Bike does not start.

• Check compression.

• Check spark. Note that sometimes plugs can show spark but don't perform while under compression.

• Check timing.

• Check for known good battery. Note: Many bikes (especially 79-83 Honda DOHC 750/900/1000/1100/CBX) absolutely require a hot battery just to start much less run good.

• Spray starting fluid down bore of carb with air filter and/or air box removed. It should at least try to get running.

Bike tries to start but does not run on it's own or run long.

• Test ignition system.

• Intermittent cylinder response? Swap coils or ignition modules to see if the problem follows the change.

• Check fuel flow from the tank by removing the fuel hose from the carb.

• Spray starting fluid down bore of carb with air filter and/or air box removed. If this changes things it is definitely the carburetor and should be serviced.

Bike leaks fuel.

• Floats don't float.

• Float/Fuel level too high.

• Float valve not sealing against seat.

  • Worn Needle

  • Worn Seat

  • Seat not sealing against body

  • Weight of fuel above over rides spring rate of needle's spring. (Common problem related to OEM Vacuum petcocks. We have the solution for this)

  • Trash in fuel keeping needle from sealing against seat (Clean tank, and replace/install fuel filter)

• Floats have mechanical bind on pivot or are hitting walls.

• Fuel tees not sealing. (We make them)

• Leaky bowl gasket.

• Bowl drain screw and or seal not sealing.

• Corroded bowl/body.

Hanging Idle. (Vacuum leak)

Note: To check for these use WD40 with the engine running to spray around these areas until a change in RPM is found. Once noticed pinpoint the leak and replace/repair component. (The WD40 clogs the leak till it gets sucked into the intake tract.)

• Cracked, loose, hard and mis-configured intake manifold boots, carb holders etc.

• Leaky butterfly shaft seals

• Torn or cracked vacuum hoses to petcock etc.

• Leaky vacuum petcock diaphragm.

• Tight Exhaust valve.

Wont Rev!

• Check for known good battery. Note: Many bikes (especially 79-83 Honda DOHC 750/900/1000/1100/CBX) absolutely require a hot battery to rev.

• Charging system should be putting out 13.5 Volts DC at the battery at midrange. The charging system should actually put out around 14.7 VDC before the voltage rectifier shunts to ground as too much voltage would cook the battery. If the battery is not seeing (or able to hold) this voltage it may not have enough volts to send to the ignition system to keep up with the RPM demand, and requirements of an electronic spark advance unit.

• Carburetor dirty

• Carburetor not jetted for some changes in:

  • Altitude. Decrease main jet size one size per 2000' above sea level.

  • Exhaust

  • Intake.

• Fuel flow requirements not being met.

  • Too small a float seat

  • Partially clogged or undersized fuel filter

  • Trash in fuel delivery system. (Petcock, Tank fitting, Hoses, Fuel Tees, Filter)

  • Float/Fuel level too low.

Wont Idle!

• Carburetor dirty.

• Pilot circuit not jetted for some changes in:

  • Altitude. Decrease pilot jet size one size per 6000' above sea level. The pilot or air screw can be used for fine tuning increments less than this.

  • Exhaust

  • Intake