How bad of an idea would it be to ride with a missing valve cover bolt? I ask because one of the bolts was broken off into the block. I've tried for hours to get it out and have had no success.

 

Short term you might get by.

Long term, I would be concerned with the cover warping, at sustained,
high-temp riding. It might make a difference where in the pattern, the broken bolt is.

Hopefully, Demon, Conrice, IDoDirt, or one of the other gurus,
can give a more definitive answer.

Personally, I wouldn't take the chance. If it were my bike, I'd drill it.

Start with a small bit, to get a good indexed square hole in the bolt.
Gradually increase the size, till you're almost removing threads.
Use an extractor to back out what's left.
Re-tap the hole, with a blind/bottom tap, to clean the threads.
Use grease with the tap!! Clean up with solvent, finally blow it out with compressed air.

Then, re-install the cover with the replacement bolt.

If you take your time, it's not a particularly, difficult task.

Hope this helps, Ern

 

Thank you for the reply! I've tried drilling but can't get to bite. Broken piece has rounded head. Drill bit walks ALL over.

I just need it to ride to the stealership so I can have them deal with the problem.

 

Do you have enough sticking out to get vise grips on it?

Otherwise, to drill it you will need to file a flat surface to drill on. Then center punch a spot in the center to help the bit stay centered. Start small and go slow until you get to the correct size for a screw extractor.

If an extractor doesn't do it, keep drilling until you get all the bolt out and run a tap to clean up the threads or keep going a little bigger and install a helicoil.

 

Unfortunately, not out enough for vise grips. How would I go about filing a flat surface?

 

Use a flat file and file the top until its flat enough so you can punch a center mark.

Where is the broken bolt located? Center or corner? If its a center, I'd run without it and see if it leaks or not.

 

This is probably a dumb question, but where would I be able to buy a flat file? Would I be able to file it no problem even though it's recessed?

 

Flat files can be bought a Home depot.

Recessed? I thought you said some of it was sticking out. My bad.

Picture time!

 

Here it is!

 

Punch a good center mark and see if you can get the bit to stay in the center.

Otherwise, you may need to remove the head and see if a machine shop can get it out. If you damage the area around the hole too much, the head will be ruined.