Item 8 in this picture - tongued washer?

[McCabe-Thiele (Ted)]

As it was missing on my 500 I am fitting the chain guard that bolts inside the left side chain case cover.

Two M6 bolts hold the protector in place, one has a spring washer, the other has a tongued washer part number 90532-323-000. that is  shown as no longer available.

Is it okay to use a spring washer instead or is the tongued washer an essential locking tab?

Do I need to fabricate a lock washer for this location?

.left-crankcase-cover_bigma000082e11_91d1 by Macabe Thiele, on Flickr

[K2-K6]

"Is it okay to use a spring washer instead or is the tongued washer an essential locking tab?"

It looks like the spring washer is on a bolt isolated from the chain run, with the tabbed bolt having extra security being in vicinity of the chain and sprocket rotation  ?

I can't tell fully from the diag, but that would make sense for the type of fixing security they provide.

[McCabe-Thiele (Ted)]

"Is it okay to use a spring washer instead or is the tongued washer an essential locking tab?"

It looks like the spring washer is on a bolt isolated from the chain run, with the tabbed bolt having extra security being in vicinity of the chain and sprocket rotation  ?

I can't tell fully from the diag, but that would make sense for the type of fixing security they provide.

Yes I can see that now you mention it - not sure where the tab locks into as it's not clear from the parts book - possibly it latches into the large round hole.

I will play safe & make a locking tab as I do not want to risk a bolt coming loose & striking the chain.

[K2-K6]

Yes, I'd view as you do Ted, in that the lock tab appears to anchor in that nearby hole to secure.

Some of the others with more experience than I of 500 could likely shed some more focused light on it for you .

[Oddjob]

I'd say you hit the nail on the head Nigel.

[Trigger]

"Is it okay to use a spring washer instead or is the tongued washer an essential locking tab?"

It looks like the spring washer is on a bolt isolated from the chain run, with the tabbed bolt having extra security being in vicinity of the chain and sprocket rotation  ?

I can't tell fully from the diag, but that would make sense for the type of fixing security they provide.

Yes I can see that now you mention it - not sure where the tab locks into as it's not clear from the parts book - possibly it latches into the large round hole.

I will play safe & make a locking tab as I do not want to risk a bolt coming loose & striking the chain.

If you do not want it to come loose, just put thread lock on the bolt 

[K2-K6]

I'd say you hit the nail on the head Nigel.

Cheers Ken, 500 experts have better knowledge about these detail

[Oddjob]

Not so sure it’s knowledge Nigel, more common sense in a lot of cases and an understanding of how the Honda engineers seemed to think.