OK, Here's the deal. I have a stripped engine mount where the right frame slider attaches on my 2002 CBR 954. Here are the choices I've come up with and would like some feedback
- It's totally stripped so there's no chance of using a longer bolt
- I could possibly drill through the engine mount and attach a nut on the inside to secure the bolt. This is problematic as the back side of the engine mount is rounded, not flat, so it would be a bit of a hack.
- I could use a helicoil or timecert but that requires dropping the engine. The bike is pretty old with high miles. I use it around town and at the track cause I don't stress about crashing. It's a solid bike and generally performs well but it's not worth a big investment.
- This idea might be original. Rather than drop the engine, what about drilling out the frame mount hole large enough to install a helicoil or timecert in the engine mount. The use a steel sleeve in the frame mount hole to give it a little extra strength. That would save me from dropping the engine.

Would I risk the frame mount hole breaking under hard riding? Has anyone tried this? Does anyone think it's possible?

 

I wouldnt drill out the frame. Frames are built as light as possible and any weakening of the frame can have bad consequences. Even if you put a steel insert in place of the drilled out hole in the frame, the frame itself is still weakened. The steel insert will do nothing for adding strength to the frame. Plus, unless you can machine the hole in the frame, the chances of getting the hole straight with a handheld drill is very unlikely. You will end up with an egg shaped hole, not something a steel insert will press into, or give any type of support. Even if you use a reamer to smooth out the drilled hole and to create the proper size hole for your steel insert, the chances of the hole still being straight across and inline with the engine hole will be very unlikley, so you may run the risk of putting stress on the bolt, engine, or frame from the bolt not lining up correctly.

I've never used a timecert, but have used keyserts with great success. They are solid one piece inserts that have keyway on the side of them. Once you have the keysert to the depth you want, you drive the keys down and it removes the threads from the mounting hole, which in turn locks the keysert in place. Heli-coils tend to back out, and for an aluminum engine that will see high vibration, I would steer clear of the heli-coil.

In all honesty, the time and effort to drill and ream out the frame's hole, and place a steel insert in the frame will take just as long, if not longer, than simply dropping a few bolts to lower the engine enough to put in a keysert or timecert.

I'd lower the engine and put in a keysert myself. Oh, if you use the keysert, you don't need to have the special tools to install them. You can thread them in by hand, then use a punch to drive the keys down.

 

You're right of course. I wanted a shortcut but I know better. I just needed to hear it from someone else. Thanks for the sound advice.