That bolt is not to be installed when you are finished.

When you remove/install the timing belt, you can lift up on that arm, then put a bolt to keep tension off of the belt. Once the belt is in place, you remove that bolt, so the spring can keep proper tension on the belt.

One other pointer, there is a small pivot/post sticking out of the engine block near that tensioner. On the tensioner bracket, there is a small loop that must be installed over that post. This allows the tension pulley to pivot around one point.

Here is a thread with more details about this:

https://www.hondaaccordforum.com/for...warning-22046/

 

Sorry, been outside mowing the yard.....don't have much of a life but I have to keep the neighbors off my butt.

If it is the second pic and the one that has a label of 6 X 1.0 ...that is a temp bolt. It holds the tension off the balance belt so you can cahnge it. Once you have the new belt on it come out. I use one of the bolts from the timing cover to do this.

If it is the "adjusting nut"....different story. You need that one, If you can't get to the dealer for a new one....use some of the nuts you have off the car to find the right size...guess...10mm with 1.25 thread pitch. IAf you have to have it for work, go to a store and find a nut that fits....hope for the best.

EDIT: I see PA posted as I was typing....I'm slow.

 

The green arrows points to the part of the tensioner that needs to be installed on that post in the attache image.

 

I've been busy too, see the other guys have jumped in. THANKS.

That bolt to the left, in Poorman's 2nd picture, is NOT supposed to be there. Think of it as a temporary fixture/tool that can be used. The tensioner nut that tightens down on the center of the pulleys, THAT's the only one to stay in place when you're done.