Engine Casing Repair

So, the previous owner of this bike did a number on several of the engine threads around the bike. I was able to fix nearly all of them by rethreading and installing a helicoil. However, one of them was so bad that I have been unable to fix it. As you can see, I tried to use JB weld, tap a hole, and install a helicoil, but it did not go so well. 

My next plan was to use some low temperature aluminum welding rods and a blow torch to fill in the spot and then re-tap or I was thinking of trying the technique at the link below with the same low temp welding rods. This is the cover for the clutch/drive sprocket btw. I have no experience with aluminum welding and have heard it can be difficult if you aren't experienced. It doesn't have to look good. I just has to work. 

Thoughts?



Anyone have any thoughts on the best way to go about this? 

No eBay APP ID and/or Cert ID defined in Kunena configurationsearch ebay for 6mm nut sert
One of many -
 

There is nothing to insert the rivet nut into. 

The sprocket cover bolts holes are open, ream to minimum size, the splines hold the nut in place,
 

wrote:

The sprocket cover bolts holes are open, ream to minimum size, the splines hold the nut in place,



 

I think there's actually a chunk of casting missing.
The only decent fix may be to get it TIG welded.
It would be better if all that awful bodgers mate JB weld was removed to see the real damage and a better solution can then be suggested..
 

Yea, I'll see if I can remove all the JB and get a better picture of the situation. The current picture is probably a little misleading on how bad this is. 

It indeed looks as if part of the casting is missing. TIG welding is the only way I can think of to do a proper repair, replace the missing metal and then machine / dress up the mating faces, tap the threads etc. It's unlikely that this can be done with the engine assembled, it looks like a complete strip down. If that's the case, I'd check what a replacement engine case would cost - might be cheaper, and then you know it's right.

Ian

It’s really hard to find “matching number” Kz bikes after the Z1 run stopped. It’s not as critical to the value of the bike. I agree as mentioned, that buying a set of cases in the correct serial number range would be a more cost affordable way to accomplish your goal.

The 1976 Kz900 engine number range is Z1E086001 - 138846. If you know the month your bike was built you can search for a serial number to get close. 

No eBay APP ID and/or Cert ID defined in Kunena configurationI tried it all. Wound up buying 8mm/6mm inserts thanks to one of our members. Used a m8 helicoil  then used the insert. The hole was getting too big for just the insert.  Works great.
Steve
 
Start at 8:25

Alright, I cleaned the JB weld out. It appears that the previous owner drilled a hole under the hole in question at some point in the past. Strange. I think I'm going to try the low-temp aluminum solder sticks before I do anything else. 

That is really quite fugly,  the result of a repair attempt that just kept going further downhill!  Good luck with your repair attempt,  it can be repaired by a good man with a TIG and some careful reshaping and drilling if all else fails.

Mike

You will need a lot of localised heat in the cases to have a chance with the low temp alloy rods and even then the results won't be great.
I've plenty of experience with it and you will need at least an oxy/acetylene torch to have half a chance to beat the heat soaking and ideally the cases stripped bare.
It runs like piss and building it up to form a structure to shape and match the original case isn't what it's any good at.
With a job like that i would personally get it Tigged.