Broke Cylinder Head Cover Bolt

[vendrizi]

Post valve adjustment I was reattaching the cylinder head cover when I broke one of the 4 bolts holding it on. That bolt broke off in one of the parts that holds the cam shafts (excuse my lack of descriptive terms, see picture).

I ordered new bolts, but what is the best way to remove the broken bolt.

1) Keeping everything on the bike drill/easy out that bolt. Covering everything up with rags.

2) Remove that single piece and drill/easy out. Or if I mess up buy a new one. Can I just remove one of the 4 retainers and reattach it at the given torque (I don't know what that is). Or do I need to remove both the retainers for the intake cams and tighten down together?

3) Something else?

Thanks for any input!

[JohnnyBravo]

Looks like it's drill an easy out time

Is the bottom of the hole open? Maybe you can get it out easier taking it apart... Idk mine is too new to have a valve adjustment yet

[Flying]

Left-handed drill bit.

[Motofool]

Originally Posted by vendrizi

...........Can I just remove one of the 4 retainers and reattach it at the given torque (I don't know what that is)..........

Welcome, James !!!

Do you mean you don't know the value of the specified torque or the meaning of torque?

As those are assembled first and then machined together, that top half matches the bottom half of the journal, reason for which you should avoid replacing only the top half.

If you remove the part, you will need a torque wrench in order to tighten those two bolts.

On the engine or out, that stud should be easy to turn out.
If you are not sure about damaging the aluminum thread, just take the part to a machine shop.

[Cra1g]

The replacement bolt you need is 92153-0793. Just want to make sure because the parts diagram you have pictured isn't the one with the correct bolt in it.

I actually have some spares of these exact bolts if you want one. Just pay for shipping. Probably quicker than most online parts suppliers.

[vendrizi]

I pulled that retainer off the bike and got the broken bolt out. I tried drilling a pilot hole and using an easy out, but the bit kept walking on the uneven break surface. What worked was flipping it over and drilling into the backside, the bolt just unscrewed itself. Fantastic!

My torque reference comes from http://faq.ninja250.org/torque/ex250f/. Its a little unclear what part this is. I think it is a "Camshaft bearing cap bolts" which says 8.8ft lbs and to tighten in the specified sequence. But I'm not sure what that sequence is.

Thanks!

Cra1g: I already ordered those bolts from a local dealership. $5 shipped per bolt... Arriving Wednesday. Thanks for the offer.

[Motofool]

Originally Posted by vendrizi

...........I think it is a "Camshaft bearing cap bolts" which says 8.8ft lbs and to tighten in the specified sequence. But I'm not sure what that sequence is......

Torque for those bolts is correct: 8.7 ft-lb = 104 in-lb = 1.2 Kg-m

The sequence is meant for when the camshaft is removed and replaced.
In your case, 1: bolt closer to spark plug, 2: bolt closer to carbs.

Torque for broken bolt is 8.7 ft-lb = 7.3 in-lb = 1.0 Kg-m