Results 1 to 6 of 6
  1. #1
    RC Enthusiast
    Join Date
    Jul 2018
    Location
    Eugene Oregon
    Posts
    46

    3.3 Stripped Threads in the block

    Been slowly working on a friends T-Maxx with the 3.3 these last couple of weeks. It mainly needed the transmission rebuilt, or so I thought. After fixing that, found the stock exhaust needed replace because it was leaking at the seems, and the carb needed replaced (to much slop in the slide) and it would idle too high regardless of the idle screw adjustment. Replaced the carb and exhaust and gained a ton of lost power but still high idle regardless of the idle screw.

    Decided last night to pull the engine and check for leaks. Upon removing the ez-start system I find that one of the securing screws for the backplate to block just falls right out, here the threads for the upper right corner are stripped in the block.

    Has anyone else experienced this before? And what would be the best fix...an over sized screw of the proper length or just replace the block? It is of unknown age and an unknown amount of fuel through it, has been run hard 99% of its run time but is super strong yet with dang good compression, and the bearings still feel smooth.

    I didn’t have any issue keeping it in a tolerable temp range, with good smoke trails. Just would not idle right. I’ve come to the conclusion that the stripped backplate threads in one corner are causing the high idle issue.


  2. #2
    Marshal Double G's Avatar
    Join Date
    May 2008
    Posts
    12,773
    Replace the block - they can be had inexpensively w/the bearings.
    The Super Derecho

  3. #3
    RC Enthusiast
    Join Date
    Jul 2018
    Location
    Eugene Oregon
    Posts
    46


    The owner said he has another complete 3.3 that needs a rebuild so might just rebuild the other and run this one until it dies or move the internals over to the other block.

  4. #4
    RC Qualifier
    Join Date
    Dec 2017
    Location
    Van. Island British Columbia
    Posts
    429
    Not sure if it's worth it but I've drilled and put a Helicoil that flush mounts that has the same inner thread size in blocks for chain saws.
    Your drlling has to be pretty accurate and the block is drilled and tapped to the Helicoil OD while still keeping the OG inside diameter.

  5. #5
    RC poster
    Join Date
    Sep 2018
    Posts
    2
    I had the same problem, just replace the block it's a much easier fix...

  6. #6
    RC Enthusiast
    Join Date
    Jul 2018
    Location
    Eugene Oregon
    Posts
    46
    Quote Originally Posted by Rain Dawg View Post
    Not sure if it's worth it but I've drilled and put a Helicoil that flush mounts that has the same inner thread size in blocks for chain saws.
    Your drlling has to be pretty accurate and the block is drilled and tapped to the Helicoil OD while still keeping the OG inside diameter.
    I probably would have went that route if I still had a garage and drill press etc. Few more months and i’ll have my own garage again.

    I ended up using a screw that was slightly larger and so far it seems to be holding up fine. Darn little engine hauls like no other...im still new and my first nitro is my Rustler with a fresh pro .15
    Im already making plans for a 3.3 upgrade when this one hints for a rebuild.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •