Proper Torque

[mbac31]

I cant seem to find my manual for that motor. Someone here has to know. I was wondering what the proper torque is for the plugs on a 2005 - 175 Optimax. I need to change the plugs tonight.

 

Thanks

[lowerunit]

I cant seem to find my manual for that motor. Someone here has to know. I was wondering what the proper torque is for the plugs on a 2005 - 175 Optimax. I need to change the plugs tonight.

 

Thanks

My 150 Opti calls for 20 lb. ft or 27N-m dont know if that helps.

[Roy]

Mercury manual says finger tight then go to 20 ft lbs.

[Roy]

You beat me to it Lowerunit.

[mbac31]

Thank you Gentle Men and Roy

[Roy]

Gee thanks smallie....just wait till the next time you need to know about torque.

[Billy Bob]

39 years of installing plugs in various types of motors and I never used a torque wrench....Huh....

 

Guess I been lucky.....

[Tybo]

Gap less plugs their BB.So you need to torque to achieve the right gap between

the top of the piston to the electron.Gap less is also one shot deal.

With the torque washer being crush to the right gap the first time.

The second time will move the electron closer to the piston. Making a shorter spark.

In most cases it will not affect the power,but the wrong gap will affect fuel consumption.

With the wrong gap the ECM will keep adjusting fuel flow so the desired RPM are matched.

[JohnF]

Gap less plugs their BB.So you need to torque to achieve the right gap between

the top of the piston to the electron.Gap less is also one shot deal.

With the torque washer being crush to the right gap the first time.

The second time will move the electron closer to the piston. Making a shorter spark.

In most cases it will not affect the power,but the wrong gap will affect fuel consumption.

With the wrong gap the ECM will keep adjusting fuel flow so the desired RPM are matched.

 

Interesting point. I've never heard anything about those tolerances being so critical before but then most of my engine work was pre-1975. I know engine build tolerances and gaps were getting much smaller even then so it doesn't surprise me that plug torque and the crush effect have come into play. Like others have said I don't think I ever used a torque wrench for plugs, new or otherwise. I was forever pulling the plugs in my two strokes checking the fuel mixture settings.

 

JF