Thanks for all the replies guys, I really appreciate it. I'm glad there's a relatively easy fix, I'm just still miffed that I've got to pull everything apart again!
You know the helicoil can be done with manifold attached to motor and the head pipe can twist on the loosened coupler out of the way right ?
FYI cylinder to case bolts work great too. OEM Yamaha hardware quality can't be beat. Put a girdle kit on and use the three cylinder bolts for your headpipe.
A long bolt with a nut will work for a temporary (beach) repair for that hole. Or at least until you buy the repair kit.
A long bolt with a nut will work for a temporary (beach) repair for that hole. Or at least until you buy the repair kit.
I've been doing that for at least 3 years. Never had a problem. If you grind down a flange nut just slightly it will hold itself against the surrounding surface while tightening. Actually think it is more secure this way as it sandwiches the manifold and headpipe together at a weak point.
Might as well use a carriage bolt next time.