Turn the crank over to top dead center and check the valve clearance. Also check the plug, see what color it is. Plug checks will tell you alot if yuo know how to read them. Also check to see if the fuel cap vent is plugged and the fuel line. These are some areas to start. If the clutch slips, it could not be engaging correctly. Or they are just worn to far.
2004 KFX400,Yoshi 450 bbk, drze kit, drz flywheel, CWR pro-cams, Crasko P&P, custom Yosh header with FMF PC4, FCR39, ESR intake, Leager A arms, GTT modded 450r shocks, GTT rear link, Tag stem & bars, LSR axle, YFZ450 front calipers
2000 Lakota 300, DG excellerator,400ex carb,JB custom intake,Crasko P&P head CWR 335 kit and 390 cam, 400ex rear hubs, kfx400 front suspension, JB custom rear swinger.
Sponsors- JBcustoms, 6th Pinned Motorsports, Crasko Performance.