You out there Rodbolt???
I have a 2001 Yamaha 250 OX66 with 225 hours. Well maintained and runs great. Unfortunately I have begun to notice a tapping / knocking noise at idle. It continues through the power band. Took it in to a dealer introduced me to the engine salesman even before he heard the motor run!
Disgusted, and decided to do my own diagnostics. I checked the following;
-O2 Sensor draw tube (carboned up, replaced it, but no fix)
-Lower unit
-Compression 110/115 all cylinders
-Max RPM 5200-5300
-No metal visible in the cylinders
-Plugs fine (some carbon but fine)
-Removed the plugs and using a dowel tried to move the pistons to check for wrist pin movement. Nothing.
I listened with a stethescope and it seems to be coming from the bottom of the engine perhaps louder in the lowest cylinder starboard side.
A couple questions;
-Rodbearing?
-Torsional Dampener?
-Carboned up since I don't use ringfree or yamalube?
-Would I do damage just to run it into the ground?
-Rebuilt or New motor
-I am a pretty decent backyard mechanic. Could I swap the powerhead myself?
Thanks for the input!!
I have a 2001 Yamaha 250 OX66 with 225 hours. Well maintained and runs great. Unfortunately I have begun to notice a tapping / knocking noise at idle. It continues through the power band. Took it in to a dealer introduced me to the engine salesman even before he heard the motor run!
Disgusted, and decided to do my own diagnostics. I checked the following;
-O2 Sensor draw tube (carboned up, replaced it, but no fix)
-Lower unit
-Compression 110/115 all cylinders
-Max RPM 5200-5300
-No metal visible in the cylinders
-Plugs fine (some carbon but fine)
-Removed the plugs and using a dowel tried to move the pistons to check for wrist pin movement. Nothing.
I listened with a stethescope and it seems to be coming from the bottom of the engine perhaps louder in the lowest cylinder starboard side.
A couple questions;
-Rodbearing?
-Torsional Dampener?
-Carboned up since I don't use ringfree or yamalube?
-Would I do damage just to run it into the ground?
-Rebuilt or New motor
-I am a pretty decent backyard mechanic. Could I swap the powerhead myself?
Thanks for the input!!