Stripped bolt - help a noob

One of the bolt holes that secures the sprocket cover on my '79 KZ750 is stripped. It's not the bolt, but the threads in the hole in the engine block.

It's normally held in place with a 6M x 90mm hex head bolt. Is my only option to drill and tap this for an 8M bolt?

There's a big difference between a 6M and an 8M and I'm not really sure an 8M will fit in the sprocket cover.

Do they make 7M bolts? I've never seen one.

Or, can I fill the hole with something like JBweld and then drill and tap new 6M threads in there?

Helicoil ?? Might be a easy fix

I could swear my exhaust studs are a 7mm thread. I know for sure that I have a 7mm tap, so surely bolts exist to go with it.

I would take it to a machinist and have them install a timesert or helicoil. Ed

www.timesert.com/

Is a helicoil or timesert kit the sort of thing a noob can DIY or do I really need to go to a pro for something like this?

I'd pay the money and have someone with the tools and experiance repair the stripped threads. It's real easy to make matters worse if you really don't have any idea on how to fix this.

You'd need the proper size drill bit, making sure to be 90 degrees to the surface when drilled,the correct size heli-coil or timesert, and then be able to install it the correct way...

In practice, they aren't hard, but you'd have to get the tools for it, would be cheaper to just take in unless it's something you plan on doing a lot in the future. It's a pretty easy procedure, they shouldn't charge much for it.

You can surely youtube how to install helicoils and timeserts. I know I've seen videos of both before.

lHelicoil is a good option go slightly bigger or switch to SAE? (Check your bolt at hardware store thread checker for your best suiter)

Also if you really want to do it the right way get a stud (Threaded rod no head) and some red lock tight.

Put locktight on the threads put it in the hole, wait till it cures and put a nut on the outside and tourqe down!

If Locktight wont hold and you feel like being an A$$ hole JB weld the stud in there and really champ it up!

It is not that hard to tap new threads, just get a good kit MAC or Snapon or buy only the size you need.

Depends on just how much of a noob you consider yourself, it won't cost much to have it done, maybe find a guy willing to teach you the ways.