...drilled out frozen plug?

I have found yet another prospect. Posting said "partially restored, still needs some work".

After my initial inquiry of "what was done, what still needs done" he responded:

"Chrome was shined back up, frozen plug drilled.out of head and retapped. Twin straight pipes cleaned up, gas tank cleaned out, newer cables. Prob cost about 300 to get it on the.road.


Thankfully, I have never dealt with any frozen plugs. That being said, what could this effect? How does one drill and re-tapp a head without having to step up to a larger thread diameter?

This seller is motivated to sell because he has to move to Texas. Also has an 850cc, 70's, yamaha "chopper"(presumably an XS) that I inquired about. Said he'd give me a deal on both...

 

Drill the Stud remnant Drilled out and repair the Threaded Hole with a "HeliCoil" or some other popular Thread "Insert"

:Or:

Have the remnant Drilled-out and the Hole filled-in with a carefully applied Weld.
The Welded repair -- Dressed.
The Dressed repair -- Drilled and Tapped anew.

I Broke an Intake Manifold Stud-hole.
I needed the Head repaired.
They "Burned-out" a Broken-off EZ-Out and Stud remnant.
Filled the Hole.
Built-up the "Ear" where the Hole is drilled.
Used a Gasket to Outline the Manifold shape for Machining.
And, ... reshaped the Manifold like new.
$275.00 Winter work. Cash.

 

As many bikes as are out there that haven't been cobbled or hacked, I'd be very wary. There are a number of different products for repairing spark plug holes; done correctly most are very effective. Done correctly. If this bike doesn't run, get a compression test at very least. You didn't say what it is?

 

When getting mine out of it's 15 year suspended animation (oxidation never sleeps) it had 4 stuck plugs. At th time i didn't want to take th head off, so i did them insitu and put in helicoils. With carbs and pipes off a combination of compressed air, vacuum and valve timing to suck/blow th debris out of th cylinder with an extra filter added to th vacuum to see what was coming through. Once i could get nothing in the filter i put in new plugs with some anti seize, 12,000 kms ago. If doing it again i'd take th head off.

 

For Spark Plug Holes:

This Kit (and the one like it from AutoZone) will do the trick without removing the Head.

http://www.amazon.com/Perma-Plug-1-25-S ... B0025PMJHA

Follow the directions to the letter.
GREASE the Tap.
The Swarf will be collected in the Grease at the Flutes.

Tap the Hole half-way.
Clean the Tap of Grease and Swarf from Tapping.
Re-Grease.
Finish cutting New Threads.

Clean and DRY the New Threads.

To Install the New Threaded Liner.
Spray the Threads of a NEW Spark Plug with WD-40
WRAP the Plug Threads with two layers of Teflon Thread Tape.
Smear the Teflon Taped Threads with AntiSeize Compound.
Thread the Plug into the New Insert.
Apply PERMANENT Thread Lock to the OUTSIDE of the Insert.
Apply PERMANENT Thread Lock to the New Threads in Spark Plug Hole.
Install the Sleeve and Plug, ... using the PLUG as an Insert Tool.

Torque to Specs.
Let the Thread Locking Agent Cure
Remove the Spark Plug.
Stake the Insert with Tool provided.

Remove Tape from Plug or Insert.