How to stop the carb manifold Allen screws from backing off?

Nice thing about no thread locker, is once the screw is broken loose, you can usually finish with your fingers...at least the outside ones. With thread locker, you'll be re-inserting that wrench about a zillion times.

They will back out fine if you get used to putting the thread locker at the upper end of the fastener based on the application.
The fastener stays put in use but once broken free a turn or two when done as the above they can still be removed from that point easily... fwiw.

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The problem with alloy and washers is the washer can sink into the alloy, even some of the fancy serrated versions.
The curved flat washers from spring steel are quite good though,used convex up so the OD does not dig in as they are compressed... or not...fwiw.

I just fit spring washers and they have never come loose.

ELLIS

The head gets hot enough to degrade the thread lock in my experience. As I mentioned previously, it's actually quite easy to drill the Allen screw heads with a 2mm center drill.

I don't recall where I got them, but the allen head bolts I use on mine are serrated on the bottom side of the head, used with an internal tooth washer the bolts do not come loose. Always use new washers when doing any manifold work as the teeth get crushed down when torquing the bolt.

joe czech said:

this may be a dumb question, but wouldn't this be an ideal situation for blue thread locker? just askin'....

will be mounting the carb manifolds shortly, and was planning on (new) correct internal tooth lock washers, blue thread locker for good measure, and of course, torque to spec.

Click to expand...

of course it can be usefull if it dont get too hot , a good spring washer would probably be ok

was just describing an alternative to drilling, easy if you tig weld

leaning toward these - https://www.mcmaster.com/90895a030. O.D. dimensioned to fit under the cap screw. problem is, just placed an order with MC - hate to pay the (minimum) shipping on one item.