Engine staring to sound like diesel RID

[Proboscis]

well after 5500km my lil bike is starting to wear down. great starter engine to learn on (bike + motor) i know it is loose rod bearing or maybe the carb but i will always like that little bike.

Have you tried to de-carbon the engine? It's pretty easy and with most people running an extremely rich 20/1 mix it's likely got a ton of carbon on the piston.

Remove your head, and turn the engine until it (the piston) is at the top. Use a wooden dowel or other piece of wood to remove the most of it, then finish it up with a brass brush. The kind that you put on a Dremel tool work great. DON'T use a scraper or screwdriver!

Use a shopvac to keep it all clean as you go.

It should help.

[Fox]

I would most certainly be interested to hear how a refurb goes.. rings/decarbonising etc etc

I hope to get a long life out of the engine, way more and 5k kms