Unknown part in cylinder - 82' XJ650 Maxim

Hey guys, me again. After the success of getting new keys for my 82' Xj650 Maxim, I decided to clean the tops of the cylinders to get ready for placing the new head seal and reattaching the head. When doing so, I noticed these black tubes sheathing the cylinder bolts. They appeared very corroded and crumbled in my hands, so I checked some parts diagrams to see if it was something I would need to replace but had no luck identifying what the part was.

Anyone have any idea what these are? If so, is there an easy way to replace them, considering some of the crumbled bits of them are down around the middle of the cylinder bolts? Are they completely necessary?

Also wanted to know your recommendations for cleaner to remove the remnants of the previous head gasket. Thing basically dissolved, leaving an uneven splatter of hard black goop all over the top surface of the cylinders. Stuff does not want to come off, even with a wire brush.

 

You can see the front cylinder studs through the cooling fins, so water would get to them. The sheathing was fitted at the factory to cover the studs to prevent or minimize corrosion. I used 9mm or was it 12mm cable tube when rebuilding my engine the stuff that is used for electrical wiring and shrinks when heat is applied to it. I had the cylinders off so it was easier to replace them.

 

the tubes dont go on all the studs

 

Alright, good to know. Any thoughts regarding cleaning the old head gasket remnants off?

 

I used a stout plastic scraper. Try brake clean or Acetone to remove any gasket residue. Metal scrapers can damage the aluminium that's why I don't use them.

 

yep, dont put any of the heat-shrink tubing on the two R.H. side cylinder studs, as they are the oil gallery feed studs

 

Paint remover(or gasket remover) and a plastic scraper will get the old gasket off. use the old clemical stuff not the new environemently frendly kind.

 

I got it all off with the plastic scraper and some brake cleaner. It's all ready for the new head gasket now. Thanks guys.