TILLOTSON HU Series - Service Manual

Questions and Answers

T
Theodore SmithJul 28, 2025
What to do if my TILLOTSON HU Engine will not accelerate?
- K
  Kathy SellersJul 28, 2025
  If your TILLOTSON Engine won't accelerate, it could be due to several reasons. The idle mixture might be too lean, requiring a readjustment. Alternatively, the diaphragm lever might be incorrectly set and needs resetting. Check if the diaphragm cover plate is loose and tighten it if necessary. A leaking diaphragm gasket could also be the cause, in which case you should replace it. Finally, the main fuel orifice might be plugged. To resolve this, remove the diaphragm cover, diaphragm, diaphragm lever, and high-speed mixture screw, then clean out the orifice by blowing through the high-speed mixture screw threaded hole.
E
Erika SalazarAug 3, 2025
Why does my TILLOTSON Engine run out lean?
- H
  Heather WilsonAug 3, 2025
  If your TILLOTSON Engine runs out lean, it could be due to a few potential issues. First, check the tank vent to ensure it's operating correctly; clean it or replace it if necessary. Second, inspect the fuel system from the tank to the pump for any leaks, and tighten or replace fittings or lines as needed. Third, a ruptured fuel pump diaphragm could be the culprit, requiring replacement. Lastly, a plugged main fuel orifice can cause this issue, so make sure to clean it.
N
nwarnerAug 9, 2025
How to fix a TILLOTSON HU that will not idle?
- K
  Kayla CurtisAug 9, 2025
  If your TILLOTSON Engine will not idle, consider the following potential causes and solutions: * Incorrect idle adjustment: Reset to the best idle. * Clogged idle discharge ports or channels: Blow them out with compressed air, or clean and flush with gasoline if compressed air is unavailable. * Incorrectly set diaphragm lever: Reset the diaphragm lever so it is flush with the floor of the diaphragm chamber. * Throttle shutter cocked in the throttle bore: Reset it. * Dirty nozzle check valve or outlet screen: Clean or replace them. * Welch plug covering the idle discharge ports does not seal: Replace the welch plug, following the instructions outlined in service hints.
T
taylormichaelAug 16, 2025
Why does the carburetor flood on my TILLOTSON HU?
- Z
  Zachary ChangAug 16, 2025
  If the carburetor of your TILLOTSON Engine floods, it could be due to a few reasons. It might be caused by dirt or foreign particles preventing the inlet needle from seating properly; in this case, remove, clean, and replace the affected parts. Another cause could be a diaphragm lever spring not seated on the lever dimple; remove the lever and reinstall it correctly. Lastly, the diaphragm might be improperly installed in the carburetor; replace the diaphragm or correct its installation.
G
georgedevinAug 21, 2025
What to do if TILLOTSON HU carburetor runs rich with the high speed mixture screw shut off?
- G
  Gina AlvarezAug 21, 2025
  If the carburetor of your TILLOTSON Engine runs rich even with the high-speed mixture screw shut off, it indicates that the 3/6” diameter nozzle cup plug, or nozzle cage, is not sealing properly. To resolve this, install a new plug or a new cage check valve.