Broken case threads

[shuttlec0ck]

Hello,

While tightening down the inner cases to 8ft-lb (manual says 15ft-lbs) I managed to strip the threads off 2 bolts on the case. Need some recommendations, this is what I'm thinking, re-tap the hole same width and pitch and see if can work, drill to next size 7mmx1.0, or drill to 3/8 and install a 6mm anchor and use the same bolts.. Feel like a dolt right now, btw it's a crf250r 2004

Thanks[emoji106]

[418Stroker]

Hello,

While tightening down the inner cases to 8ft-lb (manual says 15ft-lbs) I managed to strip the threads off 2 bolts on the case. Need some recommendations, this is what I'm thinking, re-tap the hole same width and pitch and see if can work, drill to next size 7mmx1.0, or drill to 3/8 and install a 6mm anchor and use the same bolts.. Feel like a dolt right now, btw it's a crf250r 2004

Thanks[emoji106]

Did you use 1/4" drive inch lbs wrench? I had this happen to me on a small fastner in the past and just tightened the remander of them by hand.

[shuttlec0ck]

I hand tighten the bolts with a 1/4 T wrench first, then tried to verify the torque with a 3/8 torque wrench.. 15lbs seemed way to high, so I thought i was safe at 8lbs but apparently not

[William1]

Time-Sert or HeliCoil.

 

Wrench range should of been between 0 and 30 ft-lbs (or better, just 20) to be accurate at that low a setting.

[justaskmenicley]

Use a dremel with a cutting wheel and cut a slot in the head, then use a straight screw driver to get them out.

[mossman77]

While tightening down the inner cases to 8ft-lb (manual says 15ft-lbs)

 

 

Can you cite where in the manual it says 15 ft-lbs?  I just rebuilt a 250R bottom end and didn't see a torque spec in the respective chapter.  I tightened them to 7 ft-lbs, which is the value indicated in the standard torque specifications in chapter 1 for 6mm bolt/8mm head with small flange.

 

Edited September 26, 2016 by mossman77

[shuttlec0ck]

Don't even try it, hand tight and you're good to go..

[mossman77]

Don't even try it, hand tight and you're good to go..?IMG_1474911494.525307.jpg

 

Dude, that's the torque spec for the transmission drain bolt, not the case bolts!  The manual says to tighten the case bolts in a criss cross pattern then torque down the transmission drain bolt.

 

Edited September 26, 2016 by mossman77

[shuttlec0ck]

Well that makes more sense. That picture on the right can be deceiving, lol.

[mossman77]

Don't worry about it. I installed the piston backwards initially so we all make stupid mistake. Hope you get it resolved.