I never claimed to be a master mechanic. I've had some luck getting old motorcycles to run again, but that doesn't mean I totally understand the whys of everything I do. I just know to do it. Every once in a while, though, I run into a bike that allows me just a bit of confirmation. Maybe I am a bit more skilled than your average novice, or how else could describe the skills of the last guy who worked on this bike?
In prior chronicles of this K0 750 rebuild I have described how this guy used a stock head gasket with an big bore. How he created a shifter out of two tabbed lock washers. I thought was he did was dumb, but I kind of understood why he would do it. Parts cost money. But I'm not even sure what to make of this last discovery.
I was putting on the head tonight. As is my wont, I first put in all the bolts and screw on all the nuts before I even bring anything flush just to make sure everything lines up and to make sure I can find where all of the hardware goes. The stud nuts, no problem. The four 35mm bolts in the middle no problem. The 35mm bolt in the middle of the rear; slid right in. I get to the 90mm bolt in the middle at the front. There's something in the hole. Shoot, I figure, I must have missed some of the polishing compound I used. I get out my 6mm thread cleaner..... Wait a minute, this stuff isn't moving. Pull the head.
He has filled the front hole on the head and the cylinder with silicone. Silicone instead of a bolt.
OK, is this some old-timey performance thing that I have never been exposed to? Are you supposed to fill some bolt holes with silicone when you put in a big bore? Can you fill any holes you want, or is there a prescribed regimen? Doesn't removing a bolt and replacing it with silicone kind of alter the engineering?
Jeesh....
By the way, I cleaned out the silicone and the threads are fine, so it isn't that.
Patrick
