MFI throttle body cylinder head stud for '73 911S.... M8 *22?

[neilk]

Hello,

I am looking to finally swapping the carbs on my 73S with MFI. The current studs for the carbs appear to be too long due to the spacer between the heads and the carbs, so can someone please reconfirm that M8 * 22mm studs are the correct size? That is what I see in the Parts catalog on page 30, part # 900.061.007.01. (looks like it has been superseded to 900.060.106.01).

Lastly, I think I have one slightly loose throttle plate. I may have slightly damaged it when trying to get the plate unstuck from the sides of the throttle bores. Can I repair that, or does that need to be sent out to a specialist. It looks like there maybe a couple of degree play when I open it.

Thanks,
Neil

[RSTarga]

If the throttle plate was jammed into the bore it should be rebuilt. In dallas area the closest shop that knows these systems is Ed Mayo at Mayo Performance in Fort Worth. In San Antonio, Jones Autowerkes can do them too. Or send them off to Eurometrix or Mark Jung.
If your throttle plates have play, you'll never be able to set the MFI correctly.

[30westrob]

I had exactly the same issue with the reinstall of the MFI on my 73 911S targa. The 22mm spec in the parts manual is the stud exposure, and not the length of the stud. I used a die grinder and cut the long studs down to 22mm of exposure. I took reasonable precautions to prevent cutting residue from getting into the engine. All worked well. Rob

[RSTarga]

If one of the screws from the throttle plate drops in the intake port you will be facing a much higher bill than having them rebuilt by an expert.

[YTNUKLR]

yes, that's the correct replacement stud.

the snap-on CG-500 stud-remover/collet is a must-have in your tool box (of course, for this you will need the insert for M8X1.25 threads). You can try to double-nut the stud to remove/install it if you don't have/get the stud remover tool. if you chop the stud with a cutoff tool, you have to clean up the edges and/or rethread the stud with a die. YMMV, but I'd just replace the studs with the correct new studs (all of $24 retail cost).

sounds like you need to have the throttle body repaired professionally.