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Spark Plug Installation - Torque Specs

#1

S

SuperCuts

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.


#2

B

bertsmobile1

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


#3

StarTech

StarTech

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.


#4

Hammermechanicman

Hammermechanicman

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.


#5

StarTech

StarTech

Maye this will clear this up...As 27 nM is not that bad depending the plug thread size.

1679923790492.png


#6

R

ride2nite

SuperCuts said:
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.
Click to expand...
Seat by hand and 1/4 turn for new, 1/8 turn for used.


#7

S

SuperCuts

OK. Thanks for the help everyone. Good info.


#8

Tiger Small Engine

Tiger Small Engine

SuperCuts said:
OK. Thanks for the help everyone. Good info.
Click to expand...
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.


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