CB750K8 Oil gallery cap and lower crankcase plugs

[martin_uk]

These always seem to be chewed up as have quite a shallow hex head.

Thread is 20 x 1.5

Has anyone tried alternatives?

I see there are some sump drain plugs with same thread, allen key fitting seems better, although not original.

Interested in your thoughts 

[martin_uk]

I decided to go ahead and order a couple of these as thread is same size as Honda cap and had advantage of magnet to trap metal particles and fairly cheap 

http://www.ebay.co.uk/itm/281523874391?_trksid=p2059210.m2749.l2649&var=580549659651&ssPageName=STRK%3AMEBIDX%3AIT

Arrived today and although slightly different to image (head is concave)

2015_0303eng0022 by nitram2010, on Flickr

Not too keen on reduced section at base of threads as means sealing washer can misalign.

Have ordered up some Dowty Viton washers which I think would work better.

You could not use O ring as does not have retainer groove like original.

2015_0303eng0015 by nitram2010, on Flickr

Magnet is quite strong

2015_0303eng0021 by nitram2010, on Flickr

Loosely fitted without washer

2015_0303eng0016 by nitram2010, on Flickr

The original has a 14mm head, so presumably Honda did not want them overtightened, so care would be needed.

Not sure if I will fit, but If I do will probably start with top gallery so easier to keep an eye on.