FaanP

How do you know it is time to replace your motor's bearings? I think I have to replace the bearings on my one motor but it is just a feeling - how can I tell for sure?

Flygio

Basically they become noisy. You could also experience some idle issues. And / or some axial play of the crankshaft with flywheel installed.

FaanP

They are not noisy .... and no idling issues. Feels a little rough when I turn the motor but my biggest concern is I can move my crank in and out - not up and down or from side to side. Any ideas?

Eivind E

You need to open the engine, remove the crankshaft and have a feel on the bearings with your finger. That is ultimately the only way to know for sure.

Most people are really afraid to open the engine, but it is nothing to be afraid of.
Just rotate the engine to where you know the piston is near top dead centre.
Then remove the four screws on the back plate, and carefully remove the back plate, and off you go.
It's not scary once you get going!

Then stick your finger in the bearing, and rotate it.
If it feels gritty, like it has sand in it, you need a new bearing.

And in any case, it is better to be safe than sorry! So just get some nice ceramics

blis

If you dont have the clutch on the engine with flywheel and collar secured it's normal for a crank to move in and out.

best pull engine, flush and clean bearings (with suitable solvent) and put your crank in. Inspect the seals, inspect rod connection, if you can feel it move up and down it's a problem. If not, lube the bearings with 1 drop of after run, put it back together and enjoy.

Bad bearings can wear into the engine's compression and pinch. it can allow air in and ultimately wear the crank and damage bearings even more...

U can often hear bad bearings in an engine.

FaanP

Thanks for the help