77 GS750 tach bracket on engine

[tjhenry]

ok, so on the front where the tach goes into the engine is my problem

i bought a new tach cable because the part that went into the instument panel was held on by a zip tie

when installing the new cable, i noticed where it screws into the engine, there is a hole on the right hand side, it looks like there is a bracket where the tach screws into, but it's broke, and there is sure enough a broken bolt in the hole

1. where in the world do i get this outer facing to replace the broken one

2. what's behind that screw hole? i'm going to drill it and then back it out, but is there any danger of me hitting anything behind it if i go to far?

[LarryA_Texas]

If it's like the later models you can see everything you need to see by lifting the valve cover. The bolt that is broken goes into the head and the gearing that drives the tach cable is clearly visable when you look under the valve cover. You'll see from there what you're drilling into.

Now's a good time to check the valves and replace the valve cover gasket.

[tjhenry]

does anyone have a extra piece laying around, so when i take this one off i can replace it instead of using a broken one?

[bwringer]

You've seen this, right?

http://bwringer.com/gs/tachcableseals.html

The fitting on your engine might be a one-piece type 'o deal instead of the separate tab and fitting like mine, but the idea is the same.

You can drill and re-tap the hole for the retaining tab fairly easily. Get a 5mm X .80mm tap and buy a new drill bit in the size listed on the package. This screw is only 12mm long, so you don't need to go very deep at all.

If you've never used a drill and tap before, Google around -- there's a technique to it.

[tjhenry]

i had not seen that, but i looked it over pretty good, that piece isn't broken, it just locks it in place, that makes sense

i went to drill a hole in the screw and it backed in pretty good, so i stopped, my next question is what's behind that screw? if there's something i should be worried about backing that screw into? i don't want to take the valve cover off if this is just a hole and it will stop once it hits the back with no damage to the engine, as we've got about a month left of riding here in wisconsin and i plan on taking it all apart this winter to clean it and replace gaskets

[bwringer]

It's just a small blind hole for a short retaining screw. The screw is only 12mm long.

Perhaps you can rig up some other way to retain the tach fitting in the meantime. There's no outward pressure on it, so perhaps safety wire?

[tjhenry]

i have some Rockset, it's a high temprature adhesive, reckon that would hold it for a month?

i'm tempted to try that, and then rebore this winter