Hey all,
I have recently developed a crack in the engine block on the right side of the cam chain galley of my '80 CB750F - pix below. This has come as a shocker as there hasn't been any excessive cam chain noise - a little intermittent buzz here and there at idle - the buzz becomes a feature at 2000-2500rpm before nearly disappearing completely at higher revs.
I've put on 700km since my last oils change and the used oil was normal no plastic sludge or metal filings - thinking the cam roller or forward guid had let go there would have been evidence. I'm told that if the guide had in fact gone the buzz would sound more like a chainsaw and the noise I'm hearing doesn't sound that alarming. Some buzzing cam chain noise is normal but I'm not experienced enough to know where to draw the line on normal.
I took the bike for an inspection for a second opinion and the thought was my suspicion, metal fatigue. I'd like to think that was the answer - patch it up with JB Weld and keep riding?
A similar crack is appearing on the left side of the cam chain galley leading me to think the chain has enough slack to rattle side to side and would eventually just saw right through.
I adjusted the cam chain tension on the front chain on the rear of the engine and that seemed to give a slight reduction to the noise but the buzzing still persists at 2000-2500rpm.
Anyone ever experience anything like this?
I have access to a brand new engine which would be on par with the time and labour it could take to tear the current engine apart replace the block and resolve this.
Locked
