Throttle nock?

[ahelbling33]

Hello all,

Hopefully someone can help me to figure out why I am having issues with a nasty "knock" when I throttle up my 2002 Merc 225 EFI on my 2002 Ranger 520. It just started doing this about 4 fishing trips ago in October. It doesn't do it every time, but seems to be better if the motor is at full operating temp. The "knock" about knocks you out of your seat and makes you cringe when it happens though. It feels like the throttle is grabbing way too hard or something? I am far from a mechanic, just hoping someone has some insight.

[EuropeanAM]

Please provide a better description.

One "clunk"... a series of knocks (like internal components failing), repetitive knocking related only to accelerating that goes away as RPM is achieved, etc (would be helpful information).

Any such knock should be investigated before continuing to run the engine!

[ahelbling33]

One jarring clunk as I engage the drive. It never does it while running, nor idle. Only in the initial transition from neutral to drive. I can hear it trying to engaging as I press forward and the WHAM, it engages all right, and it isn't pretty. Will knock a drink right out of your drink holder! I am thinking something may need to be adjusted to allow the drive mechanism to catch whatever it needs for the prop to engage completely. It's slippin then grabbin hard.

[EuropeanAM]

Andrew:

Two things need to be checked:

-Engine idle speed (IN the water, IN FORWARD GEAR). This is the ONLY appropriate condition under which idle speed should be taken (or adjusted, depending on engine serial number).

-Shift cable adjustment. Shift cable adjustment is CRITICAL.

Note: There are no "synchronizers" in the shift mechanism. It's a direct-drive engagement.

Hence, shifts should be made crisply in and out of gear (not "eased" in and out, as it causes undue stress and wear to the clutch dog and gears).

[ahelbling33]

I called OPC Marine today and they said problem could be shift cable adjustment and they would look at it. I will mention your other possible solution when I drop her off. Thanks for your help.