Engine shutter @ 1300-1500 rpm
 

Greetings to all forum members,

I've been fine tuning my 72 m117 engine for some time and due largely to the information obtained through this forum it's running allmost "perfect".
One running characeristic that I currently could use help trouble shooting is a slight but very noticable engine stumble/shutter between approximately 1300 and 1500 rpm.
You can feel the engine's power loss in this rpm range.



Thanks in advance for any and all replys.

Knarf

If the shudder is continuous during that rpm span I would think you are looking at a lean condition.

If the shudder happens as you pass through that range during acceleration my guess would be a plug wire end. if its plain intermittant but only at that rpm, I would look to the throttle switch (check the 20 accel enrichment steps as the throttle is depressed KOEO key-on,engine-off).

Tell us more about the conditions existing when in failure - a freeze frame so to speak.