How do you make compression higher on Johnson outboard 85hp?

To increase compression on a Johnson 85hp outboard, you can start by ensuring that the cylinder heads are in good condition and properly torqued to specifications. You might also consider replacing the head gaskets with thinner ones to reduce the combustion chamber volume. Additionally, checking and potentially replacing rings or pistons can help improve sealing and compression. However, any modifications should be approached cautiously, as they can affect engine performance and longevity.