Helicoil Aluminum Block

[dixiebonsai]

Anyone ever tried to helicoil insert in a briggs block? I was trying to get rid of the dreaded "new and improved" autochoke on a Briggs Quantum. Why do they always want to "new and improve" reliable , proven systems?My friend gave me the mower because thermostat on autochoke was sticking , causing it to only start when cold.I'm lucky he didnt take a hammer to it.If he stopped to go get a drink of water it refused to start until it cooled down.We ,as mechanics, all realize that it was flooding it because it was choking it when it didnt need choke.He was a non mechanic type.My redneck answer, rip all that $#^# off, put on primer bulb or throttle cable carb and away we mow.Well, thermostat is behind exhaust, to get it off I had to undo those bolts, like all exhaust bolts, heat had seized one.It sheared off.Now I realize I should have left it alone and just removed the arm and autochoke carb, Anyone have a procedure that helps seized bolt come on out so I dont do this again in the future?Ive tried welding a nut on stud couple of times, I'm down to very little stud left sticking out,afraid to try EZ-OUT, I'm sure that will break,then I wont be able to drill it out, so I'm left with helicoil.

 

[reynoldston]

I have used helicoids in aluminum blocks with good luck.

 

[motoman]

If you feel the machine is worth it and you can find a good local machine shop I recommend you pull the head and take it in. They will lock the head down on a flat drill or mill surface, and do a careful (hopefully) extraction. On the other hand you could do it (perhaps) if you have even a low end chinese floor drill press. IMO the critical thing is to lock down the head (jury rig some clamps) , make a good center punch dimple (perhaps the most difficult ), drill out the broken bolt to a shell without breaking out into the existing female threads and try an easy out, or LEFT HAND DRILL (HF has a little 4 pak). If successful, you can replace with original fastener. ( I know If, if, if...) Do no overheat that al head or it is scrap. And , as always, good luck.:thumbsup:

 

[bertsmobile1]

Quality manufacturers always put inserts into alloy as SOP.
Caveat is that a helicoil is not necessarily gas tight so you have to be a little careful.
Through bolts exposed to high crankcase pressure might leak a little.
However if that happens you can use a solid insert in place of the wire helicoil ( or equivalents ).
The precision of wire inserts is not particularly high so usually you can do them at home with a hand held drill .