Almost stripped out spark plug hole

ugh.....

Apparently the guy I bought this bike from either A.) jammed these new plugs in and stripped out #3 spark plug hole or B.) was already stripping out and he jammed it in.

Either way, it is quite stripped. Through much patience, i was able to carefully get my #3 plug back in but it was not smooth and I am extremly worried now.

What is that piece of the engine called exactly on the bike where the plugs actually screw into? Is it possible to get that tapped to fix? If not or if so and it doesnt work, can you buy just that piece somewhere?

Regardless... my motor still wont start anyway.

 

That piece is called the cylinder head. It can be tapped with a sparkplug helicoil. Good thing about them is that they can be installed without pulling the head.

 

Wow, you're screwed! That's the cylinder head, the big finned part. It can be replaced with one from ebay or you can take it off and have the hole welded up with aluminum to fill in the missing thread area then retapped at a machine shop. You can also get Helicoils at auto parts stores to replace sparkplug threads and you can do that yourself without taking it off. That's the cheapest and easiest way but I haven't had good luck with Helicoils and I don't know how well they work holding against compression pressure.

 

is the helicoil something I can do myself? If so, like ArizonaSteve said, is there a risk that it won't hold the compresson? Is there like helicoil sealant you put it? Where can you buy helicoil, any auto parts store? I googled it but the results were all half @ssed.

 

Your local NAPA, Checker or Auto Zone should have the helicoils. They come with a tool to insert the coil. It's worth a try if the plug won't stay on it's own.
Stick a rag down inside the hole first to catch metal filings and pull it out afterwards and vacuum out the area. You don't want to get filings in the engine.

 

Helicoil makes an insert fut for sparkplugs. A regular helicoil will not work. Fastenall may have one also.

 

Take yer Moto to a decent Moto shop .Stripped spark threads are common and easily fixed with an insert. Simply Not worth it be that cheap.. let an expereienced hand with adequate tools/parts do it easily and actually qite cheaply.

 

Thanks, this is probably something I know I don't have the experience nor the tools to do properly. Compression is too important. I may wait until spring though since it is running great now but I love this bike and want to keep it around.

 

I've put a Spark Plug HeliCoil in: Yamaha, Honda, Triumph (750 Bonnie & TR-6), MGB, my 900, go-karts, lawn mowers and a chain saw.

They work GREAT! You save the head, the dough for an Off-On and all that time the bike would be down.

Get a talented mechanic to put it in for you. Leave the bike home. Stop somewhere close to where you live and find a pro who'll do the job for you.

Hang until he can get away to do the job. Drive him over. Get the HeliCoil in there. Drive him back. Stop at Duncan Donuts on the way back to his shop. Coffee and goodies on you!

Badda-Bing ... Badda-Boom!

 

Yea Helicoils while great, will need that tang part broken off at the end of the install and as such may not be useable for sparkplug holes. unless you have it sitting outside instead of assembled.
I'll do this though ...
Fill that chamber with diesel. And chase the threads. If you can, try to tap it to a larger size if sparkplugs are available in that size. If not, try cleaning the threads. The diesel will then have to be sucked out with a shop vac. repeat, and the more anal you are, more you'd repeat ... then finally repeat with oil, and of course drain and change the oil before starting the bike back up. Of course you can insert a drill with a cable extension and a small clean drill and agitate it through the plug hole. If you want to take off the crabs, take the manifolds off and set it to where intake valve is open so you can get more of a window into the chamber
If you do need to do a full on insert ... I'll drain the fluids take off most of the loose bits, and flip the bike upside down. Clean upside down, and raise the front wheel 4-5 feet. Here you'll generate more scrap metal and you'd want gravity with you. Then you'd tap it etc, then run fluid through it and get it out. Finally you may also want to turn it upright and run the fluids through it.
BTW in both methods, grease up the tool plenty with sticky sticky grease and tap it, you'd trap all the shrapnel in it instead of dropping it in the chamber. Then ofcourse flush flush flush ...
Cool.
Srinath.

 

By the time you did all that though, couldn't you have the head off and back on and know there's no swarf hanging around inside?

 

A Pro can put that coil in there with a greased-up tap (supplied in the kit) and have NO swarf get down into the chamber.

This should be a 20-minute job ... and it's done!

Before I'd do anything else other than just have a Pro do the coil job ... I'd swap the head ... or, the whole engine.

I have a whole 550 Parts bike. The engine is fine. For two-hundred bucks you can have the whole bike and the title. The carbs are worth close to that ... alone!

 

The cylider head can be repaired easily with the use of an insert. I have repaired many cylinder heads with the use of a time-sert. These are available at any automotive parts store such as Napa or Carquest. Check the following url http://www.timesert.com/html/sparkplug.html
I would not advise the use of a helicoil. These offer a more reliblae repair.

Good Luck

 

The piece of the engine is the "Cylinder Head"

The tapped holes for plugs: "Spark Plug Holes"

The very best possible solution to your problem is:

Have the stripped-out hole fitted with a HELICOIL. Have a PRO do it. An experienced professional can install the HeliCoil without any complications.
He'll run a greased tap in the hole. Collect all the swarth (shavings). Put the coil in and hand you the break-off tang for a souvenir.

HeliCoil's work GREAT! You save the head, the dough for an Off-On and all that time the bike would be down.

Get a talented mechanic to put it in for you. Leave the bike home. Stop somewhere close to where you live and find a pro who'll do the job for you.

Hang until he can get away to do the job. Drive him over. Get the HeliCoil in there. Drive him back. Stop at Duncan Donuts on the way back to his shop. Coffee and goodies on you!

 

Holy christ!!!

 

I know ... that was a wierd one! Very strange.

I kept reading it anyway ... looking for the part where he wanted you to mount the whole bike on a lathe.