1962 Superhawk Restoration: Here I goAnother possibility is an exhaust leak at the gasket between the cylinder head and down pipe. This can easily sound like a mechanical noise, as the engine will telegraph sounds easily. So, the first quick and easy thing would be to check the tightness of your flanges. The sealing flange on the down pipe needs to be flat and parallel with the gasket surface in the exhaust port. Many aftermarket pipes do not have the proper final bend at the top for correct sealing, and the gasket will not crush enough to accomplish full contact. Comparing one of these side by side with a stock pipe will be noticeable. If you've had the stock pipes rechromed (or even if they are "new"), check that the flange has a flat surface, usually by doing a touch-up on a belt sander. This is usually helpful, as a slightly bent flange (or one with surface irregularities) may not seal. Assuming that you're using the "rolled up" copper gaskets (as opposed to the true vintage asbestos "fuzzy" ones), after careful removal, it should be visible if they haven't sealed completely. There are some folks that have doubled-up on the gaskets to compensate for poor alignment conditions, but that is not a proper fix. Good luck, and Happy New Year, Chase
NoiseScott, I have to agree with Davo, It took me about three go's at my valve adjustments to get them quiet. The trick is to adjust, roll the engine over(at LEAST once, even twice) and check again. Other than that I would suspect the advance unit or the cam chain tensioner. D
All the valves are adjusted perfectly. Exhaust is on tight with no leaks. Timing is correct. Noise still persists.
I made sure to re-adjust my cam chain tension at TDC too. I'm wondering if that is the issue. I've heard there should be some spongy "play" if you push on the tensioners rod. Mine basically doesn't even move whatsoever. Even when I push against it with the end of a socket wrench. Maybe moves a mm at most. Does this sound abnormal? Here's a better video of the sound. I feel like its more predominately from the right side. Current restoration: 1962 CB77
http://www.flickr.com/photos/1962_cb77_restore/
Scott, I have no proper audio and no headset for my iPhone this week, so I can't listen. But yes, you should be able to push the tensioner inward (with a high degree of force), against the spring pressure once the bolt is let go. Try letting the tensioner bolt off a turn with the motor at idle; you should see the plunger moving in & out as the camchain runs the ambiguities of its travel. If not then I'd say the tensioner could be seized.
Happy New Year, mate(s)! Hey guys, cam chain tensioner is okay. Double checked tappet clearances on both sides over the past two days while the engine was cool. Everything is good there.
The sound is emanating from right side, more toward the exhaust then the intake. I spoke with LM, he mentioned that sometimes a loose cam sprocket could make similar noises, but if that were the cause it would only be when free of load, usually when de-accelerating. So that one's scratched. I wish it was something more obvious. I'm really just curious as to what else could cause a noise like that.
Current restoration: 1962 CB77
http://www.flickr.com/photos/1962_cb77_restore/
|