Removing throttle plate screws?

I'm not familiar with your specific problem but would an "impact driver" be of assistance?

http://en.wikipedia.org/wiki/Impact_driver

Not sure how delicate the part you're working on is though. It might not be able to take the shock of impact?

 

most of the time the throttle plate itself is the female screw, and the screw is split on the other side.
Open the throttle completly and see if the screw is split ! Press the 2 half back together without damaging it. Try now to turn the screw counterclockwise..

Good luck,Guido

 

They've also used the method of "staking" the end of the screw (which is simply driving the exposed end of the screw with a cold chissel).

The best way to remove these is to actually grind that portion of the screw off, flush to the shaft, then unscrew them out. If you simply unscrew them out without grinding, that deformed portion of the screw can damage the fragile threads on the throttle shaft. Obviously, since grinding causes metal dust in that area, you'll want to thoroughly wash these out before putting it all back together.

 

I don't see why they wouldn't come out after grinding.

 

Okay, good luck!

 

There's a possibility they've been Loctited in, as well, so a bit of heat from a micro type pencil torch may be needed to break the thread locker. Might be worth a try before grinding.

 

It is entirely possible that something like green Loctite has been applied to those screws. If that's the case heat will be necessary. As a last resort you could drill out the screws and replace the throttle shaft if damaged.

Good Luck

 

be careful not the bend those shafts, i did on accident in the process of replace my bearings and didtn realize it until after i put them back together and tried to sync the carbs.

 

The parts are very delicate and an impact driver, with no back up on the split side would almost surele bend the shaft, making it necessary to replace the shaft.

Grinding off the staked or split end is the way to go.

Order up some replacement screws from someone like Pierce.

Also, it is a good idea to mark which throat the plate came from and which side is up. You can make reassembly go a bit smoother by carefully scribing the shaft location on the butterfly.

HTH,
chris

 

When reassembling the carbs, i was quite concerned about securing the butterfly screws AND not bending the shafts.

What worked for me was to get the butterflys adjusted as close to "light tight" as i coud before staking.

Then I turned the carb over, placing the phillips screw on a long #2 driver bit held in a shop vise. You need to rotate the carb slightly,so that the driver bit is firmly seated on the butterfly screw, then, with a small hammer and a sharp metal chisel, gently tap the chisel, on the supported screw, to stake it.

Having a third or fourth hand to steady the carb is a good idea.

Good luck,
chris

 

Another way a ferrari wrench showed me was to crush them with channel locks putting screw in compression deforming just enough of the end threads to stop the screw from backing out. In this way you have no chance to messing with the plate or the shaft, plus it's faster.

 

Next time....


thanks,
chris

 

I wouldn't have thought of that... Thanks for that tip!