Exhaust bolts - reassembly

[Yar786]

I was doing an engine swap on my xb9r and had a nightmare of a situation where a stripped out exhaust bolt wouldn't come out. After many attempts I'm just going to swap the rocker box assembly from the old engine and put it on the newer engine as long as they match up. Should work right?

But my biggest thing after this is how much do you tighten down the bolts? Does the header pipe sit in the way in the gasket? I'm afraid I may have another bolt snap. 90% of my project has been spend dealing with the exhaust ports. These no videos just manual says tigthen down until its flush but some people say dont over tighten it.

 

[Cooter]

Aktuully the manual says this:

and this:


Clean all the threads, thread chaser... NOT a tap! Install stud to bottom, hand tight, and torque header nuts to that value. IMO, get new studs and new nuts.

 

[34nineteen]

If your going to remove the rocker box, just remove the head, take to a machine shop and have them remove the broken stud. Its 4 more bolts. Remember, new heads are non-existant, and used heads are very hard to come by and expensive when they do come up for sale. So, if you f this up further, you may junk the head or require a much more expensive fix at a machine shop.


The stock torque value of the exhaust nuts is just enough to crush the gasket to make the seal confirm. If they didnt specify that, people would just tighten them down until the flange bottomed on the head and/or the studs break.

And, you will want to find out why the stud broke in the first place. Check the exhaust hanger bushing in the front of the case for looseness, because if it is, you will be doing this again sooner than later. Oversize bushings are available from Twin Motorcycles.

 

[Cooter]

You're an oversize bushing.

 

[Yar786]

Thanks for your help folks. Got the rocker box and header pipe back in without breaking any bolts.

 

[Cooter]

Awesome! Glad you got that done

 

[34nineteen]

Congrats.