So, most threads of this sort are either instructive or informative. This thread will likely be neither, unless my gross incompetence is instructive or entertaining to others attempting the same thing. It could happen, I guess. My one goal with this thread is to screw something up horribly in each installment, hopefully in an entertaining fashion.
I have a 750K3 frame with a K6 engine. Its all well and fine, but its weeping oil left and right, so its time to dig in. It runs fine, though its always had a slight misfire and pop upon downshifting. A spark plug is stuck in the cylinder head, so it needs a helicoil. Also, the PO told me it had a "boring-out, so its really big!" kit in it. Always wondered about that. After owning this bike for three and a half years, I am damn curious to crack open the engine and see what is the what.
First things first, I have to actually remove the engine. To this end, I host a garage night for the Chicago Vintage Motorcycle group. In exchange for cheap beer and decent pizza, they ride their real and valuable and nicer-than-my-bike motorcycles to our alley and generally make a nuisance of themselves. A few of them then actually help me hoist my 175 lb. lump of engine out of the frame, thus starting this fabulous journey.
Its surprisingly easy, disconnecting all the electrics, oil hoses and so forth from the engine. The lack of exhaust header studs makes things a bit easier. To remove the engine, we use a combination of cheap motorcycle jack, 2X4 remainders and a 275 lb. man known in the Chicago-land area as "Big Bob". It works, and we're in business.
For all the things I love and hate about the condition I got my bike in, I do love that the PO had hex bolts substituted for the crappy philips cam bolts. The cam cover comes off, and in quick succession, the rockers, camshaft all such stuff follow. Everything looks fine, on to the cylinder head. Here's where it gets interesting. I've alternated between rich and lean dozens of times as I've learned about tuning carbs. To correct any mistakes I've made, I've usually resorted to "Italian tuneups" to make things right. I also overheated the bike once. In short, I've made so many half-assed and ill-informed decisions about "fixing" the bike, that its now time to see what effect all this has actually had on my trusty steed.
As it turns out, all my incompetence has had a negligible effect on the bike. There's black #$%*ty buildup in the valve chambers, but a surprising lack of real nasty calcified stuff. The head gasket comes off easy, explaining why it was turnstiling streams of oil before. I discover wads of bunched up paper towels between the fins. I apparently put them there after discovering oil all over my left leg, during my last road trip. Oklahoma, maybe?
Now for the cylinder, proper. Some slight rocking, and off it comes. As much as I hate the PO, the cylinders still have a nice cross-hatch on the bores, and the bores all measure out to 64.80 mm and above. They're barely out-of-round and each cylinder is within .06 mm of 90ยบ readings, so clearly some major work was done by the PO. Its just odd, the piston and bore sizes - I'm guessing they bored out the sleeves to 64.5 mm, and the 13K miles since then have done the rest?
The pistons look gorgeous. I don't know the make, maybe one of you guys can help identify? At any rate, there's been no oil burning or anything like that, so I'm loath to take #$%* apart and measure stuff. If its not broke, etc. Right?
Of course, I bought the new gasket set made by Athena, who truly are #1 in their field as long as you use your middle finger to denote it. Here is their impression of a head gasket in all its oval grandeur.
A bigger problem might be my bored out sleeves. The gasket measures 65 mm-ish. Not sure if its going to fit, oval nature notwithstanding. Any opinions?
And, as promised, here's the grand fvuckup: I sort of destroyed the oil pressure switch, trying to discover whether it needed a new gasket, since it seems to leak oil at an alarming rate. But, in my defense, NO ONE EVER WRITES ABOUT THE OIL PRESSURE SWITCH. It might as well not exist. Its the Area 51 of the CB 750. Hondaman's book doesn't have anything on it, neither does the Clymer. How else am I supposed to find out about its construction except by rooting around and breaking #$%*? I thought so.
Anyway, part of it broke off and ended up in the crank case. I can't fish it out right now, so I'm going to bed and I am going to hit this whole mess in AM, my man. Tomorrow, I shall hit this bike like MacArthur hit the Philippines. Good night.
EDIT: I deleted the pics that didn't work in the first place. Pics referred to in post can be seen below. Sorry for any confusion.
