Start here — before replacing any parts
If the engine bogs as throttle rises, verify engine identity and external fuel/air restrictions before investigating internal compression.
Check the installed engine nameplate. RATO R740D service procedures must not be applied to a Briggs-equipped LRT23.
Manual scope: Do not assume exact engine type from sales name
Do these checks in order
Follow the steps below and keep a record of what changes after each one. Stop when an actual cause is confirmed.
Confirm RATO or Briggs from the engine ID plate; never infer this from the AGT model name.
For a verified RATO R740 family, note if the engine hesitates only when applying throttle or also loses power while the hydraulics work. Park safely and let it cool.
Inspect approved serviceable air filter condition, sufficient fresh correct fuel, accessible fuel-line bends and tank-cap vent for obstruction.
If external checks pass, a qualified mechanic should diagnose carburetor passages/fuel pump delivery, valve lash and cylinder compression using the correct engine service standards.
If the problem is gone
Power returns after a verified blocked filter/vent or fuel restriction is corrected: log and recheck operation.
If the problem is still there
Symptom persists under rising throttle or only under hydraulic load: separate internal engine underpower from hydraulic overload with qualified diagnostics.
Which cause matches your result?
Use these more specific checks only when the earlier steps point to that possibility.
01The fuel path is restricted
Have the RATO engine's supply line, vent and carburetor passages checked for blockage or air entry.
Correct the diagnosed blockage or fuel-delivery issue.
02The air filter is clogged
With the engine off and cool, inspect the air filter element.
Clean or replace the approved filter as the engine instructions specify.
03Internal deposits or valve settings are outside specification
A mechanic can test compression and evaluate valve clearance.
Use the RATO service specifications for cleaning, adjustment or repairs; do not guess clearances.
How can I tell it is actually fixed?
Test controlled low-then-moderate throttle at idle and under a permitted light load, with proper safety clearance.
Before buying a replacement part
RATO carburetor and Briggs fuel-injection/carburetor variants require different procedures.
Where this guidance comes from
Primary reference: View the manufacturer or manual reference ↗
Applicability: Do not assume exact engine type from sales name. Source evidence: Real LRT23 owner case; RATO service manual applicability conditional.
The instructions are original English troubleshooting explanations derived from the listed technical facts; they are not a verbatim service manual. Do not apply them to an unverified revision.