Announcement

Collapse
No announcement yet.

Stripped #5 Spark Plug - Looking for perspective

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    #16
    You didn't mention about drilling out the old threads before tapping; did you need to drill or just went straight to tapping? With drilling, it's hard to get the shaving with greased up drill bit due to drill speed. So it seems even with grease on the tap bit, there were greased up shavings dropped on the piston and it's hard to get them out with the sticky grease. I think it's hard to avoid the greased shavings dropping down. If this is the case, then maybe don't use grease at all then it's easier to vacuum the shavings out and blow the remain bits out of the EX valves. Did you turn the piston up near the valves before blowing the debris out? I would spend a fair amount of times trying to blow as much of debris out the opened EX valves and not hoping a running engine to do this task as there is a chance the shaving caught between the closing valves and the valve seats. You could do a leak down test on that cylinder to find out if it has leaking valves.

    Comment


      #17
      Originally posted by sapote View Post
      You didn't mention about drilling out the old threads before tapping; did you need to drill or just went straight to tapping? With drilling, it's hard to get the shaving with greased up drill bit due to drill speed. So it seems even with grease on the tap bit, there were greased up shavings dropped on the piston and it's hard to get them out with the sticky grease. I think it's hard to avoid the greased shavings dropping down. If this is the case, then maybe don't use grease at all then it's easier to vacuum the shavings out and blow the remain bits out of the EX valves. Did you turn the piston up near the valves before blowing the debris out? I would spend a fair amount of times trying to blow as much of debris out the opened EX valves and not hoping a running engine to do this task as there is a chance the shaving caught between the closing valves and the valve seats. You could do a leak down test on that cylinder to find out if it has leaking valves.
      FWIW when I have done timesert I’ve put the drill bit in the hand tap and drilled the hole. Slow and steady greased drill bit when doing it by hand might work to catch shavings.

      Comment


        #18
        Originally posted by sapote View Post
        You didn't mention about drilling out the old threads before tapping; did you need to drill or just went straight to tapping? .
        I did not do any drilling. The Time-Sert spark plug tool is designed to start in the existing (remaining) M12 threads in the cylinder head, which helps centering the cutting edges and keeping the tool aligned. Look back at the post with the tool pictured and the image should help. The standard metric tool kit (used in locations other than the spark plug hole) comes with a drill bit, the tools are shorter, and half the cost.

        These tools are very expensive ($250). Funny thing about the whole job is that it's a $1.70 part (the insert) that is all you need. And a new spark plug and coil is advisable.

        Similar but unrelated: different than the Time-Sert spark plug tool, when we found a lower shock bolt hole stripped on the trailing arm we used a Heli-Coil. That tool and process required drilling first, then rethreading and installing the heli-coil. And the tools was substantially cheaper.

        Comment


          #19
          About why the stripped threads, I guess someone had torqued the plug "to spec". I always am nervous when torqueing the plugs for this reason, and I just hand turned the plug until bottomed out, then torqued another 1/8 turns to crush the washer and done. For used plug, used less than 1/8 turns.

          Comment

          Working...
          X