Hey guys, My bro as a 400ex and that he bought not too long ago off of craigslist. It wasn't running good so we pulled ff the plug and it appears to be stripped. I figure we will have to take the head off an have it re machined or have a sleeve put in it and then re machined. any suggestions? also is there a way to keep the 18mm socket from grabbing the walls around where the plug goes in?
Thanks
Parker

 

If you have the plug out and look at the threads on the plug itself you will be able to see the threads and see if it is stripped. Something we like to do in the auto industry is to use heli coils for things like this. You might be able to re tap the threads, but I wouldn't recommend it since the shavings can wind up getting into the cylinder so its kinda risky. Usually you can put oil on the tap to chase the thread and hopefully gather all of the shavings, but like I said it isn't really recommended. Check to see if you can find a heli coil to match the threads and put it. Welcome to the forums. Also never use a regular socket when removing a spark plug due to the fact that you can crack the ceramic on the plug. There are special sockets for the plugs with a rubber insert or you can use the oem one that came with your tool kit.

 

About 4 ways to go if the plug hole is stripped.
#1. A new head
#2. A used head
#3 A insert like this insert
Do not use a heli-coil. Be there done that.
#4 Weld it up and retap it.

I would go for #2 or 3.

 

Hey Doctor turbo, could you resend that link of the insert? i cant open it. Also what is a heli-coil?

 

<div class="FTQUOTE"><begin quote>Hey Doctor turbo, could you resend that link of the insert? i cant open it.</end quote></div>
Neither can I. I don't know what the hell I'm doing wrong with these links. Try this one.
http://www.timesert.com/html/sparkplugAluminum.html

<div class="FTQUOTE"><begin quote>Also what is a heli-coil? </end quote></div>
A heli coil is a high carbon spring steel instert that looks like a tightly wound spring. The kit comes with it's own special tap and drill. I don't like them because I owned a bike that had one in it. The damn thing kept on unwinding when I took the plug out. For bolts they are better than great!!! I put in a zillion of them when I was an aircraft mechanic many lifes ago. But for sparkplugs they arn't so good.

For plugs the Timesert works super good but they arn't cheap so a used head may be a better way to go?

 

DR. T. I couldn't think of the other insert which you mentioned the timesert, but they are recommended over the heli coils. That's pretty awesome you were an aircraft tech I am currently in the process of going to school for a Ford Tech and leaning towards the diesel industry.

 

<div class="FTQUOTE"><begin quote>I am currently in the process of going to school for a Ford Tech and leaning towards the diesel industry. </end quote></div>
If your good you will make big bucks. You are smart going for the diesel mechanic
job IMHO.
A very good friend is a heavy eqip mechanic. He makes close to 100K a year!!! Real tough job and he gets beat up and works long hours but makes BIG $$$$'S.
Lots of mechanics out there, very few good ones though.
I admire you; you will do great in your new profession if you are smart.

 

Thanks for the good word and advice I really appreciate it. I am trying to get certified in as many things as possible that way I am more agile. It is alot of work, but I see around the dealership and no one wants to work on the diesels and I honestly really like them and don't mind the hard work since it's what I love to do. Is he with Cat or International that type of thing. Sorry for getting off topic on the thread by the way.

 

<div class="FTQUOTE"><begin quote>Is he with Cat or International that type of thing. </end quote></div>
He works with a big independent company that works on any machine. Mostly Cats though. They are a big Cat dealer.
You sound very smart for doing this. You will make big bucks if you stick with it and like the work. Good luck.

 

Thanks again Dr turbo. Looking at your pics and you racecar was that a eutectic piston that you fried.