Adjusting a die down, then running it over the bolt to undersize it should work. The bolt can be drilled and tapped first - IF a tap matching the factory stud is available - have not verified if it is a legit metric thread pitch or something goofy for plastic.

If any of you have traveled this road before I'd appreciate some feedback.

 

[pioneerguy600]

How much do you want to pay for the time involved/labor to rectify this problem? Just asking for a friend, that has done this repair before.

 

[HarleyT]

Yeah, I travelled that road one time. If the oversized studs won't work, find another case.

Or find another project....

 

[HarleyT]

When working on this **** for a living, you will find out quickly that cheapo rigging does no good, and will just hurt your reputation. I spent more time talking folks out of letting me fix their saw, mainly because if I wasn't allowed to fix the saw correctly because of the money involved, the repair wouldn't last long, and the customer would go out of his way to bad-mouth me for the rest of his life. Many folks here just join the site just to badmouth someone or some brand of saw.

 

[PogoInTheWoods]

Find a good used tank/housing or it'll come back to haunt you.

 

[HarleyT]

Find a good used tank/housing or it'll come back to haunt you.

Yes!!

 

[PogoInTheWoods]

A couple on the bay right now for $30~$40. I think the oversized replacement studs can run around 10 bux apiece themselves. 1123-020-3033 is the flip cap tank version. 3003 is the screw cap version. 3034 is an ez-start version that has different coil mountings.

Rebuilding one of these saws is a one hour job if you've done a couple. Quite an elegant design in it's simplicity, actually. You'd spend more time trying to fix the studs than just replacing the housing. Ask me how I know...

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[Scottnc]

Is the case splitter/support tool required when splitting a plastic case?

 

[HarleyT]

Is the case splitter/support tool required when splitting a plastic case?

No, the engine/block bolts on top of it.