diff --git a/icu4c/source/test/intltest/lstmbetst.cpp b/icu4c/source/test/intltest/lstmbetst.cpp
index cbeaadf..7281a37 100644
--- a/icu4c/source/test/intltest/lstmbetst.cpp
+++ b/icu4c/source/test/intltest/lstmbetst.cpp
@@ -28,8 +28,6 @@
     TESTCASE_AUTO(TestThaiGraphclust);
     TESTCASE_AUTO(TestThaiCodepoints);
     TESTCASE_AUTO(TestBurmeseGraphclust);
-    TESTCASE_AUTO(TestThaiGraphclustWithLargeMemory);
-    TESTCASE_AUTO(TestThaiCodepointsWithLargeMemory);
 
     TESTCASE_AUTO_END;
 }
@@ -249,48 +247,4 @@
     return engine.orphan();
 }
 
-
-void LSTMBETest::TestThaiGraphclustWithLargeMemory() {
-    runTestWithLargeMemory("Thai_graphclust_model4_heavy", USCRIPT_THAI);
-
-}
-
-void LSTMBETest::TestThaiCodepointsWithLargeMemory() {
-    runTestWithLargeMemory("Thai_codepoints_exclusive_model5_heavy", USCRIPT_THAI);
-}
-
-constexpr int32_t MEMORY_TEST_THESHOLD_SHORT = 2 * 1024; // 2 K Unicode Chars.
-constexpr int32_t MEMORY_TEST_THESHOLD = 32 * 1024; // 32 K Unicode Chars.
-
-// Test with very long unicode string.
-void LSTMBETest::runTestWithLargeMemory( const char* model, UScriptCode script) {
-    UErrorCode   status = U_ZERO_ERROR;
-    int32_t test_threshold = quick ? MEMORY_TEST_THESHOLD_SHORT : MEMORY_TEST_THESHOLD;
-    LocalPointer<const LanguageBreakEngine> engine(
-        createEngineFromTestData(model, script, status));
-    if (U_FAILURE(status)) {
-        dataerrln("Could not CreateLSTMBreakEngine for " + UnicodeString(model) + UnicodeString(u_errorName(status)));
-        return;
-    }
-    UnicodeString text(u"อ");  // start with a single Thai char.
-    UVector32 actual(status);
-    if (U_FAILURE(status)) {
-        dataerrln("%s:%d Error %s Could not allocate UVextor32", __FILE__, __LINE__, u_errorName(status));
-        return;
-    }
-    while (U_SUCCESS(status) && text.length() <= test_threshold) {
-        // Construct the UText which is expected by the the engine as
-        // input from the UnicodeString.
-        UText ut = UTEXT_INITIALIZER;
-        utext_openConstUnicodeString(&ut, &text, &status);
-        if (U_FAILURE(status)) {
-            dataerrln("Could not utext_openConstUnicodeString for " + text + UnicodeString(u_errorName(status)));
-            return;
-        }
-
-        engine->findBreaks(&ut, 0, text.length(), actual, status);
-        utext_close(&ut);
-        text += text;
-    }
-}
 #endif // #if !UCONFIG_NO_BREAK_ITERATION
diff --git a/icu4c/source/test/intltest/lstmbetst.h b/icu4c/source/test/intltest/lstmbetst.h
index 8958c5f..da6f86d 100644
--- a/icu4c/source/test/intltest/lstmbetst.h
+++ b/icu4c/source/test/intltest/lstmbetst.h
@@ -35,13 +35,10 @@
     void TestThaiGraphclust();
     void TestThaiCodepoints();
     void TestBurmeseGraphclust();
-    void TestThaiGraphclustWithLargeMemory();
-    void TestThaiCodepointsWithLargeMemory();
+    void runTestFromFile(const char* filename);
 
 private:
     const LanguageBreakEngine* createEngineFromTestData(const char* model, UScriptCode script, UErrorCode& status);
-    void runTestFromFile(const char* filename);
-    void runTestWithLargeMemory(const char* model, UScriptCode script);
 
     // Test parameters, from the test framework and test invocation.
     const char* fTestParams;