I have Honda 05' Rubicon with a few accessories, one being a jet kit. I came across a friend of mine with a bigger set of jets for mine that I could have. What can I expect from putting these in besides worse fuel economy? lol Should I do it?

 

you can expect a fouled spark plug.

 

Jet kits are made to fix a specific fuel problem. If you don't have a fuel problem or don't know the basic's of jetting, let it alone.

 

Have you ever checked your plug color? If not you need to make a full throttle run then shut it off and coast to a stop. Pull the plug and read the color. Black is rich, gray is lean. You want it to be a brownish black. More brown than black. If its gray or a white then a bigger jet would help. But if your already running rich its gonna kill your performance.