maktec

My Feedback: (29)

Hello, I am trying to remove the allen screws from the valve cover on 120 4 stroke to check the valves, they are nearly stripped inside and very tight, ANY ideas to remove?
thanks
happy flying
George

rctrax

If they strip I use a drill about the size of the screw itself and drill the head off and then after you have the cover off you can easily screw out the rest of the screws.

voyager_663rd

There are bits called "screw extractors". for just that purpose. comes in various sizes. here's one.

rctrax

If they strip I use a drill about the size of the screw itself and drill the head off and then after you have the cover off you can easily screw out the rest of the screws.This of course means the replacing of the screws with new ones.For replacment hardware check withhttp://www.microfasteners.com//index.cfm They should have the screws you need for a fraction of the cost of tower or OS

Ed Smith

Those extractors are commonly called "Easy outs". Try using one of those on a three or four mm screw.

Ed S

maktec

My Feedback: (29)

HERE iT IS, I heated the screw "boss" with torch, they came right out.
thanks
george

CafeenMan

FYI - normally these bolts strip because the wrong size driver was used such as a kinda close imperial driver in a metric fastener. The other reason is using cheap drivers.

I bought a full set of Wiha drivers (imperial straight hex and ball drivers and metric straight hex and ball drivers) and have had no more problems with stripped heads like I did when I was using Dubro junk. The Wiha's are expensive but really worth it.

I've had them for almost 5 years and all of the drivers look like new. None of them have rounded at all.

keepiru1

Also, when needed, you can use left handed twist drill bits......especially if you have a head to bite into. Working on automobiles over the years I've blessed the four piece set I have. They've taken out, literally, thousands of bolts. Just my .02 worth. And now I have found them recently for cheap at Harbor Freight

rcdude37

use a dremel with a cut off wheel and cut a slot in the head so u can get a flat head in it... or if you want to get technical you can cut a "cross" in it and use a philips.... eather way works, just have a slot on the screw, but you still have the head!

spinin

[>:] you propbly have it fix by now BUT next time take your allin driver with a screw driver handle insert it in to head then take small b.f.h. and give it a rap or 2 then turn it in untill you see it move or here a click then back out normally trust me it will do the trick A&P TEC

narpets

As was mentioned... Use better drivers to prevent this in the future , but here's a trick to remove it if you haven't already. Get some valve grinding compound with diamond dust in it. Not sure of the exact brand as I got some from a mechanic buddy years ago. Now dip the tip of the allen key in the stuff. With a fair amount of downward pressure, turn as normal. Works equally well on stripped Phillips head screws. I have yet to have this fail to get a screw/bolt out; even on Phillips screws that appear to be hopelessly stripped.

Rotorwrench

Narpets is right about the valve grinding compound. You can get a tube at just about any auto parts store. I use Permetex brand because that is the most common brand in the States. The most common cause for stuck or stripped screws are worn out tools and incorrect procedures. Use only good quality tools that do not show any wear and if you have to use higher than normal force to break a screw loose STOP! If the screw might have Loctite on it or it's a steel screw in an aluminum part, use some heat and the aluminum will expand to make the screw come out. Or use a little valve grinding compound to keep the tool from slipping. I would use both heat and the compound.
I maintain Sikorsky helicopters for a living and I have a drawer in my tool box filled with tools to remove stuck fasteners. Left handed drill bits, ease outs, screw extractors and an air hammer to name a few. But when I use good tools and valve grinding compound, I don't have to open this drawer very often.

rajul

My Feedback: (58)

How does the valve grinding compound prevent slippage ? Just curious to find out.

old dog new tricks

My Feedback: (2)

By taking up extra space caused by the worn tool, or fastener. Also it gives alot more friction causing the tool not to slip as easily.