Greetings,
I'm still working on my project bike (72 Jackpiner Black Engine) and have a couple of questions on the head and jug. First off, I pulled the head and jug from the box the rest of the engine came in (this puppy is a true basket case) anyway I was examining the head and noticed a real lot of pitting in area that would be inside the id of the head gasket, its not in the center domed portion where the spark plug comes through but outside of that area. I was wondering if this is normal or a problem? Should I just smooth it out with a dremmel or leave it alone? Also in the same area there is a small blind hole, about 3/32" in diameter and 1/8" deep. Is this something that is supposed to be there?
My second question concerns bent fins on the head and jug. I have a couple and was wondering what would be a good way to straighten these out without breaking them. I was thinking of just applying a little heat with a torch and then flattening them out with a pair of duck billed vise-grips.
Any advice would be appreciated!
Thanks,
KD
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Kevin J. Donovan
Foster, Rhode Island
Before bending aluminum you must anneal it so it will not snap off. You can anneal by bringing the aluminum up to 700degrees F, or by coating the aluminum with acetylene soot and heating it enough to burn off the soot. The aluminum will retemper itself over the next couple of days. Good luck. Rick
Kevin: In regards to the pitting in the squish area it is somewhat common on bikes that did not get taken apart regularly but only after they quit running. What you are looking at is what happens when the piston ring breaks and or piston and the tiny pieces get hammered into the head. Usually you can smooth out the high spots so there is no sharp or jagged corners to cause detonation and reuse the head. Have no idea as to the hole you are spaeaking of though.
If it really bothers you, you can have the head welded and remachined on a mill at a machine shop. Measure the volume of the head (in cc's with liquid) and make sure it is the same as possible-I have sanded them back down with emery the get close.
James
Yamazuki-Kawahonda all sounds the same to me.. Real bikes were made in Europe
Kevin if you need any parts for the black 175 i have a lot of them and i dont own a black engine 175 so i dont need the parts.All mine are silver except for a 73 250.Herm
Herm
After a closer look at my head and jug I figured out what caused the pitting and blind hole in the head. Near as I can tell when the connecting rod broke (it broke where it attaches to the crank) one of the rollers inside the cage bearing headed north, it left a 1/16" deep score in the sleeve and then was pushed into the head making the blind hole and I am assuming the rest of the pits. I have a tig machine and can weld repair the hole but I am not sure of the grade of aluminum. I have both ER-4043 and ER-5356 filler wire. Anyone here ever weld repaired one of these heads? OR Does anyone know what the exact grade of aluminum the head is made of?
Thanks!
Kevin J. Donovan
Foster, Rhode Island
Herman,
You have mail, get back to me when you get a chance.
Thanks,
KD
Kevin J. Donovan
Foster, Rhode Island