Repair Suzuki GSXR 750 98

I started to take it apart a little bit. 

In order not to do a lot of extra work, unscrewed the pallet, and found a couple of bolts squeezed off specifically, many are not tightened at all. 

In the pallet besides dirt, metal filings. 

under the cover on the right side, everything is clean, but the metal is not a healthy color. Not everything is clear, so I decided to open the cylinder head. On the first cylinder, on the throttle body there are traces of gasoline, oil and dirt. Normally, it's dusty and dry. 

The valve cover has oil on it too, but that has nothing to do with it. Just for the record. Since I'm taking everything apart one by one. The goal is to get to the plugs. Here it is, from the first cylinder. 

The photo shows the corroded electrodes. The verdict is simple. Valve(s) failure in the first cylinder. And pieces of something:

Shaken with difficulty out of the exhaust pipe, turned out to be nothing more than a

by the valve seat. 

Since my friend (the owner of the motorcycle) decided to simply replace the motor, there is no point in disassembling further. The picture will be familiar to us.

So, to summarize:

1. Unknown and therefore not quality oil.

2. Tired valve springs.

3. poor quality previous assembly - repair.