Servicing webers - problem with stubborn screw.

[johnfm]

So, this screw doesn't want to move.

How to I convince it to rotate without further damaging the slot or the rest of the carb??

[stevieturbo]

Tried soaking it and soaking it with a suitable penetrating fluid ? For hours, not minutes.

Most suggest Plusgas is best, although WD40 usually works well.

Other option is try heating it.

Also a good whack with a hammer/punch can often help to loosen the threads.

[Jazoli]

If that all fails you can cut another slot with a dremel going in the other direction to give the screwdriver a fresh edge to bite against, if that fails use a large drill bit and drill the head off the screw, which will allow removal of the plate and you should be able to get some grips on the remains of the screw and undo.

[Steve_D]

Jazoli said:

If that all fails you can cut another slot with a dremel going in the other direction to give the screwdriver a fresh edge to bite against, if that fails use a large drill bit and drill the head off the screw, which will allow removal of the plate and you should be able to get some grips on the remains of the screw and undo.

I suspect that plate is quite thin so if you drill the head away there will be nothing below to grip.

Try an impact screwdriver.

Steve

[pingu393]

stevieturbo said:

Tried soaking it and soaking it with a suitable penetrating fluid ? For hours, not minutes.

Most suggest Plusgas is best, although WD40 usually works well.

Other option is try heating it.

Also a good whack with a hammer/punch can often help to loosen the threads.

Similar to the "good whack", but different...

With the carb in a vice (workmate is better), use a good fitting screwdriver with a long shaft and apply as much torque as you can without slipping and lightly tap the screwdriver handle with a lump hammer (yes, bigger is better). I've found that the "trick" is light taps with a heavy hammer. Don't lift the hammer more than 1/2" and let the hammer fall naturally onto the top of the screwdriver. Tap rate is about two per second. It works in the same way as an impact hammer, but is better for small screws as it is more gentle. It usually starts to move within a minute (by which time your forearm will look like Popeye's .

The longer the shaft in the screwdriver the better as the shaft should be twisting (you won't see this, but may be able to feel it).

[johnfm]

Cheers all

Will apply penetrating fluid overnight.

Will also try impact driver.

Other than that - seems fairly straightforward to pull apart, clean and put back together.

Float clearance seems way out. Will put a measure on it, but both float dimensions ( 7.5mm gap and the total gap when fully open) seem a bit out.

The state of some o-rings suggest this hasn't been serviced for some time.

[ch427]

can help to use a small chisel too to shock it loose, place the chisel in the damaged portion of the screw and tap it anticlockwise with the hammer as if undoing it.

[johnfm]

Decided not to change the spindle bearings - as the throttle spindle isn't exhibiting any sticking etc.