Bob Wessner has a good post on this topic but most of his pictures have gone. So here is my effort with pictures and random comments:
• I'm only going to make general observations about the replacement faces. I bought them off eBay at a reasonable price. Please draw your own conclusions. They are not Yamiya750 parts.
• Here I am ready to go. I didn't need the hair dryer as it didn't soften the hard brittle plastic holding the
gauge together.
• You will also need fine flat brush to paint the cut outs, a fine tip to do the needles. Humbrol Satin Black
modelers paint and also any brand of Flourescent Red paint but it must have the code number FS28915
(as per Bob Wessner and also the Sandcastonly website). UHU glue is good to set the jewels. Masking tape
is for the needle tips.
• Lucky old me, early series cast housings. Off my bike frame CB750-1012300. It was a shame to butcher
them to get them open.
• This is the ugly result of breaking the cases open. It will be hidden beneath the rubber holders and chrome
backs. The only method as far as I know is to get a screwdriver in behind the plastic and lever it up.
• The clear plastic faces polished up really well using Brasso Metal Polish. Any metal polish would do, I think. It's fine enough so as to not scratch. The one or two deeper scratches weren't fixed using this method.
• Here is a BEFORE picture of the tacho dial. Note that the cut outs aren't painted (left). Note that the thickness of the gauge is larger than the Honda OEM gauge plate (right). Overall, the thickness doesn't show once everything is put together.
• Here's the AFTER picture with the painted the cut outs. Note the square edges to the cut outs in the
reproduction faces as compared to OEM and also to the Yamiya750 ones that have a tiny radius in the
corners.
• This picture is of Yamiya750 reproduction faces. Note the rounded cut outs as per OEM.
• The two pictures above are of the end result.
If you are going to do this job have a look at Bob's thread too. There are a number of things not quite right with these replacement dials but I think it would be very, very churlish to criticize them. Making these parts isn't something you could easily do yourself and we are very lucky in the world of old CB's that there are so many reproduction parts available for us. No one's going to front me up over my "non radius-ed speedo cut outs ©". I've not wound back the odometer as I'm kind of proud that this old bus hasn't been opened up yet and she's still running very well with the original pistons and bearings etc. And it gets it's neck wrung at least once every time I ride her.
