[Head Tomcat]

Guys,

I was installing new air filters in my 2004 749S yesterday and was putting in the last of three screws on the right side holding the air intake runner when one of them suddenly broke off. These screws are "waisted" and thread into a brass insert which is permanently captured by the plastic airbox top cover. Since they are waisted, I am assuming they were designed to do exactly this...break off before the brass insert can be messed up and require a complete cover replacement.

Is there a good way to remove this broken threaded section from the brass insert without taking off the entire airbox cover? I do not want to do that is it would be a hassle to undo the three cables going through the front of the cover...just to remove one broken screw piece.

Thanks!

Head Tomcat in a bind

 

[ProphetPVD]

Hmmmm... without a pic it's difficult to say for sure which method would be best.

It sounds however, like an acceptable solution might be the use of a left handed drill bit. You'll need to carefully drill a pilot hole as close to the center of the broken screw as possible... use a light touch here, with as slow a "spindle speed" as possible. Once that is done, use a left handed drill bit, something made for metal with flute edges as sharp as possible, 1 size larger than the pilot hole you just drilled, and again, with as slow a spindle speed as possible, back the screw out.

You'll need to apply some penetrating oil beforehand, and hopefully, it was not a situation of crossed threads leading to the failure of the fastener. Otherwise, I think you may be looking at having to remove the threaded insert entirely and go with a larger sized insert with a helicoil fitted to allow you to use the same fastener.

 

[2004 999s]

you can just position the lid in the best possible location to extract the screw remains w/out pulling the cables.just slide them within their grommet.be advised the front center screw is in one tough location to reach.maybe easier to remove the key tumbler to reach it.

 

[Head Tomcat]

Wow...that is the answer as I carefully looked at your photo and then weaseled my airbox cover off to the left....will now be getting the screw remnants out!!! I used some rubber lube/cleaner to soften the rubber grommet holding the three cables and then pushed it out of the airbox cover to give me some slack. By carefully moving the cover to the left and rotating at the same time it snapped right out and is now giving me the access I need.

This saved my bacon for sure!

Head Tomcat

 

[Head Tomcat]

GOT IT!

Flipping the airbox cover to the left side gave me plenty of room to very carefully center drill the 5mm screw hole with a 5/64 cobalt drill bit and obtain a clean hole through the center of the broken screw tip. A proper-sized extractor was then worked in with a hand tap handle and the broken screw came out absolutely clean. I then chased the brass insert with a 5mmx0.8 tap to see if there was any damage..and there was none!

I really dodged a bullet on this one and you guys really bailed me out!

Now...with the airbox cover exposing the entire fuel delivery, injection and throttle linkage assembly...I want to go to the next step and learn how to re-set the TPS, etc.

Lonelec OBD cables are already on order and I have been doing a lot of research on IAWdiag software to allow basic servicing of the electronics. While that is a whole other thread...since I have the airbox fully exposed for service, should I go ahead at this time and remove any of the yellow paint used on the throttle stop screws, etc.?

Thanks!

Head Tomcat finally home free

PS: Years ago I had read the front airbox screw was a real tough nut to crack, so I removed it at that time when I was doing some service work. This time I did not have to fight it...thank the Lord.