Spark Plug Installation - Torque Specs

SuperCuts

Forum Newbie
Joined
Mar 26, 2023
Threads
2
Messages
3
Hello Everyone,

Probably a stupid question but I will post it anyway...
I changed the plugs in my John Deere Walkbehind (61 inch with Kawasaki Engine). I removed the original plugs (from the factory) using my digital torque wrench. It took 14.2 Nm of torque to loosen them.

The JD maintenance book calls for the plugs to be torqued to 27 Nm. As I installed the new plugs, I used the good digital torque wrench using the old fashion get the plug tight and turn 1/4 more. Using this method, I noted the torque on the wrench was around 15 Nm (no were near the 27 Nm called for in the book).

Since the old fashion way got me close to the torque that was required to break the plugs free, I am really concerned with trying to get to 27 Nm...It seems like they would be way over torqued....

I have changed a lot of plugs over the years. I have never seen this kind of discrepancy. Should the break away torque and the tightening torque be similar in this case (since the original plugs are from the factory)? Since the plugs are tight and it runs fine, does anyone think I should try to get to the 27 Nm?

Kinda of stupid I know...again, my only concern is the great discrepancy between the factory spec and where I felt comfortable. . .

Thanks for any thoughts.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
The calculator generation who only understand numbers in place of what the numbers actually mean can not fart without a number for it.
Finger tight + 1/4 turn if fine .We know that all that is required is some crush on the sealing washer
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
75
Messages
10,113
With sealing ring per NGK. Taper seat has a different spec.

1679917668412.png
Now of course this for new plugs, older used plugs it is as Bert suggests as the sealing washer is already crushed.
 
Last edited:

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
49
Messages
3,485
27Nm is high for a plug with a crush washer. That is more like a taper seat plug in an iron head. I am with bert. 1/4 turn after finger tight.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
75
Messages
10,113
Maye this will clear this up...As 27 nM is not that bad depending the plug thread size.

1679923790492.png
 

ride2nite

Forum Newbie
Joined
May 28, 2014
Threads
0
Messages
3
Hello Everyone,

Probably a stupid question but I will post it anyway...
I changed the plugs in my John Deere Walkbehind (61 inch with Kawasaki Engine). I removed the original plugs (from the factory) using my digital torque wrench. It took 14.2 Nm of torque to loosen them.

The JD maintenance book calls for the plugs to be torqued to 27 Nm. As I installed the new plugs, I used the good digital torque wrench using the old fashion get the plug tight and turn 1/4 more. Using this method, I noted the torque on the wrench was around 15 Nm (no were near the 27 Nm called for in the book).

Since the old fashion way got me close to the torque that was required to break the plugs free, I am really concerned with trying to get to 27 Nm...It seems like they would be way over torqued....

I have changed a lot of plugs over the years. I have never seen this kind of discrepancy. Should the break away torque and the tightening torque be similar in this case (since the original plugs are from the factory)? Since the plugs are tight and it runs fine, does anyone think I should try to get to the 27 Nm?

Kinda of stupid I know...again, my only concern is the great discrepancy between the factory spec and where I felt comfortable. . .

Thanks for any thoughts.
Seat by hand and 1/4 turn for new, 1/8 turn for used.
 

SuperCuts

Forum Newbie
Joined
Mar 26, 2023
Threads
2
Messages
3
OK. Thanks for the help everyone. Good info.
 

Tiger Small Engine

Well-Known Member
Joined
Dec 7, 2022
Threads
1
Messages
646
OK. Thanks for the help everyone. Good info.
Most of the spark plugs on my customer’s mowers are not tight enough. It is almost like people are afraid to strip them out. 15-20 foot pounds of torque for most plugs. I just go by feel.
 
Top