Diagnostic Services

Accurate Testing and Troubleshooting for Small Engines, Trucks, and Power Equipment

At National Restorations, LLC, we provide complete diagnostic services for small engines, outdoor power equipment, generators, and light-duty trucks. When something’s not working as it should — but the cause isn’t obvious — our skilled technicians use a combination of computer-assisted tools and hands-on inspection to identify the problem.



Located in Queenstown, Maryland, we serve customers throughout the Eastern Shore region who need accurate, timely answers about equipment failures, poor performance, or sudden shutdowns. Our diagnostic services help prevent unnecessary part replacements and give you confidence in your next repair decision.


Whether your lawn mower is sputtering, your generator won’t hold a load, or your truck is misfiring, we’ll find the issue fast — and explain it in plain language.

What Our Diagnostic Process Includes

Every piece of equipment has different needs, but our diagnostic process follows a clear and effective structure:

Visual Inspection

First, we check for obvious signs like cracked hoses, leaks, worn wiring, and physical damage

Engine Start/Run Tests

We observe how the engine starts, idles, and responds to throttle under load

Compression Testing

This helps us determine the internal health of an engine’s cylinders and seals

Fuel System Testing

Includes fuel pressure, fuel flow, and injector operation (where applicable

Electrical System Checks

Covers spark plug output, ignition coil testing, battery voltage, and grounding

OBD Scanning (for trucks and newer engines)

Pulls error codes for systems that use onboard diagnostics

Load Testing (for generators)

Confirms whether the unit can handle power draw consistently

This process ensures we don’t miss any contributing factors and gives you a clear explanation of what’s wrong — and what’s working fine.

When Do You Need Diagnostic Services?

Not all problems show up as clearly as a broken part. That’s where proper diagnostics come in. You should schedule a diagnostic service when you notice:



  • Equipment that won’t start or is difficult to start
  • Engines that stall under load or lose power
  • Irregular idle, misfiring, or backfiring
  • Strange vibrations, smells, or noise during operation
  • Warning lights on vehicle dashboards
  • Poor fuel efficiency or loss of torque
  • Generators that won’t maintain voltage


Rather than replacing parts blindly or making assumptions, we run detailed checks on every system involved.

Common Equipment We Diagnose

We provide diagnostic services for a wide range of engine-powered equipment, including:



  • Lawn mowers (walk-behind and riding)
  • Weedwackers and leaf blowers
  • Chainsaws and snow blowers
  • Generators
  • Log splitters
  • Tillers
  • Small trucks and light-duty commercial vehicles


Our service applies to both gas-powered and electric-start systems, including two-stroke and four-stroke engines.

Why Choose National Restorations

  • Experienced, skilled technicians who don’t rely solely on computer readouts
  • Clear explanations and no-pressure recommendations
  • Local, independent business with fast turnaround times
  • Support for a wide range of outdoor power equipment and vehicles
  • Transparent quotes and responsive customer service


We don’t believe in vague advice or unnecessary part swaps. We diagnose issues correctly and help you move forward with confidence.

Trusted by Homeowners and Businesses Alike

From residential clients with seasonal tools to professional landscapers and small business fleets, we work with a wide range of customers who need their equipment to run reliably. Our team provides straight answers, realistic timelines, and reports that explain everything we find.



For many customers, our diagnostic service is a valuable step before deciding to repair or replace equipment. Knowing exactly what’s wrong — and how much it will cost to fix — helps you avoid unnecessary spending.

Book a Diagnostic Appointment Today

If your equipment or vehicle isn’t running right, bring it to National Restorations, LLC for professional diagnostic testing. We’ll help you get answers fast and plan the next step forward — whether it’s a repair, adjustment, or seasonal tune-up.