1989 Honda FL400R Pilot Service Manual, Page 251Get this manual
TROUBLESHOOTING PROBABLE CAUSE 8Test cylinder compression COMPRESSION IS NORMAL COMPRESSION IS Worn cylinder and piston rings Blown cylinder head gasket Compression leak past crankcase
Faulty or deteriorated reed valve Piston rings stuck in piston
Low battery charge Damaged crankchah oil seal Clogged carburetor
Faulty carburetor Incorrect carburetor setting
POOR PERFORMANCE AT LOW AND IDLE SPEEDS
PROBABLE CAUSE
1Remove spark plug and try
spark test GOOD SPARK 2Check carburetor air screw
adjustment
WEAK OR SPARK
GO TO PAGE 16-2
3.Air is leaking past carburetor