I've removed the AIS gear from my '02 R1 engine, currently the 4 ports above the exhaust ports are open to the air.
The holes look to be about M8 in size but my tap doesn't seem to want to know anything about cutting a thread in them. I don't have access
to any welding stuff to be able to seal the pipes up.
I was thinking of cutting the pipes and using something like liquid metal to seal them, before I start butchering can anyone offer other ideas?
Have a look here.
You don't need to remove it.....
I know I don't need to remove it, but it's extra weight and with it gone it's much cleaner around there, plus it's another couple
of pounds I don't have to lose
Fair comment! 
Yamaha supply the plugs in their R1 race kit.
The other option is to tap the stubs and plug them with a bolt, but they're made from a very hard material.
Have a look here under 'Engine Preparation'.
Have a look here at the YEC parts list and prices. A set of four AIS plugs works out at 30-odd quid....
I have just tapped the AIS ports on a Fazer 1000 using a brand new high quality M8 taper (No 2) tap. Threads cut OK, though it was tight. That said,
I was using copper grease instead of cutting compound and breaking off the swarf more regularly than usual. The ports are sealed with stainless
button heads but I may need to add some copper crush washers for sealing.
Failing that, how about using a 5/16" tap?
Good luck,
Dom.
quote:
Originally posted by another_dom
high quality M8 taper (No 2) tap