My engine lost power above 3500 rpm and would not get over 4000 without dropping back down.<br /><br />I checked the fuel lines and filter and replaced the plugs.<br /><br />The problem was still not fixed so I pulled out the plugs and the number 5 plug looked almost like it just came out of the box.<br /><br />Only black on the very tip and clean otherwise.<br /><br />I plan on pulling the bottom carb and checking it out, but what else could cause this?<br /><br />Should there be oil on the plug even if no gas is getting through?<br /><br />Thanks.