Hello all, I'm new to the forum but I've been lurking and reading for about 6 months now, having bought my first bike which is a 91 F2 in June this year.

Now this will be a rather long post so I can explain it properly.

About a month ago I had the classic diesel engine sound which was clearly the CCT. I got an APE replacement, which solved the horrible rattle. However afterwards (I only rode to bike about 150 miles with the horrible rattle, maybe 200), there was still another rattle, coming from the right side of the engine.

I put a video up on youtube which shows the sound, you can watch it here - it's not a very harsh rattle but still pretty bad, most obvious up to about 3 to 4K, then I thnk the noise of my exhaust dulls it out if it persists beyond that (I really don't know if it did).

So a biker buddy of mine said I should probably check the valve clearances. The bike has 52K on the clock and a patchy service history, so it was probable it had never been done.

So I got onto that pretty sharpish with the guides around the web and from advice on here. In the end, I had 2 exhaust valves that were not in tolerance, one was 0.01 out and one was 0.03 out. I also had one intake valve that was 0.04 out. So out of 16, it was looking pretty good. The valves that were out, were on the opposite (right) side of the engine though - so I concluded it probably wasn't the issue.

So now I started putting the bike back together to see what she sounded like. I noted when I took her apart, when at piston one TDC, the IN and EX marks were not totally parallel with the head, we're talking a very minor amount, but I didn't think much of it as I thought it could have just been the angle I was looking at it, and I've always felt it's a fairly general way of measuring timing.

I got her back together, first problem though. When laying the intake camshaft in, with the crank lined up with the T notch, it won't sit squarely on top of the valve buckets, it seems piston 2's valves are stopping it from sitting flat. The exhaust cam fits in perfectly though with the Piston 1 cam pointing the right way as expected. So I assumed that there would have been some spring pressure from some valves pushing up, stopping the intake camshaft sitting properly, so I got it in as best I could and put the bearing cap on, and it seemed to go down straight and the piston 1 cams on each shaft were pointing away from each other. Problem 2. When refitting the cam gears, they definetly did not line up. Now I did this quite late at night and I forgot whether I rechecked if the crank notch was correct, and I have a feeling I might have knocked the torque wrench while it was still hanging. Never the less, I managed to get it back on, and didn't think much of the gears being ever so slightly out. Tried to start, and of course nothing, lots of backfiring so I gave up very quickly, and assumed the timing was out, which when I relooked, it certainly was and much more obviously so.

So attempt 2, I rechecked everthing, piston 1 at TDC at all times, same problem with the intake camshaft not sitting properly. I put the bearing caps on, and now I can get the exhaust cam gear on OK and it's pretty much lined up, but the intake gear, will not line up while the chain is on and the hole on the camshaft for the intake gear bolt seems a little behind in the timing, it's like 2 mm out, stopping the bolt getting purchase, so something is very clearly wrong.

I had 2 conclusions, firstly, and most unlikely, the intake cam is warped in some way. Secondly, but still seems a little unlikey, the cam chain is stretched by a few mm as a result of the dead CCT.

So I request some advice from the vast resource of knowledge, could my cam chain have stretched/damaged that quickly from the CCT? Is there anything else I'm missing? And finally, is the way that the intake camshaft is going in correct? That's what I'm most worried about and my Haynes manual doesn't seem to refer to how it would be seated?

I'm really stressed out about the bike now and very nearly giving up on it to buy a VFR800 VTEC instead....!

Any advice would be really really appreciated, thanks in advance, and I look forward to hopefully helping out some other people with their bikes in the future.