Slight knocking noise Johnson 5.5hp

Got an early '60's 5.5hp, runs relatively well with no major issues....except at low revs there is a noticable knocking or loud ticking noise. I can dial it out mostly on the high speed nozzle. I've checked to see if the coils are catching on the fly wheel and all seems ok even after ' re setting ' them. In the good old days it sounded like the engine was pinking but I'm not sure 2 strokes do this. Also when running at very low revs the magneto plate moves slightly and the cam opens the throttle linkage thus increasing the revs, only slightly though. Are the 2 faults connected ??

Check for loose wristpin / rod bearing.-------Recheck location of the coils.-----Not sure how the rotation of flywheel can cause magplate to rotate and open the throttle.

racerone said:

Check for loose wristpin / rod bearing.-------Recheck location of the coils.

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Now you mention it one of the coil heads looks slightly indented into the coil body but it seems nothing is actually touching/catching on the flywheel...will check again.

racerone said:

Check for loose wristpin / rod bearing.-------Recheck location of the coils.-----Not sure how the rotation of flywheel can cause magplate to rotate and open the throttle.

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I was thinking that if the magplate was not fixed securely and the flywheel was catching a coil ever so slightly, the rotation would cause the plate to turn, I've had once and adjusting the coils cured it. The throttle/tiller is very free moving, it almost feels loose but only moves at low revs when the cam is just touching the cam wheel.

Is the tapered friction piece installed inside the tiller grip ?-----The rotation of the flywheel would rotate the magplate and SLOW the motor down would it not ?

racerone said:

Is the tapered friction piece installed inside the tiller grip ?-----The rotation of the flywheel would rotate the magplate and SLOW the motor down would it not ?

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I'll check tomorrow...

Not sure now you mention it but the magplate and cam are moving slightly thus moving the cam wheel and the carb linkages hence the slight increase in revs..If I touch the magplate with my finger nothing moves and all is good. I've checked the linkages are set correctly and the cam wheel touches where it should and all seem in good order.

This "ticking sound"---Are you sure it is not normal sound for the motor? Outboards are not car motors. By comparison, are much noisier because they do not have heavy oil cushioning the plain bearings. Also, the pistons are much sloppier fitting. But of course, it could be worn. No way of deciding that from afar.

fdrgator said:

This "ticking sound"---Are you sure it is not normal sound for the motor? Outboards are not car motors. By comparison, are much noisier because they do not have heavy oil cushioning the plain bearings. Also, the pistons are much sloppier fitting. But of course, it could be worn. No way of deciding that from afar.

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It could well be and it seems likely. It's not a problem as such and it does dial out on the high speed jet. Thanks.