Seized Motor - CB77
Seized Motor - CB77[forwarded from honda305.com email]<br /><br />Can you help.<br /><br />I have a CB72 in original used condition. I bought from a friend several years ago, he was a meticulous man so I dont think he would sell it to me with a seized engine.<br /> <br />It has stood in my garage and it I cannot get the crank/pistons to move using the kick starter. It is unusual for an engine to seize just by standing. Is there some suggestion you can make to free the engine. If not it will have to be sold.<br /> <br /> <br />Mike Walton<br />michael.walton2@ntlworld.com
Re: Seized Motor - CB77
Re: Seized Motor - CB77Mike, I take out the spark plugs and put fuel oil down the holes and let set over night, then take the round plate on left side of<br />crankcase off. You will see a bolt, this holds on the stater and also will turn the crank shaft. You will need a socket with a long handel for leverage,try and move the bolt back and forth, this will take soom<br />effort. It has work for me. If you need help call me, Jim 612-386-3573<br />P.S.CHANGE OIL AFTER YOU GET IT TO CRANK OVER
Seized Motor CB77A suggestion, if I may,( after letting the fuel oil soak in for a while)
sometimes you ca put the transmission in gear (like 2nd or 3rd), and rock the bike back and forth to break it loose. If that doesn't work, I have pulled the clutch lever in (while the trans is still in gear) , pushed the bike backwards, popped (quickly released)the clutch and broken the engine loose. The rings are probably rusted in the cylinders. Good Luck with whatever works. Later on, Bill Re: Seized Motor CB77********************************************************** I have just unseized a solid 1962 CB72 engine. It was foolproof and only puts force on the pistons (not crank) and cylinder head & studs. First, I soaked the piston and cylinder in "plus gas" - diesel fuel oil will do. If you can leave it for a couple of weeks all the better. I already had the cylinder head off. I filled both cylinders with grease above the 10 mm deep puddle of plus gas. I also filled the cylinder head chambers with grease, making sure that all four valves were closed - just turn the cam on a 180 degree motor, or slacken the valve adjusters on a 360 degree motor. Reassemble the head, using an old head gasket. Tighten all the head bolts down. I took off the bottom crank case to allow the crankshaft to drop when the pistons move. The next bit needs a bit of work. Get a couple of old spark plugs. Hacksaw or file off the swaged bit of metal where ceramic and the steel body meet. Remove enough steel to get down to the hexagonal section. File off the lower outer electrode and you should be able to drive the ceramic out. It tends to break up a bit. Cut yourself a short length of steel bar 12 mm diameter x 25 mm long. Fit it inside where the ceramic was and weld the bar to the plug body, make sure there are no gaps in the weld. Clean up the hexagon if required. Drill down the centre of the bar, tap the end to suit a grease nipple, I used M6 metric thread. When you have made 2 of these plugs, fit them to the cylinder head. Use a lever arm type grease gun to pump grease into each cylinder in turn. It takes quite a lot of grease, but you sould be able to push each piston down the bore. My pistons kept travelling down in jumps. I kept swapping from one side to the other, and let the crank lower itself, evenly. I prefer this method for heavily seized engines as all the force is spread evenly over the entire piston, and nothing at all on the crank or gearbox. Other things to try and help - using a hot air gun or propane/butane blowlamp heat the barrels up all over to 100c. It might help to try this prior to using the plus gas or diesel fuel. Please email me if you want a photo of the special adapted plug. [/img]
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