Hi, i own a 2012 Road King with approximately 20,000kms, I bought the bike from a dealer in QLD at 12,000kms, have changed the oil twice in this time as it was apparently serviced at time of sale, my problem is now that i want to change plugs the rear plug will only unscrew about half way till it seizes and will not unscrew further, now, I dont want to use a breaker bar on it obviously, any recommendations on how I can remove the plug. I have no idea what the dealer did but it aint coming out without some major persuasion and or damage to the head. The front plug came out easily and was still in very good condition, the plugs are HD ones, probably from factory, and have slight rust aroung the metal base of the plug, any suggestions would be greatly appreciated, BEFORE I am left with no alternative but take it back to the dealer.

 

Cheers

Rosscoe

Spray with some CRC or WD40 and leave over night.

Thanks Allde, never had a problem with a seized plug before, in any previous Harley is this a common problem in the later Harley's or am i just lucky?

get your bike hot and use CRC on the thread and try and wind the plug back and forth slowly working it out

Reckon you're just lucky.

Allde's on the wright track, CRC, WD40 or one of the many release agents that are on the market.

Screw the plug out as far as it comes easy, apply the stuff, then slowly and gently screw in and out to work the stuff in.

You'll soon tell if you're making way.

If it isn't coming any further, like Allde says, soak it overnight and try again next day.

If that lot don't shift it then you're prolly better to get things squared away with the dealer in case things get bad.

Good luck.

(posted over Ando,,,he's right, run it till it's hot first.)

tighten it back up and spray it with wd40. unscrew it again to the point where you feel its too tight and spray it again with wd40. screw it back in a bit and spray. screw it back out again until you think its too tight and spray again. repeat steps 1 2 and 3 about fifteen times and you will gain a little bit each time. you might have to do it 100 times so use a ring spanner (saves you fuckin around with the ratchet and you get a better feel with the spanner) be patient with it. if its still tight after 100 twists and turns, ignore the compulsion to put the breaker bar on and wring its fukin neck.

What??

Thanks guys, yeah going to spend today playing with it, hopefully it will work its way out and wont need to take it to the dealer to rectify this, hate spending money taking the bike to dealers when it is something I usually do myself and is normally just a simple service, never had a seized plug before, car or bike.

A machinist might be a better place to take it.
Dealer might just talk you into new heads.
Arnt they only parts replacement and service mechanics anyway.

If its really stuffed you probably need the hole drilled out, re tapped and hellicoiled to suit the standard plug.

Hi there

Better than CRC or WD40 although those products work is a product supplied by Wurth called Rost OFF. It's far superior to both those lubricants and will definitely help. But as all the other posters have suggested take your time and hopefully you'll get a win.

If you do succeed would be a good idea to run a chaser through the plug hole thread to clean it up. Bit like using a tap. They're available at most tool places for a 14mm and 18mm plug in the one tool.

 

Cheers

conmore and the other post are correct , there are superior releasing agents you can use, a bit at a time as others have said and then use a spark plug thread chaser with a bit of grease on the tap so as to get the alloy to stick to it so any shavings wont drop into the cylinder. as kiwi dave also said use a small amount of high temp never seize on your threads and don't over tension the plug when you refit it . The reason the plug is in the state it is, is more than likely due to being over tightened. lf youre not confident seek out some one who is, good luck

Thanks to everyone for all the suggestions, well an update, after soaking the plug recess last night I went out this morning and spent the first few hours undoing bit by bit, must have done it a hundred times, unscrew then screw back in then, well you get the drift, all of a sudden she let go, BUT NOT IN A GOOD WAY, have spent the rest of the day stripping the bike down to remove the head, the plug snapped flush with the head and dropped the porcelain and metal bit into the cylinder, what a pain in the arse. Now having trouble getting the rocker box off, rocker cover is off and all bolts and rocker arms have been removed, push rods out, injection system and exhaust removed, got to remove the rocker box to get to the other head bolts. Any suggestions on the rocker box, have tapped it with a piece of wood, GENTLY, still not moving, becomming a little annoyed now LOL.
I think whoever put the plugs in used an impact gun............At least am learning the ins and outs of my bike LOL.......

Well that's a pain in the arse Rosscoe, as mentioned above when you insert your new plugs use a dab of Copper coat / Never Seize.

I feel your pain mate. don't have any advice on the rocker box except brute force and ignorance

Patience and brute force got the rocker box off and the head came off by hand, now just gotta get the plug out, new gasket kit and put her back together and shes a goer again, oh yeah gotta buy plugs as well AND ANTI SEIZE LOL

Just as well I bought the Premium Harley davidson Tool Kit, would have been lost without it.

Thanks for everyones help

 

try the new plug in the hole BEFORE you bolt the head back on.
by the sounds of it over use of loctite comes to mind

Yeah mate, the only thing the tool kit didnt come with, she's only done 20000 but the plugs have never been changed since factory by the looks of them, the air filter hadn't been looked at either, was told she had been serviced just prior to purchase. You would think dealers would look after their own bikes a little better than this. Gotta take the head in and have the plug drilled out and probably helicoiled. Hard to understand the factory using that much loctite, if of course that is what they did. MAYBE this bike is not what it seemed when we bought it. HOWEVER it has been great so far until now of course, it took us to Yamba on the NSW Nth Coast, and to Sydney from QLD, both times towing a trailer, averages 4.8-5.2Litres per 100, towing the trailer using cruise control and sticking to the speed limits.

You may not want to hear it, but think very hard about repairing both heads .
Look for someone that uses Time-sert's .

the loctite reference was to the rocker bolts not the plug

LOL......I would love to see Locktite on a sparkplug thread. Mind you it gets so hot there that it would not work anyway.