Honda Headscratching

If it's like the CB750's , that cam runs in bare aluminum in the head . Not sure how they recondition them .

I rebuilt a 125 some years ago and the cam was loose in the head. Bored it out and bronze bushed both sides. Lasted as long as I had the bike.

Cheers,

Bruce (bruceinbangkokatgmaildotcom)

Did you make bronze split bearings, or just round bushing? How did you you keep them from spinning in the journals? Drill and put in a pin in the bore and a matching hole in the bushing?

This does sound like something possible for me to do with materials on hand.

What would the best bronze type to use this application? Aluminum bronze? Silicon bronze?

Thanks

Gunner

"Upon Roosevelt's death in 1945, H. L. Mencken predicted in his diary that Roosevelt would be remembered as a great president, "maybe even alongside Washington and Lincoln," opining that Roosevelt "had every quality that morons esteem in their heroes.""

Make certain that the gas is fresh. The ethanol blends that are sold today go bad very fast. Everyone that I ride with has started using fuel stabilizer. The mechanic at the local Kawasaki shop claims that he had fuel go bad as quickly as 2-3 weeks. The symptoms you are describing sound exactly like you have bad fuel.

I agree with that bad fuel idea. I had a problem with my Arctic Cat 4 wheeler this summer. After I cleaned the carb and changed the plug and it still ran rough at an idle and wouldn't rev up I dumped the gas for some fresh stuff and it perked right up. The gas in the machine was only 3-4 weeks old. Steve

It runs on bare AL . change the oil, put in something heavy, like STP and drive it till it dies. Its not hard to pull the engine, but why bother. If you try to pull the head you will need to split the timing change. gary

Bronze.

HTH

The fuel was 1 day old. But thanks

As I remember it we bored out the head and pressed in plain bearings with a notch filed in one side. After pressing we drilled a hole down the notched side and pinned it. If you try to drill a hole half in the bronze bush and half in the aluminum head it won't work - the aluminum is softer then the bronze so the drill walks into the aluminum. The notch lets the drill cut mostly the aluminum.

I can't visualize the thing now, it was probably thirty years ago, but I don't remember any problems. Plain bushing in both sides. Cheers,

Bruce (bruceinbangkokatgmaildotcom)

Most carb problems are actually ignition, according to a man who rebuild antique auto carbs. I find that to be true. Points have to operate in a small acceptable range of dwell and timing is critical, but older bikes must be retarded a bit to prevent modern fuel from pinging. Add that to worn advance unit and it won't run so well. You need to find the total advance spec and use an adjustable timing light to set it there, idle timing may then be way off, but that's how it is. The timing gear wobbles? That has to be fixed, and the advance shaft can't be allowed to wobble more than a few thousandths either. Take it apart and find out why.