1974 Johnson Seahorse 4hp Clicking/Grinding Noise

[jac25]

A few months ago, I purchased this engine. For the first 6 or so times using the engine it ran well, aside from requiring a large amount of pulls to get it started when cold. But recently, it has begun making a clicking/grinding noise at all speeds, similar to those made in the attached video. Any ideas on what could be the cause of these noises and what I could do to resolve them?

Thanks

 

[Chinewalker]

Sounds like it's running a bit rich at speed. Hard to hear any clicking, but if it is there, try rotating the flywheel by hand and feeling for any rod slop. Lots of those 4s got run a 50:1 fuel ratio, but I am of the opinion that the babbit bearings inside like having a little extra oil in the mix. Might have worn connecting rod to crankshaft bearing surfaces.

 

[oldboat1]

Make sure there is oil (clean oil) in the lower unit, as the motor is new to you -- would replace the impeller while at it.

Might check the starter recoil for rattles, and wouldn't hurt to pull the flywheel and make sure all is tight.

 

[jac25]

Thanks for all of the input, I really appreciate it. When I turn the flywheel by hand, the noise seems to be coming from the power head area, not sure if that's of any help. Thanks again.

 

[oldboat1]

Could be some internal wear, like Chinewalker suggests. If it were mine, I might try running it on a richer mix (24:1, or something between 24:1 and 50:1). No point in fouling plugs, but might see how it runs on a richer mix.