Removing Stuck Flathead Screw with Broken Thread from Romet Engine: Access & Techniques

Hello, yesterday evening I started the engine from the romet. I unscrewed the screws and there was one more left. So I try to unscrew and nothing. I unscrewed this way, unscrewed it until the thread on the screw broke. The screw is on a flathead screwdriver and is difficult to access. Lower gives ss'a. I am asking for help with what to unscrew it. Thanks in advance.



Please correct the attachment according to the link:
https://www.elektroda.pl/rtvforum/topic2053101.html#9767614
The moderation entry applies to everyone writing in the topic!
[_P_]

Specify whether the thread or the slot for the screwdriver is damaged?

Always before unscrewing the screws, it is good to hit the head of the screw with a locksmith's screwdriver or with a hammer.
It helps to unscrew every screw in 99%.
Also, give WD for the night.
If this does not help, you will drill and remove the screw piece by piece so as not to damage the thread.
Broken bolts are a common case when repairing engines.
There are also special springs to recreate the thread.

For now, let's wait for the answer of the author of the topic, because it is not known whether the screw thread is broken or the screw head is damaged.

YureQ wrote:

If this does not help, you will drill and remove the screw piece by piece so as not to damage the thread.

You can also always use a suitable extractor .

The author probably does not know where the broken thread is, how he turns the screw and does not unscrew it, I would bet on the broken thread in the body of the aluminum alloy. In my plant (tool shop) we have something like this for knocking out studs from blind holes, it is a rod with a threaded end and a round weight sliding over it, a simple contraption. I propose to drill a hole in the center of the bolt, thread it, screw the rod into the bolt and pull it out (it should come out without any problems) if the bolt is M6, then the thread in it is M4, if it does not come out, thread the weight on the rod and screw the nut or weld the end of the rod by hitting Knock out the bolt into the nut. There are ways to re-thread the thread, but first remove the screw.

Rebuso wrote:

Temporarily treat advice number 2-5 as p ...... e stupidity There is no point in reaming the thread at the very beginning ...

After all, I did not write about drilling a thread, but about using an extractor. If a colleague does not know what it is, let the colleague find out and do not accuse someone of "p ....... stupid" .

Moderated By _PREDATOR_:

Next time I will reprimand you for such words!

Please refrain from off-topic comments!

I did not pay attention as there was only one screw left, and the thread does not hold, just do not ream anything, two screwdrivers and split the bodies.

Moderated By Błażej:

Of course! It is best to force it between the karters.

I do not trust this type of extractor. They could break the thin walls of the screw being removed or break in the "patient", making the work even more difficult. Many of my friends have similar opinions.

So far, the author of the thread has not responded, so why not wait?

You can do without drilling with an external extractor, put on the screw head, but in the photo the screw is recessed so that it looks like it will not be used, it would have to be adjusted to the groove.

With screwdrivers, you can feel it between the crankshafts, then wooden wedges, the screw will not stick if its thread has a twisted thread.

It's like I wrote. On the head, on the head and it will go

Rebuso wrote:

radio-service wrote:

After all, I did not write about drilling a thread, but about using an extractor

This is the extractor
I wonder how to use it without reaming the screw ...

Rebuso wrote:

Reach the screw head itself with a 6-7mm drill, then you can split the scrap in half, and the rest can be unscrewed with a small frog or some jaws or a vice. Slightly right-left. Nothing by force. Only after it is split in half, you can fill this thread with some means (brake fluid, for example), and even heat the shell to some 120 * C. If you don't know what we're talking about, outsource it to a mechanic.

Temporarily treat advice number 2-5 as p ..... stupid There is no point in reaming the thread at the very beginning ...

You should drill a hole in the screw for the extractor, and not drill the thread as your colleague suggested. Secondly, find out what the extractors are for . Is it not for removing broken screws ?

Quote:

You should drill a hole in the screw for the extractor, and not drill the thread as your colleague suggested. Secondly, find out what the extractors are for . Is it not for removing broken screws ?

Everything is correct, you just have to be very careful. A good steel extractor should therefore be brittle. When it breaks and gets stuck in the hole, no drill will move it, except next to it.
When nothing helps, I mark the center of the bolt exactly, drill first with a small drill and then with a drill so that the thread does not move and the hole is as large as possible. Then a precise, thin punch (e.g. needle from the injector tip)
and the remnants of the screw can be knocked out.
You can, if possible, use a larger screw or insert a spring.
For example such
http://narzedzia-warsztat.istore.pl/pl,category,277635,naprawa,gwintow.html

And I suggest waiting for the author of the topic to write what he broke up, because until we find out, it will not be possible to help him. Probably my colleague has damaged the recess in the screw and he cannot unscrew it because the screwdriver does not catch the screw. However, it is better to wait with the advice until your colleague speaks.

So I mean the recess in the bolt. Thanks to everyone for the advice. Tomorrow I will write if I managed to unscrew.

You really wrote a lot (not necessarily in the subject) and still a lot - because the author did not specify the problem.

The author managed to write at the time I wrote ...

1- an impact wrench will work even in a "weak" cut
2- a finger sander will always make a new Ditch.

Alternatively, when both methods of the colleague56 fail, you can carefully weld something to the head of the bolt (e.g. a hexagonal bolt) and unscrew it.

Motronic wrote:

And how do you weld if the screw head is in a recess and there is a stiffening wall nearby?

The tube (nut) with a pin (internal) weld.

Yes - e.g. a 20 cm long tube (the electrode is 45 cm !!!). This one will stick out a lot.
Please do not elaborate on the problem as it is no longer there.

Probably not. But in the wrench set there should be a cap (black) for the tips.
It is better to use a "hand" impact screwdriver to unscrew it. You put it to the screw and hit the screwdriver with the hammer. The cam in it causes a large instantaneous moment. It works great when dismantling components in the automotive industry.

See e.g. Link