2009 EC 450F head bolt torque settings

[mikeb01]

Hi there fellow GasGas riders,

I have a 2009 EC450F, and am going through a top and bottom engine rebuild. I am slowly putting things back together but when it comes to the cylinder head bolt torque settings I am feeling a bit nervous.

I have searched here as best I can, and the torque table on this site lists 25Nm for cylinder head bolts, but I think this spec is for the 2 strokes?

The 2005 workshop manual lists 4.5kg (presumably kg/m which is 44Nm) as the torque, but there are many posts on this site saying the torque values in the manuals are not to be trusted.

So what settings do I use?

I looked at the DRZ400 specs as there are apparently some similarities between the motors (DRZ spec is 46Nm) but TT forum says the DRZ manual specs are not to be trusted either and to instead use 43 ft lbs (58Nm).

I also looked at older WR450 specs and they have a specific procedure for tightening the cylinder bolts (torque the cylinder head bolts to 20 ft lbs, then loosen and re-lube the bolt threads, then torque to 14 ft lbs, then turn each bolt 90 degrees, then another 90 degrees for a total of 180 degrees (one half turn)).

I could flip a coin and pic a spec, but I think I only get one chance at crushing the head gasket (which cost me close to $200 AUD - ouch).

Any helpful suggestions or GasGas wisdom from a guru would be greatly appreciated!

Thanks very much

Mike