wingsfan98
New member
So here is the background to this post. I have a 1984 gl1200a. When I first picked it up, it needed a starter switch (the key switch on handle bars) and a timing belt (left side as if sitting on bike facing forward). Replaced both and everything started as it should. Had fairings and body pieces off to repaint. finished painting and put all together. Was idling in drive and ramping up and down. at 4600 rpm's, it shattered a valve in the number 2 cylinder (front left). Destroyed cylinder head and piston. Took engine out of frame and replaced piston, cylinder head (replacement came with valves, springs and all the internals) and gaskets. Put everything back into frame, set the timing and hooked everything up.
First thing to happen was the starter relay (switch between battery and starter) stopped working and had to bypass with a dead switch. Tried to start engine and all it does is Backfire, alternating between exhaust and carbs as to where it is back firing. Sounds like it is the left side only doing it. But will not start. Took apart front timing covers and reset timing from scratch, reassembled and still same problem.
So, what is the most like cause of this? I keep reading several different things on this forum, but where do I start to trouble shoot? What is most likely to least likely? I am dumbfounded as I can see nothing obvious that is causing this. Like I said, it ran fine before the valve went.
First thing to happen was the starter relay (switch between battery and starter) stopped working and had to bypass with a dead switch. Tried to start engine and all it does is Backfire, alternating between exhaust and carbs as to where it is back firing. Sounds like it is the left side only doing it. But will not start. Took apart front timing covers and reset timing from scratch, reassembled and still same problem.
So, what is the most like cause of this? I keep reading several different things on this forum, but where do I start to trouble shoot? What is most likely to least likely? I am dumbfounded as I can see nothing obvious that is causing this. Like I said, it ran fine before the valve went.