Spark plug stuck??
Road Warrior
Joined: Jun 2017
Posts: 1,705
Likes: 1,017
From: Lawrenceville Ga.
John's right, I work on military contract parts and every one made with aluminum requires helicoils or insert / PEM in all threaded holes.
The helicoil actually increases the contact area just as if it's a bigger screw and if installed correctly will not easily fail.
Use a piece of clean linen about 6" square, lightly grease it up and slide into spark plug hole. Also grease your drill and tap to catch chips.
Then use tweezers to remove the cloth and capture pretty much all the chips.
The helicoil actually increases the contact area just as if it's a bigger screw and if installed correctly will not easily fail.
Use a piece of clean linen about 6" square, lightly grease it up and slide into spark plug hole. Also grease your drill and tap to catch chips.
Then use tweezers to remove the cloth and capture pretty much all the chips.
Road Warrior
Joined: Jun 2017
Posts: 1,705
Likes: 1,017
From: Lawrenceville Ga.
Banned
Joined: Dec 2014
Posts: 21,413
Likes: 18,030
I had an old VW that the plug blew out of the head. They fixed it. Might cost 2 hours labor at most
Club Member
Joined: Mar 2009
Posts: 66,102
Likes: 51,359
From: Niles Canyon Ca.
You do pull the head look for a time sert or similar solid insert kit, these are made so once you seat the insert you can swedge the threads inside the combustion chamber with the flare tool so they won't seize and back on you like a helicoil is prone to doing. Head on clean the new oversized threads with acetone before putting the insert in and use high temp loctite 272 on the new insert, install and seat fully and let sit overnight to set up fully.
Compressed air with a skinny nozzle stuck down the hole will blow out and shavings that may have dropped but don't sweat it or over think this part, it's aluminuim so it won't hurt the rings or cylinders walls and the first 3 seconds running will blow anything in there out anyway.
Last tip you try this yourself I use a wax base tap lube and just load the tap up, it catches 99% of the chips when you cut the new threads.
Amazon has everything for this job.
Club Member
Joined: Mar 2009
Posts: 66,102
Likes: 51,359
From: Niles Canyon Ca.
40 odd years as bike mechanic and I've never seen this fix itself or be ok, it just moves the timing of the repair is all.
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Seasoned HDF Member
Joined: Jun 2014
Posts: 5,448
Likes: 6,275
From: pacific northwest
curious, is this the first time the plugs have been removed? in my younger days I stripped my share of plug threads but never had one do as you had happen. wondering if this happened when the bike was assembled?
Seasoned HDF Member
Joined: Aug 2006
Posts: 24,423
Likes: 30,643
From: Pennsylvania
The spark plug torque on the newer models is 89-133 inch-lbs and the HD Service Manual calls for anti-seize on the plug threads.
Last edited by CoolBreeze3646; Oct 15, 2020 at 09:17 PM.