Stripped threads in valve cover

So I can't finish adjusting my valves, because the threads are stripped where the shoulder bolt sits toward the right outer exhaust (#4?). I can't secure the bucket hold-down tool there, so I can't get the shim out. Do I have to drill this out and retap it? Is there any other way? I don't have anything but a hand-drill, and I'm not super confident with freehand drilling out my engine. Just typing that sentence fills me with dread.

 

Do a forum search for zip tie method. But your still gonna need to fix the thread or the gaskets will leak you you go to install it.

 

Oh yeah, of course. Sorry I should have been more clear: I don't need another way to adjust the valve clearance. I know the stripped threads have to be dealt with, and I was wondering if there was another way to do that? I've heard of back taps and thread chasers and such - should I be looking at those instead? Or is my only option to drill it out, retap it and put a thread insert in there? If so, any advice on doing that? I've only done it once before in an engine block, and it did not go well.

 

First, find a flat bottom tap the same size and thread pitch as the original bolt and try restoring the threads. If that doesn't work, then about the only way is to drill and install a thread insert. It's not very difficult, but it can be intimidating. For peace of mind, make sure the adjacent valve is closed, stuff paper towels all around the offending hole, and soak them with WD-40 which will help to catch the metal shards. I have not had a problem free-hand drilling a new hole for an insert, the old hole will kind of guide the drill bit straight. Go slow, use lots of cutting oil on the drill bit, and you're good to go. For simplicity's sake, buy a thread insert kit instead of buying the pieces separately. It may be more expensive, but having the proper tool and clear written instructions can give you some peace of mind.
Good luck.

 

Yeah what bigshank said be careful and go slow aluminum is very soft (one member on here said our engines are made of an alloy of aluminum and butter) I always try to let the thread lock set up for its full time before putting a load on it. "Save a thread" kits can be gotten pretty cheap from napa and the like.

 

Helicoil is what you need. I've done several of my valve cover bolts.

 

Bigshank's flat bottom tap suggestion worked perfectly. Those threads seemed completely gone, but they're shiny and sharp and brand new now -- and all without drilling/retapping. Cost me about ten bucks and two minutes. That turned out way better than expected. Here's what I learned, for reference: On an '82 Yamaha XJ750R Seca, the valve cover shoulder bolts are M6 x 1, I bought this set (if the link dies, it's Irwin Tools 2727- 3 Piece Set - 6.0 mm - 1.00 mm) and used the 'bottom' tap. Though I could've done it even cheaper and just bought the one. I covered the whole adjacent valve area with Saran Wrap just in case, then turned the tap gently and evenly into the threads, like I was slowly turning in a normal bolt. Once I was sure it wasn't cross-threaded, I just did one turn forward, half turn back until I hit bottom, then did the same while reversing it.

Thanks for the help!

 

We love to hear success stories, congrats!