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    MTN-9201 Spark Plug Insert – Measurements & Info

    Best price and more information on the MTN-9201 inserts at

    Best price and more information on the MTN-9201 inserts at

    Yes, we sell the MTN-9201 $18.99 or less. It’s a replacement spark plug insert that’s installed with the Mountain 9200 spark plug thread repair kit typically used on Ford 4.6, 5.4 and 6.8 liter engines with 2 valves per cylinder. The Mountain 9201 replacement spark plug insert is a stainless alloy steel insert that lasts the lifetime of an engine when repairing a spark plug hole from a blowout. Besides being over-sized, the MTN9201 has a patented lip that helps to repair oblong holes from a failed previous repair. The outside measurement of this lip is .85″ which is almost 22 millimeters.

    The outside measurement of the threaded part is .74″. The larger outside diameter makes this insert usable to repair spark plug holes when smaller parts store kits fail like Helicoil. The MTN-9201 also has the taper seat for the spark plug built-in to the insert. This way there’s no seat preparation tool needed to allow the spark plug to fit and seal properly. Unlike the Dorman spark plug fix, the MTN9201 accepts the original size spark plug which is a taper seat M14x1.25. We currently offer the best pricing on this spark plug insert at the MTN-9201 product listing on our website, You may also order on the phone by calling our toll free number at 800-734-8665.

    Ford dealers are some of our best customers!

    Ford dealers are some of our best customers!

    Brand: Mountain, manufactured by Horizon Tools. Notice our tier discount pricing for larger quantities.

    Outside measurement .74″ on outer part of threads, .85″ on O.D. of lip
    Patented lip makes sure there is no loss of compression.
    Permanent fix to damaged cylinder threads for spark plugs making the threads 10 times stronger than original.
    Replacement insert for the MTN9200 spark plug thread repair kit.
    Replacement spark plug insert for Ford engines 4.6,5.4 & 6.8 Liter 2V’s that have the typical “Blowout” problem.
    Used to repair damaged cylinder heads with blown spark plugs without removing the heads.
    Sparkplug insert size: M14x1.25 Taper seat insert for the Ford Cylinder Repair Kit (MTN9200). Packaged 1 insert per kit, in poly bag with label. Alloy steel insert.

    • Better than Helicoil.
    • Better than Dorman.
    • Professional, permanent repair.
    • Repair done right over the fender.
    • Oversize repair that fixes previously repaired holes.
    • Won’t back out on next spark plug change.
    • Tough, durable Stainless steel alloy that can withstand the heat and stress of the combustion chamber.
    • Similar properties to aluminum alloy.
    • Your questions answered when you purchase at!


    Comment from Mike
    Time February 25, 2016 at 1:25 am

    Concerning the Cal-Van 389-100 inserts, I see that there isn’t any threads at the top, does this mean that fully threaded spark plug can’t be used?

    Comment from Dennis Bandy
    Time February 25, 2016 at 7:05 am

    The fully threaded and partially threaded spark plugs both work in the MTN9201 inserts. If using a fully threaded spark plug the upper threads just won’t make contact. This way the insert works for either. If the insert was fully threaded it would not accept a partially threaded spark plug. The good news is that even though the inserts are not fully threaded they are steel alloy which is much stronger than aluminum, which is what the original threads are made of in the aluminum head.

    Comment from affilated auto sales
    Time October 12, 2017 at 5:08 pm

    does the mtn9200 kit have a threader

    Comment from Dennis Bandy
    Time October 12, 2017 at 6:12 pm

    Definitely. Here’s a link to the product listing that shows everything it comes with. MTN9200.

    Comment from kyle
    Time October 13, 2017 at 10:33 am

    does this kit have tap bigger than 14mm

    Comment from Dennis Bandy
    Time October 13, 2017 at 11:21 am

    Yes, M14x1.25 is the inside diameter. Outside is bigger.

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