Torque Settings

[bignico2411]

Getting the scoot out of hibernation this week and I'm going to give it some TLC before going back on the road. One of the things I intend to do is clean the top end, but I'm confused re torque settings for the cylinder head. Every list/chart I've seen shows the settings in a range, but where to I set the wrench? Halfway between min and max? I apologise if this is a particularly stupid question but I've never actually used a torque wrench before!

Cheers

[mijapxman]

Bignico2411, not sure if I'm understanding you correctly, so I'll tell you the way I tighten a cylinder head, ( others my do it differently ).

Say my head was to be tightened to 16Nm , I would tighten the head hand tight with an ordinary socket and ratchet,diagonally as shown in the Haynes manual, then I would set my torque wrench to (say) 8Nm and tighten the first nut, till the torque wrench clicked ONCE, then move to the second nut (diagonally) tighten it to 8Nm and so on, till all 4 nuts were tightened to 8Nm,

Next, I would set the torque wrench to (say) 12Nm and tighten all 4 nuts in the same diagonal pattern to 12Nm.

Next I would set the torque wrench to 16 Nm ( the final number) and do the same diagonal sequence and that's job done.☺

Some people may do it in 2 stages, (say) 10Nm then 16Nm, either way, the object of doing this is not to warp

Or break anything.

Three important things to remember are: hold the torque wrench at it's grip ( holding anywhere else will give a false reading). DO NOT hold at the very end of the grip !!!

Only tighten till you hear it click once, any more and you are over tightening the nut.

Once you are Finished with the torque wrench, reset it to Zero + a baw (ball) hair,( or whatever your instructions say) to keep it calibrated properly, whilst not in use.

All of the above relates to NON digital torque wrenches.

Hope that's some help.☺

Jim ( mij)😀

[bignico2411]

Jim, that is very useful info, thank you. Take a look at this link, though, here's where my confusion lies. For a standard PX125 cylinder head, the setting is 9.5-13 foot pounds. To my mind, that's a range. So where in the range do I go for? 

[mijapxman]

I think it's because some torque wrenches are more accurate ( and expensive) than others, one of mine says plus or minus 2% accuracy, the other ( from memory) says +/- 3 or 4% ( machine mart low torque one) £22- £27 I think?

In the example you give, I would use 13 foot pounds , I tend to always use the higher number. Starting at 7 foot pounds then 10, then 13.

I should add, I think it's very important to properly torque alloy barrels as best practice.

Hope that makes sense.😉

Jim

[mijapxman]

A good site for tips is Delboy's Garage, search moonfleet41 on YouTube.

It's a bike site but Delboy and his Mrs, Penny are worth a look.

He does a few simple skills vids about using tools etc, that are interesting.

I like the sheet metal work he shows how to do, as you can apply it to our metal bodied frames!

Cheers

Jim ( mij)☺

[bignico2411]

Apr 3, 2017 21:16:47 GMT mijapxman said:

I think it's because some torque wrenches are more accurate ( and expensive) than others, one of mine says plus or minus 2% accuracy, the other ( from memory) says +/- 3 or 4% ( machine mart low torque one) £22- £27 I think?

In the example you give, I would use 13 foot pounds , I tend to always use the higher number. Starting at 7 foot pounds then 10, then 13.

I should add, I think it's very important to properly torque alloy barrels as best practice.

Hope that makes sense.😉

Jim

That makes perfect sense, Jim, thank you. I was inclined to go for the higher number, but felt it best to ask those who know better. And cheers for the heads up on Delboy's Garage, I'll have a look for that later.