diff --git a/crawl4ai/async_dispatcher.py b/crawl4ai/async_dispatcher.py
index b796a92b..64578bf6 100644
--- a/crawl4ai/async_dispatcher.py
+++ b/crawl4ai/async_dispatcher.py
@@ -317,7 +317,7 @@ class BaseDispatcher(ABC):
 class MemoryAdaptiveDispatcher(BaseDispatcher):
     def __init__(
         self,
-        memory_threshold_percent: float = 70.0,
+        memory_threshold_percent: float = 90.0,
         check_interval: float = 1.0,
         max_session_permit: int = 20,
         memory_wait_timeout: float = 300.0,  # 5 minutes default timeout
diff --git a/crawl4ai/async_webcrawler.py b/crawl4ai/async_webcrawler.py
index 6b919c11..929fa924 100644
--- a/crawl4ai/async_webcrawler.py
+++ b/crawl4ai/async_webcrawler.py
@@ -772,7 +772,6 @@ class AsyncWebCrawler:
         # Create default dispatcher if none provided
         if dispatcher is None:
             dispatcher = MemoryAdaptiveDispatcher(
-                self,
                 rate_limiter=RateLimiter(
                     base_delay=(1.0, 3.0), max_delay=60.0, max_retries=3
                 ),