Seven 37 Hp Vanguard EFI Problems And Their Fixes

37 HP Vanguard EFI Problems

If you have a vast piece of land or choose mowing as an income-generating venture, you need a mower fitted with a powerful but fuel-economy engine.

The 37-Hp Vanguard EFI could be one of the options you may need to consider. The tractor is equipped with a Vanguard engine with a 37.0 HP engine with immense capabilities.

Vanguard is one of the best commercial engines. It is robust and comes with a 993 cc engine making it one of the fastest mowers in the market.

The tractor features a high-performing engine that is easy to start and guarantees consistent power output.

But just like other mowing equipment, there are a host of 37 Hp Vanguard EFI Problems you will need to learn to fix on your own. It will enable you to enjoy mowing using 37 HP vanguard efi.

Table of 37 HP Vanguard EFI Problems

1. Cranking difficulties– Disconnect the spark plug wires and reconnect them
– If the voltage is less than 12.5V, charge the voltmeter
– Check the wire connections
– Clean the plugs and remove debris
2. Fuel issue– Replace the old filters
– Use high-quality fuel
3. Overheating– Deal with overheating issue as it arises
4. Engine-producing smoke– Use the right lubricant Use the recommended oil
– Change the oil
– Replace worn-out parts 
5. Dirt accumulation– Clean the fins and remove any build-ups
– Clean the screen and remove grass and debris
6. Ignition system– Change the ignition system
7. Loss of power– Use stabilizers when storing fuel
– Use fresh and treated oil
– Spray the fuel tank and the carburettor with carburettor cleaner
– Remove the plastic packing plug to allow for proper venting

1. Cranking Difficulties

For many reasons, the Vanguard engine may not start when you turn the ignition. If the spark plug and the battery are old, it will not start.

Similarly, if the crank position sensor is wrongly positioned, the mower will not crank. The cranking sensor needs to be placed optimally for the engine to crank.

Typically, the optimal position entails setting it between the 15000-20000 readings. The least you can go is 12000, but the engine will not crank if you go lower than that.


  • Disconnect the spark plug wires and reconnect them.
  • Use a voltmeter to check the voltage across the battery. It should be 12.5V. If the voltage is less, consider charging it.
  • Adjust the sensors and position them between 15000 and 20000.
  • Check the wire connections.
  • Clean the plugs and remove debris and any unwanted dirt.

2. Fuel-Related Issues

When the EFI engine starts behaving weirdly, it signals that something is wrong either with the fuel or the fuel filter.

Feeding your mower with low-quality fuel will likely affect how the engine runs. Also, using old filters compromises how the EFI engine works.


  • Replace the old fuel filter
  • Ensure to buy and use high-quality fuel

3. Overheating Problems

Overheating is a common problem in V-twin turbo or Vanguard EFI fuel pump engines. Also, blocked fuel lines will result in overheating.

Similarly, using a low-grade lubricant or having faulty lines and blocked airflow could result in overheating issues. If left unattended, any of these problems may lead to overheating.

Even if it is a minor problem, it must be checked and solved before it deteriorates. If you leave the small problem to go unsolved, it may tear and wear part of the metal.


  • Deal with overheating issue as it arises

4. Engine Producing Blue or White Smoke

If the Vanguard engine has oil or fuel-related problems, it may emit white and blue smoke. These could happen if you use low-quality oil. Similarly, it could happen if you don’t balance the oil levels.

In some cases, tilting the engine excessively could make it release white or bluish smoke.

Furthermore, faulty caskets and overfilled crankcases lead to burning oil and could be responsible for the white smoke.


  • Use the right lubricant.
  • Read the manual and use the recommended grade of oil.
  • If the oil has been sitting in the tank for a longer period and has changed color, ensure to change it.
  • Replace worn-out parts such as the crankcase, head gaskets, and worn-out rings.
  • Replace the rings and worn-out cylinders.
  • Avoid tilting the engine for any reason.

5. Dirt Accumulation

Vanguard engines feature blocks and cylinder head fins that help transfer heat from the engine. So when they are dirty and debris accumulates in the fins, this function is hampered.


