Stuck throttle butterfly bolt. Any ideas?

[overrun]

I am having issues with sticking throttle shafts on my Waverunner's twin carbs.

I have the carbs on the bench and have sorted one side. This still had the OEM phillips head screws holding the throttle blade to the shaft and only required the factory deformed end threads to be cut off and then I was able to extract them, easily.

The other carb is a different story.
The throttle blade is held in with 2mm head allen bolts and I managed to get one 1/3 of the way out with the allen key and then the rest of the way with mole grips, but the second one won't budge and the allen key and a torx key just slip.

With the head being flush, I can't get the long nose mole grips on it and when I clamp them to the rear threads, they just slip.

Aside from drilling it out, which I really do not want to do, or hammering a torx bit etc into the head, again not something I want to do, does anyone have any suggestions?

[RichardMoss]

Have you tried an imperial hex key to see if that might have a tighter fit?

[overrun]

Have you tried an imperial hex key to see if that might have a tighter fit?

 

Good suggestion, mate. I have not.

If I attempt to turn right, the 2mm key is a good fit, but the head is chewed in the left direction.

 

I will see a mates dad and see if he has a suitable key.

 

Cheers.

[Guest James7]

If there is nothing too important near it like seals etc a bit of heat may help. Along with a torx bit hammered in. But if you do that support the shaft well so it does not bend etc.

[overrun]

There are no seals etc there, I did consider heat, but have purposely held back from attempting too much, atm, incase I make a mess.

 

Will consider this option. Thanks, mate.

[twosmoke300]

Try and work back and forward with heat and good penetrating fluid

[Asimo]

Have the threads been crushed behind the spindle to lock the screw? If so drill the head off the screw.

If not there may be Loctite etc on the thread in which case heat will help.

Check your Allen key, these are often rounded at the end: grind a new end on the key so each face is nice and sharp and square. If no grinder, it wont take that long using wet and dry with the 2mm key. There is such a shallow hex hole in countersunk screws, can make quite a difference.

[overrun]

The threads on these allen bolts have not been crushed, as they have been added after the factory.

The other carb still had the crushed factory jobs in and after a tickle with the Dremmel, came out no problem.

 

There is no evidence of any thread lock on the one allen bolt that I have removed, although it felt as though it had.

 

Cheers for all of the suggestions, folks. Will get on this tomorrow, once we return with the clutchless T5 of value.