It would be #7 in this picture. When I opened the bike up to do valve clearances there were only 3 bolts holding this on...the fourth was broken off in the threads. So I took it off and did the clearances. Now I am haveing a hard time getting it back on,and even if I do it will only be with 3 bolts. My question is...what does this actually do and is it absolutely neccesary to have back on. Thanks

 

The cam chain guide - if your chain has any slack the guide prevents the chain from jumping off the sprockets and destroying the engine, so yes, I'd say it was important....

 

I agree

 

+++++++++++++++++++++++++++++++1

 

Point taken....I will make sure I get it back in one way or another...thanks Guys

 

Took about 3 hours but I finally got it on last night....It was wierd, I had taken it of when I was doing the valves because I wanted to see the chain slack. It was off for probably 2 or 3 weeks and the threads completly filled up with a semi solid gunk.... I have no idea what it was....but like I said it took me 3 hours to dig it out and clean the threads all up last night...but got it back in.

 

It may have been Loctite or a similar product.......?
Good to hear it's back in there...!