Stihl 462 problems

[k.chandler23]

A friend of mine has a Stihl 462 that has blown the spark plug out of two different cylinders. We replaced the first with an OEM used cylinder just for it to do it again 4 months later. Has anyone else seen this issue with the 462s? Or is there a reason this saw is building that much compression?

 

[ballisticdoughnut]

Not tightening the spark plug tight enough. Seen it happen many times.

 

[k.chandler23]

Not tightening the spark plug tight enough. Seen it happen many times.

I'm not saying that's not the problem here but i just don't believe that he's left it loose twice.

 

[ballisticdoughnut]

I'm not saying that's not the problem here but i just don't believe that he's left it loose twice.

On a new plug you have to crush the washer, otherwise it will eventually come loose and that’s when they blow out. I can get a torque spec tomorrow at work but I tighten them until the washer crushes and go a little further so it’s tight. You don’t wanna crank the S out of it but it does have to be fairly snug.

 

[k.chandler23]

On a new plug you have to crush the washer, otherwise it will eventually come loose and that’s when they blow out. I can get a torque spec tomorrow at work but I tighten them until the washer crushes and go a little further so it’s tight. You don’t wanna crank the S out of it but it does have to be fairly snug.

Thanks for the replies. Have you ever seen a helicoil fix one? He's looking at that route or a 500i lol

 

[ballisticdoughnut]

Thanks for the replies. Have you ever seen a helicoil fix one? He's looking at that route or a 500i lol

Yeah I’ve fixed many with either a helicoil or timesert.

 

[k.chandler23]

Yeah I’ve fixed many with either a helicoil or timesert.

Thank you

 

[Seachaser]

If it’s the threads, this tool may help

 

[stihltech]

Nope, it ain't the threads, it is the lack there of.
I can't count the number of plugs that I can take out with my fingers when they come into the shop. Usually prefaced by " It doesn't run right (or it wont start) and I just replaced the plug.
Not only is it hard on the threads, hard to get a good ground.
Crush washer must be crushed. Taper seat plug snug and 1/16th turn (from 1975 Auto Service Specialist course at Alfred).
They made us torque sparkplugs. When asked why, they answered"You will always know what tight is and won't break or strip one". Worked well ever since.

 

[altatim]

12Nm torque spec from Stihl. Can agree that it takes a few turns to set a new crush washer. I've never had one back out on me.

 

[k.chandler23]

Nope, it ain't he threads, it is the lack there of.
I can't count the number of plugs that I can take out with my fingers when they come into the shop. Usually prefaced by " It doesn't run right (or it wont start) and I just replaced the plug.
Not only is it hard on the threads, hard to get a good ground.
Crush washer must be crushed. Taper seat plug snug and 1/16th turn (from 1975 Auto Service Specialist course at Alfred).
They made us torque sparkplugs. When asked why, they answered"You will always know what tight is and won't break or strip one". Worked well ever since.

What is the thread pitch on the 10mm plugs?

 

[64poncho]

M10 x 1

 

[k.chandler23]

M10 x 1

Thank you