Stipped thread repair

[dstaton]

I have a spline screw that about to strip out the threads in my stihl 088. The size of the screw is M4x12. In your experience, what is the best way to repair these threads? This is the screw that holds the inner cover plate on. (goes over the bar studs, covers the oil passage etc...) I realize that it is not major, but I like to keep things in repair. Thanks for your ideas.

 

[JimL]

Case like that, theres quite a few options...

Can you drill deeper and tap it out, insert longer screw?
Can you drill bigger and tap for 5mm?
Can you insert an helicoil?


Lots of options...

 

[oakman]

tap out to 5mm, or helicoil

 

[Fish]

Helicoil. Some older Stihls came with helicoils already in place.
A 4mm kit costs @ $45

 

[tony marks]

well im dam sure gonna try it oakman.
sounds like somethin an ole gimmirigger
like me can use. guess u wait too long
and that bolts in there permanent huh.

 

[oakman]

helicoil. only thing that will work

 

[John in MA]

I actually bought a Stihl 032 that someone had used some kind of thread repair epoxy on to repair a stripped-out bar stud hole. Didn't work too well for that. I Helicoiled it and it's been fine ever since.

 

[bwalker]

There is a product simular to helicoil called time-sert. Time-serts are way more durable and rugged so i would go that route. JB weld type stuff seems like a bandaid fix to me.

 

[treeclimber165]

For the particular screw that he has a problem with, I would think one of the 'band-aid' deals would work fine. The only time this screw actually holds anything is when the bar is removed. It cannot back out because of the side cover when running the saw, and I have seen many saws without any retaining screw for that inside plate.

For a screw that actually holds something, I'd want a heli-coil of some type or drill and re-tap to a larger size.

 

[tony marks]

now i got a new project. gonna find out what a helcoil is. if it works i want to know about it.

 

[treeclimber165]

Tony-
A helicoil looks like a steel spring. You drill and tap a larger hole and screw the spring into the hole. The inside of the spring is the right size thread for your bolt or screw.

(Extremely simplified explanation)

 

[sedanman]

This page has pictures;
http://www.parkeryamaha.com/helicoil.htm

 

[sedanman]

This page has pictures;
http://www.parkeryamaha.com/helicoil.htm