Author Topic: Broken Spark plugs in head  (Read 491 times)

Offline Drew Back

  • A's Best Friend
  • ***
  • Join Date: Jun 2014
  • Posts: 172
  • Karma: 0
Broken Spark plugs in head
« on: 13.04. 2015 02:28 »
I have this A10 head I was stripping down and I seem to have broken both plugs off in the head they are rusted solid..I tried drilling them out and wont budge at all..I dont want to damage the threads any other ideas???I tried busting them out with a punch but again im to close to the threads..

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: Broken Spark plugs in head
« Reply #1 on: 13.04. 2015 03:29 »

 Just had a look for it but can't find- a few months ago, I think it was Olev posted suggesting a 50/50 mix of acetone and ATF, to which I keep meaning to add my mixed (....the odds be 50/50) results . Try that and see, but stock up on cold drinks cos it takes a while. ..I have a 2" pipe cutter that had a seized citing wheel.
 I'd tried all the obvious things to no avail, but as soon as I read the post I did it, and after a few weeks, the wheel was free. .. trouble is the acetone evaporates fairly quickly when the air is warm, and as someone else noted the two don't mix readily- may depend on the brand of ATF...! That's about the best I can do.
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline WozzA

  • Wise & Enlightened
  • *
  • Join Date: Nov 2011
  • Posts: 1307
  • Karma: 16
  • Melbourne Australia
Re: Broken Spark plugs in head
« Reply #2 on: 13.04. 2015 08:23 »
You could try heating the head ( in oven or BBQ ) as you would to remove valve guides & a easy out..
'51 Golden Flash Plunger
'57 Golden Flash Swingarm

Melbourne
The biggest lie I tell myself is
"I don't need to write that down, I'll remember it"

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5479
  • Karma: 64
Re: Broken Spark plugs in head
« Reply #3 on: 13.04. 2015 08:39 »
As WozzA says heat the head, and if you've made a hole in the plug body squirt in some of that plumbers Freeze spray into the plug, might help shrink the plug a little.
never used this spray myself so don't know if it spits or misbehaves in any way soead the can maybe
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline stu.andrews

  • A's Best Friend
  • ***
  • Join Date: Mar 2012
  • Posts: 138
  • Karma: 4
Re: Broken Spark plugs in head
« Reply #4 on: 13.04. 2015 11:45 »
Have heard that Coke (the drink, not the other kind) can do it but have never had to try it.
Has anyone else tried it?
2010 Yamaha TDM 900-Touring
2012 Triumph Bonneville SE-Fun


Offline Drew Back

  • A's Best Friend
  • ***
  • Join Date: Jun 2014
  • Posts: 172
  • Karma: 0
Re: Broken Spark plugs in head
« Reply #5 on: 13.04. 2015 15:03 »
Well I got them..I step drilled up to 15/32 then pounded a large bolt though to take out what was left and used a thread chaser looks good as new..What a relief!!!!!!!!!Now off to the welder to fix the broken fins I now have when the head flew off the bench when drilling.....Make sure when drilling a head you have it completely fastened down..Lesson learned......

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5077
  • Karma: 48
Re: Broken Spark plugs in head
« Reply #6 on: 13.04. 2015 15:17 »
Glad you were successful. Sorry about the fins.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

Offline muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8333
  • Karma: 107
  • Lithgow NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: Broken Spark plugs in head
« Reply #7 on: 13.04. 2015 20:34 »
Bugga.
A pair of sliding clamps are the most used tool on my bench.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7