Stripped Spark Plug Hole,,, what do you do with the chips?

Top End (cylinders pushrods etc.)
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foundationapps
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Stripped Spark Plug Hole,,, what do you do with the chips?

#1

Post by foundationapps »

Hi all,

Shoulda caught this when I had the head off, but didn't. Used a plastic rifle cleaning brush to clean out plug holes, and found some damaged threads. Immediate forehead wrinkle... Going to do a spark plug hole repair (STD head), question is, what is the best way to extract the inevitable chips that don't come out with the tap?

Read that you blow them out, but that's GOTTA miss some, shop vac and suction them all out?

Any suggestions?

Respectfully,
Trig
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#2

Post by RUBONE »

Coat the tap with grease and the chips stick to it. That trick has been around since before Harley and the Davidsons...
foundationapps
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#3

Post by foundationapps »

Simple is excellent!! Thank you sir. I way overcomplicate things.
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#4

Post by Andygears »

Shop vac with a small nipple don't hurt after. Probably best to work with piston at about top dead center.
I did a 800 honda once with rusted plug that snapped off, rusted solid, left just the thread. Patience was key, picked out thread one loop at a time, used small magnet and shop vac to cleanit out after retapping with greased tap. Was successful.

andygears
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#5

Post by foundationapps »

Andy... Great point on the TDC piston. Would not have thought of that one. Much appreciated.

Respectfully,
Trig
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#6

Post by Mark44 »

Andygears wrote:Shop vac with a small nipple don't hurt after. Probably best to work with piston at about top dead center.
I did a 800 honda once with rusted plug that snapped off, rusted solid, left just the thread. Patience was key, picked out thread one loop at a time, used small magnet and shop vac to cleanit out after retapping with greased tap. Was successful.
And one of those remote inspection cameras would be useful here just in case a chip or two fell in.
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#7

Post by Andygears »

That honda was a bit easier than a big twin. Vertical cylinder and flat top piston and mostly steel chips from remains of the plug. Grease on the tap, one or two turns, remove,clean, repeat, should be fine. Then a helicoil? be careful not to lose the tang, buy the kit with the tap & coils. I prefer to stop short of tapping thru & shorten coil from top to just below surface, then when happy with insert, ding the aluminum enough to stop coil from backing out. Patience is the key, good light, measure depth of thread, length of coil, length of tap, lead (unfinished threads) on tap. Consider, think, plan and do it right the first time. If you muss it up, second chance means pull the head.

my two cents
andygears
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#8

Post by james »

Back in the day stripped spark plug holes were common on VW's. We would install Inserts into the cylinder head. After tapping out the hole with a special tap with grease on it to capture most of the aluminum filings, we would start the engine with the damaged hole open, running on 3 cylinders.
Whatever fell into the engine if anything was blown out. Made a hell of a racket running the engine with a plug hole open. Installed a spark plug insert and all was good. Never had a problem. I can't see soft aluminum filings causing a problem. Try kicking the engine over a few times after you tap out the threads. I would lower that piston before tapping too.
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#9

Post by Buddhahoodvatoloco »

Kewl little suggestion on running it open, kewl as %^ck. All the suggestions are valid, matter of interpretation, and implementation, patience. Patience..
james wrote:Back in the day stripped spark plug holes were common on VW's. We would install Inserts into the cylinder head. After tapping out the hole with a special tap with grease on it to capture most of the aluminum filings, we would start the engine with the damaged hole open, running on 3 cylinders.
Whatever fell into the engine if anything was blown out. Made a hell of a racket running the engine with a plug hole open. Installed a spark plug insert and all was good. Never had a problem. I can't see soft aluminum filings causing a problem. Try kicking the engine over a few times after you tap out the threads. I would lower that piston before tapping too.
Jim M
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#10

Post by foundationapps »

Hi all,

Just wanted to wrap up how I handled this one. Was cutting new threads for the steel insert. I became convinced that some chips escaped into the head. Said the heck with it and removed the head, yep, some chips had escaped right next to the rings and had invaded the airspace on top of the top ring,,, so.... I decided the cylinder had to come off next. Another, "i've never done this one before moment." This project has become alot of those... I'm loving it. SO.... I decided the heads should be matching, and the front head with the good threads wasn't torqued down yet, I removed the front head and put a steel insert in that head too. Glad I did it.

It was during the cylinder replacement that I decided to try the manual timer, now the timer won't come off this engine without the front head being removed (STD heads, the STD people said it would be ok to grind some clearance on the fins so that the timer could come out with the head in place.... Yep, not going to happen, my pay grade stops before I cut down cooling fins on an STD head).
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#11

Post by Lowbikemike »

If you take the timer head off you might get enough room to remove the timer without removing fins. Not sure how the STD heads differ.
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#12

Post by Bigincher »

I think you were wise to remove the head. Good choice, I'm not sure everyone would've done the prudent thing. And now you never have to worry about where those chips are and what they're doing.
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Re: Stripped Spark Plug Hole,,, what do you do with the chips?

#13

Post by foundationapps »

Thank you sir for agreeing with that move to remove the head, then just did them both so they're the same, that's probably the Jumpmaster side of me coming out. Pairs are better than single setups.

LowBikeMike, About the STD heads shape. I tried that, but the cooling fins on the STD heads still interfere with the stripped down timer. I posted pictures of the STD vs. the original 48 head that I still have. Bigger cooling capacity on the STD. I had to lift the head about 1.2", using three bolts to stabilize the drift of the head, until the timer would clear.

So, my call is to put new points and condensor on the old manual timer, and go original with that setup. If it takes a crap, I know how to pull the head and redo that. This new frame has 2" of up stretch in the backbone, so there is plenty of clearance to work the head(s) off the bike in the frame. Probably easier to work on in the frame as I can strap the entire bike down and get good torque on the head bolts without having to leg wrap the engine and stand on the living room floor :)

Respectfully,

PS, for comparison, the STD head is the bottom head in all three pictures,
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