I've stripped one of my four Keihin 40mm carburetor top cover screws.



There are plenty of allen head screws to replace them. This is probably a dumb question, but all the screws for sale are threaded full length. The Keihin original screws have a sleeve that covers 2/3 of the thread. Obviously, the hole on the carburetor plastic cover is wider than the threaded insert on the metal carb body. Back to the dumb question.....would you buy an OEM screw or replace all four with shiny-chromed-aftermarket-fully threaded-allen heads?

 

They look like phillips, but they are not

A US phillips will "cam" out and strip the head.

 

here is what i do

 

Get the OEM screws if they are available, they are designed to prevent the screw from threading in so far that they crush the plastic cover, if screws are no longer available, ask Buster what size ferrule he used....

One of them is a different length, because it also fastens the throttle cable bracket.

 

Just use a normal SS cap screw and don't reef on it when you install it.

 

the ferrules were common plumbing ones, easy to measure if needed.

 

I replaced all my screws with stainless allen head caps. Top and bottom, much better than stock. As mentioned above, don't crank them with the long end of the allen wrench! The torque you get with the short end is enough. I used flat washers on the top. A lock washer wouldn't be a bad idea either.