Husqvarna 562XP spark plug tightening torque question

[Joab]

My workshop manual (i.e. one I downloaded) indicates that the correct tightening torque for the spark plug on a 562XP is 18-20Nm. That's 159-177 inch-lbs -- and it would seem to be around the normal range for a 14mm threaded spark plug, but it seems really high for a little 10mm thread spark plug like the CMR6H that the 562XP uses.

Does anybody know if the 18-20Nm is actually correct? Or is that a misprint?

 

[holeycow]

Never torqued a spark plug in my life. Snug it up and a tiny bit more. A tiny bit..

Only had one loose plug in 1977 that actually blew out of a dirt bike. The bike was brand new and on its second break-in ride. The factory didn’t snug up the plug properly. I just put another plug in and carried on. It never happened again.

Most mechanics torque most bolts by feel. A torque wrench can help you learn the feel.

I’ve broken as many bolts with a torque wrench as without.

What if the threads are dry? Or oily? Or greased? Or antisiezed? Or loctited? Or dirty? Those conditions all affect the reading of the torque wrench.

You can feel the microscopic stretch in most small bolts.

Anyway, spark plugs don’t need a torque wrench, IMO.

 

[Joab]

Never torqued a spark plug in my life. Snug it up and a tiny bit more. A tiny bit..

Only had one loose plug in 1977 that actually blew out of a dirt bike. The bike was brand new and on its second break-in ride. The factory didn’t snug up the plug properly. I just put another plug in and carried on. It never happened again.

Most mechanics torque most bolts by feel. A torque wrench can help you learn the feel.

I’ve broken as many bolts with a torque wrench as without.

What if the threads are dry? Or oily? Or greased? Or antisiezed? Or loctited? Or dirty? Those conditions all affect the reading of the torque wrench.

You can feel the microscopic stretch in most small bolts.

Anyway, spark plugs don’t need a torque wrench, IMO.

If I'm working on my bench and I have a torque spec available, I will often use a torque wrench. The rest of the time I go hand tight and up to about 1/16 of a turn more by feel.

I haven't had issue with either method, but I suspect you are right that the turn of nut by feel method is more reliable.

In the case of my 562, I don't use a torque wrench because the torque spec available seems wrong.

It's more curiosity than need, but I'm wondering if there was a service addendum on that manual.



Sent from my Moto G (5) using Tapatalk

 

[CR888]

A torque wrench is not the best idea for tightening down spark plugs. The threads on a new cylinder and plug are dry/clean while threads & plug on a used saw will be oily. Feel is what needs to be learned, not numbers in a text book.

 

[HarleyT]

Stihl spec

Spark plug IS-M10x1 Spark plug 9.0

 

[holeycow]

If I'm working on my bench and I have a torque spec available, I will often use a torque wrench. The rest of the time I go hand tight and up to about 1/16 of a turn more by feel.

I haven't had issue with either method, but I suspect you are right that the turn of nut by feel method is more reliable.

In the case of my 562, I don't use a torque wrench because the torque spec available seems wrong.

It's more curiosity than need, but I'm wondering if there was a service addendum on that manual.



Sent from my Moto G (5) using Tapatalk[/QUOTE


I didn't mean that "feel" is more reliable. I suppose I meant that it is just as important to learn the "feel" of a torque wrench. And not even all torque wrenches "feel" the same. I have cheap torque wrenches (good ones cost way too much for an amateur...or at least this one), so I don't necessarily trust them all of the time. Mine are "clickers". I don't know where my torque-bar torque wrench disappeared too. It was a more reliable tool.

a little practice is all

and even the best will continue to break **** from time to time. Slowly but surely we break less and less ****, but then eventually we do.

 

[HarleyT]

I have known a few guys that need a torque wrench, they just had no "feel", and would break off small fasteners, I am sure some therapy might help them, but who knows.

 

[Joab]

As a follow up to this thread. . . I'm spending a lot more time than usual working on saw projects while we're under Covid 19 lockdown. Along the way I came across an updated service manual for a 562xp. I noticed there were 3 or 4 fastener torque spec corrections -- so it made me feel pretty confident that somebody was paying attention when they published the revisions. 18-20 Nm was still what was listed for the spark plug -- apparently it's not a typo.

I can report that I subsequently pulled out my plug, gave it wipe with a rag and a mild degreaser (i.e. Windex), and put it back in torquing to 18 Nm. . . No issue whatsoever.

( I do tend to overthink things. On that note, I'll also note that I double-checked the calibration on my torque wrench before doing this.)

 

[Mad Professor]

As a follow up to this thread. . . I'm spending a lot more time than usual working on saw projects while we're under Covid 19 lockdown. Along the way I came across an updated service manual for a 562xp. I noticed there were 3 or 4 fastener torque spec corrections -- so it made me feel pretty confident that somebody was paying attention when they published the revisions. 18-20 Nm was still what was listed for the spark plug -- apparently it's not a typo.

I can report that I subsequently pulled out my plug, gave it wipe with a rag and a mild degreaser (i.e. Windex), and put it back in torquing to 18 Nm. . . No issue whatsoever.

( I do tend to overthink things. On that note, I'll also note that I double-checked the calibration on my torque wrench before doing this.)

I give plugs a wipe with never-seize

 

[Joab]

I give plugs a wipe with never-seize

It's probably a good practice -- although I'd reduce the torque due to the lubricating effect or just stick with 1/12 past finger tight.

In theory, if you use the factory spec plug (NGK CMR6H) the plating on the plug has some no-seize effect. It's still probably not as good as never-seize.

 

[rupedoggy]

Wow an anal Kunuckyen.

 

[RED-85-Z51]

Ive installed plugs with a 1/4 impact...or a wrench...whatever is closer[emoji1][emoji1][emoji23]

Sent from my LM-G820 using Tapatalk

 

[Joab]

Wow an anal Kunuckyen.

They do exist.

 

[Joab]

Ive installed plugs with a 1/4 impact...or a wrench...whatever is closer[emoji1][emoji1][emoji23]

Sent from my LM-G820 using Tapatalk

 

[Bob Hedgecutter]

Way I see it- the chainsaw companies supply a spanner with the new saw that enables the new owner to remove/replace the spark plug- no torque setting involved.
I guess if you swing on that enough to bend the handle/driver blade- you might be a wee tad tight.

New plugs need a bit more of a tweak to set the crush washer- or run a wee bit and tightened up if needed, other than that, a scrench does just right- tight feeling is tight enough.
Works for me- but anyone else can do what they feel they need to tickle their fancy.