I am crying and swearing... I was putting head on the cylinder. There are 4 alien M10 screws of 46Nm and two M6 screws of 12Nm. These M6 are in camchain duct. Was tightening them up to specs (12Nm) and screw seat cracks. Why - is the manual wrong and torque is less than 12Nm???? I have Snapon torque wrench. Will send it today for recalibration. However what to do with the head? Get one from wrecker? Would KLX300 one fit KLX250S 2009? Suggestions please!!!!

 

That's a little over 8ft/lbs - sounds right to me. Do you have a pic of the crack? I'm not sure how concerned I would be on that side of the combustion chamber. Those two bolts don't really have much to do with sealing the combustion chamber. Do you still have the head torqued, or did you remove it?

 

I removed only M6 bolts. Head is torqued. Crack is big enough to worry me - small parts can fall down. I am going to unbolt it now and take pictures.

 

There u go.... by the way, heads are sold as assembly. If I gonna get one from wrecker should I care about the cams or not?

 

Do you mean just grind what was snapped off and dont use M6s???? Is it good idea?

 

you can have that welded at a shop and re drill / face the bolt surface.
Shouldn't be too costly.

 

Wow - Not quite what i was expecting. Doesn't look like you have enough material to mill it down and use a shorter bolt. Welding may be your best option.

 

+3

Had it been a simple crack like i was envisioning i would have just jb welded it up and got on with life, that side of the head really wouldn't be under a great amount of stress IMO, but a huge *** blow out like that needs some proper welding action and most likely re-tapped for a larger bolt.

 

Daaaang. You must have had that on yard/lbs!

Good luck.

 

I am not sure if rewelding is the cheapest solution down here. It could cost as much as a head from the wrecker. What do u mean - re-tapping for larger bolt - they screw in into crankcase. Gonna check my options. At he moment head from US is $670 plus postage ($50/$100 more). Local bandits offer for $870. Didn check wreckers or workshops yet...