WD40

A bit of cam chain noise on those bikes is normal because they have an automatic cam chain adjuster and sometimes it takes a while for the tensioner to advance to the next notch so you get a bit of cam chain ticking that rises and falls with engine rpm. Here's a video of Fazer cam chain noise And here's a video after a new cam chain was put in His noise sounds similar to me be a lot more harsh like the cam chain has gone totally slack instead of just the normal amount but I have no idea why his cam chain would go slack after the work he's done.

Sounds like a slack cam chain to me but I have no idea why the cam chain would have gone slack

10mm will be fine. If you think about it it's not possible to drill into the cylinder because the exhaust studs are in the head and the head is above the cylinders so you're drilling above the cylinders. You know what I mean? If you look at the picture. If you went to deep on the the outside exhaust stud you'd go through the passage where the head studs are and hit the head studs. If you went too deep on any of the other ones you'd go into the water jacket which is the space where coolant circulates to cool the head.

If the only exhaust stud you drilled too deep was the outside one I don't think it is possible to drill into the cylinder from there. If you went too deep there you'd be drilling into a head stud not the cylinder. See the rounded section in the engine casting in your picture? That rounded section is for the head stud. If you went too deep into that exhaust stud you'd hit the head stud. You could try some talc powder around the header or baking flower to look for an exhaust leak. The long screwdriver trick is a good idea too.

The last time I went camping on the bike I spent the whole day riding and I ended up pitching the tent on a beach in total darkness. Seemed like a good spot. The next morning I woke up and I was lying in the sleeping bag. I could hear things dropping off the tent roof! I was thinking what is that noise so I look around and the tent is covered in earwigs! Hundreds of the fookers. I pitched the tent on a earwig hotel

@Tiggie Nightmare. Sounds like you have it under control now

I agree the nut has shear off. I was talking more about the outside part not the nut. Seems like the outside has been broken off too. Maybe with a grips or with a chisel. Few pics there https://www.ebay.co.uk/itm/Yamaha-YZF-R-125-2008-Crank-Cases/291749370716?hash=item43ed9e1b5c:g:AC8AAOSw4hdXIGkZ

He probably backed up the toilet so much the only solution was to demolish the whole bathroom.

I'd say he snapped the bolt and then tried a grips on the outside and chewed up outside

What happened or should I not ask?

I think the sensible thing to do here is admit defeat and hand it over to a mechanic before it gets any worse. The drain bolt screws into the engine case not into a sump and the case splits vertically. If you damage the case or the threads in the case you would have to take the whole engine apart to replace the case or put a used engine in.

Could be a bad connection at the battery causing voltage drop when the starter tries to turn. You have a lot of connections on the battery terminal.

I always stop. Haven't been robbed or shanked yet Usually they just wave you on. One time I broke down on a motorway. I had the tank lifted and was looking for the problem when a guy in a van stopped. He was coming back from a track day so he had a full set of tools and a dummy fuel tank. He hooked up the fuel tank and the bike started and I was back on my way

Years ago a friend put the gear linkage on the wrong way on his cbr250rr and the same thing happened. It changed to up one for first gear and down for all the rest

If you leave it parked outside for long periods make sure you use a thick chain lube or it will wash off and ruin your new chain.

On the plus side the inside of your engine looks nice and clean. No staining or sludge. It must have got regular oil changes throughout it's life. If I'm trying to get an exhaust on I sit on the ground and put my foot under the end where it joins to the link pipe and then wiggle the headers in while moving my foot.

Haha I agree

Yes. Hello everyone

I think you've drilled into a passage that one of the head studs goes through. Have a look at the pictures https://www.ebay.co.uk/itm/Head-Cylinder-Yamaha-FZS-FZ6-600-Fazer-J501E/174640649186?hash=item28a964d3e2:g:tpEAAOSw8OteLwIY https://www.ebay.co.uk/itm/Cylinder-Head-Yamaha-Fazer-600-/133426632071?nma=true&si=c9VRyzGVUBALtJJ3QXpqvST0%2F1k%3D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557 The fazer has long studs that thread into the crankcase. https://www.ebay.co.uk/itm/Yamaha-FZS600-Fazer-1998-2000-Engine-Crankcases-Crank-Cases-J501E-014202/333857330872?hash=item4dbb7296b8:g:MEUAAOSw~DNgAE9q Nuts hold the head to the cylinders. The nuts that hold the head are recessed into the camshaft journals. I think the oil you're seeing is what has collected around those nuts. If you can seal the exhaust stud threads and stop the oil coming past the threads I think you will be fine. Your best chance of salvaging the head is probably to take the head off and bring it to an engineering workshop and they will try with getting them out with a welder or just drill them out.