  • Use a  brush to clean the fins and remove any build-ups.
  • Carry out general cleaning after 100 hours of use.
  • Clean the screen and remove grass and debris.

6. Ignition System Problem

Maintaining a healthy ignition system is important since it reduces the chances of the mower refusing to start.

To maintain the ignition system, start by pulling out the spark plug. You may do this using a wrench. Also, remember to adjust the gap and install the spark plug.


  • Change the ignition system.

7. Sudden Loss of Power

Sudden loss of power is a common problem in most engines. The problem is linked to maintenance issues, including stale fuel, deteriorated oil, and fouled spark plugs.

You may avoid these issues by carrying out regular maintenance. For instance, you may organize an annual tune-up.

Also, do not allow untreated fuel to sit in the tractor for a month. If it does, ensure to drain and replace it with new oil.


  • Always use stabilizers when storing fuel.
  • Use fresh and treated oil.
  • Make it a habit to spray the fuel tank and the carburettor with carburettor cleaner.
  • Remove the plastic packing plug, which is always placed between the gas tank and the gas cap, to allow for proper venting.

Other Vanguard Problems

HP Vanguard comes in different models and series. Some series share problems, while some feature unique issues.

28 Hp Vanguard EFI Problems

The model suffers from clogging of the injector, which makes the engine run lean. When the engine is clogged, it loses power and could end up failing if the problem is left to persist.

Besides the clogged engine, the mower’s oil pressure can go bad and make it suffer from spark plugs problems. Users have also noted that the engine hesitates and stalls when accelerating.

Fortunately, this is a problem you can fix by ensuring that air filters are clean. Sometimes, you may need to replace the fuel filter and reset the spark plugs.

35 Hp Briggs & Stratton Vanguard Problems

35 Hp Briggs & Stratton Vanguard experiences problems common to most farm equipment engines. For instance, the engine can fail to start or can run poorly.

Besides, the engine is susceptible to fuel line issues, carburettor, and ignition problems. The engine may also experience misses, especially when under a load.

Cleaning the fuel lines and replacing filters can solve most of these problems. Moreover, you can avoid the problems by emphasizing maintenance.

Vanguard EFI Review

Vanguard EFI stands out from the crowd as one of the mowers you can trust for commercial applications. Briggs& Stratton makes use of the efficient Vanguard technology in its construction.

Also, the manufacturer uses the engine control module to tune the operating points and make the engine work efficiently.

Thus, unlike other engines, vanguard is easy to start and performs superbly well in varying temperatures.

Vanguard EFI is simplistic in design and offers adjustable settings. The mower moves at a speed of 10.5 MPH allowing for clean cutting.

Therefore, the engine makes a good option when looking for mowing equipment. When you combine these features with the fact that it offers operators a comfortable ride, it becomes one of the tractors to consider.


Who manufactures 37 Vanguard EFI engines?

Briggs &Stratton Corporation is the outfit that manufactures 37 Vanguard engines. The company was established 113 years ago and is based in Milwaukee, US. Since its inception, the company has delivered hundreds of thousands of work engines.

Is 37 Hp Vanguard and Briggs &Stratton the same?

37 Hp Vanguard is one of Briggs &Stratton’s engines. The company has been operating since 1908 and manufactures high-performance engines designed to power work equipment. The company designs and manufactures engines. It also manufactures Vanguard parts and engines that deliver maximum productivity. Also, Vanguard is committed to improving power performance and reliability.

Are 37 Hp Vanguard EFI mowers good?

Vanguard EFI is a good mower. It has been around for over 113 years and continues to receive praise from current and previous users. But you will need to replace the fuel and air filters often to continue enjoying its service.


Vanguard EFI is one of the best-performing mowers from Briggs & Stratton. The mower features a high-performance Vanguard engine designed to power work-based equipment.

It is a 37-Hp engine with a displacement of 993 cc and features two cylinders. The engine boasts V-Twin OHV technology, giving it a superior balance and low emissions.

Thus, if you are looking for a mower with an improved valve life and better fuel economy, Vanguard EFI is one of the options you may need to consider.

However, despite its many advantages, there are various 37-Hp Vanguard EFI engine problems you may need to learn to solve.