Stripped Exhaust Threads

Go with the 8mm studs just like the factory. Should be plenty left to tap if it was a 6mm hole that stripped. Should be able to do everything right on the bike too. Good luck and keep us posted - with pictures!

I was wondering about studs. Do studs make it easier or harder to install the exhaust? The last time I did it was a pain even with 2 people. The rubber band trick and grease on gasket was a miracle though.

I think the studs are MUCH easier. I think slipping the collar over the studs is much easier than trying to get everything lined up and then a bolt through and started into the threads. You'll be happier with the studs for sure. You might want to buy the nuts too if Z1 carries them.

Trick to hold the copper gaskets in place I learned from crusty ole Plummen...

Permatex Copper... coat the flat side of the copper gasket with some permatex, insert into place... They will bond and hold while your inserting your split collars and collars!

This also acts as a sealer of sorts, no exhaust leaks!

See, we all new why we put up with his crap for something... :laugh: :laugh: :laugh:

Or wheel bearing grease - just dab some on the gaskets.

Here is a picture of the exhaust threads. Is this enough material that I would be safe to convert to 8mm exhaust studs? farm3.static.flickr.com/2487/3793526788_7997a03645.jpg

The exhaust collars will have to be drilled for 8mm studs. Be careful to not go any deeper in the engine when drilling and tapping for the 8mm studs. I understand an oil gallery is right behind where the studs go.

I believe a 7mm drill bit is the correct size for the 8mm tapped hole for the studs. Your tap should be a 8 x 1.25 in size. A drill stop should be used to prevent drilling too deep. Using a fixture or drill bushing will keep the tap at 90 degree angle to the engine.

If you don't feel confident in doing the drilling and tapping,I'd suggest calling the bike shops and see who they use for this kind of repair.

Here's a link to a chart (hopefully correct) but MFolks is right, 6.9mm to be exact.

www.boltdepot.com/fastener-information/M...-Tap-Drill-Size.aspx

Ok looks like I will tackle this during the winter. To much good weather to take motor off of bike right now! Thanks for the info.

I've done the drill and tap to 8mm fix many times, and if you are careful and take your time, you can do it with the motor in the bike. Just stuff rags in the exhaust ports and use lots of cutting oil.

Yeah it is tempting to get it out of the way right now but I do not want to have to be "extra" careful because I tend to screw something up. I think I will do the easier way and not have to worry about it so much. So far no exhaust leak has occured so I am not in a big rush.

The plus side to removing the engine is I get to degrease it and also get to repaint frame.