Getting more power out of your Zenoah G26


Displacement: 1.55 cu in (25.40 cc)
Bore: 1.41 in (34.0 mm)
Stroke: 1.10 in (28.0 mm)
Cylinders: Single, chrome plated
Total Weight: 59 oz
Engine (Only) Weight: 53 oz
Muffler Weight: 6 oz
Crankshaft Threads: M8 x 1.25
Benchmark Prop: 16x8 APC @ 8900
Prop Range: 16x8
RPM Range: 1,800 - 12,000
Fuel: Gas/Oil Mix
Mounting Dimensions: 180 x 193 x 181 mm
Muffler Type: Can
Cylinder Type: Ring
Carb Type: Walbro WT-645
Crank Type: Ball Bearing

G26.jpg (18193 bytes)

The Zenoah G26 is already a potent little gasser, but it has a lot more un-tapped horsepower readily available. Here is how to tap into it:

The factory muffler has too much back-pressure. Either replace it with a Pitts style muffler or replace the existing exit stingers with bigger ones. This will get you a few 100 more RPM's.

Another up-grade is to get rid of the factory supplied carb. The WT-645 carb is very short on performance, only having a 12.7mm venturi and it doesn't have a checkvalve highend nozzle. Replace it with a WT-540. The WT-540 has a 13.49mm venturi, a checkvalve highend nozzle, and it has an ACCELLERATOR PUMP! This carb will greatly improve your G26 performance. Not only will it be easier to start, it will also have a smoother throttle transition and a lot higher higher top-end. These two changes with get you a good 500 RPM increase in performance, raising your horsepower from 2.64 to 3.11 HORSEPOWER! That's a major horsepower increase (about 15%).

BUT we are not done yet! Zenoah times their ignition very conservatively between 24 and 26 degrees. This modest timing is robbing your engine of its full potential. To correct this problem, I installed a retro-fit electronic ignition. These ignition kits are available from CH Ignition. It's a simple bolt-on up-grade and will allow you to time the ignition to a hotter 28 or 30 degrees advanced. Not only will this pump up the horsepower, it will also lower your engine weight by a good half pound or more. With the three upgrades I have just explained here, you will see a 900 to 1000 RPM increase in your engine (about 25%). You will also have an easier starting engine as well as lighter weight.

My G26 cranks out a whopping  3.76 horsepower with 19.68 pounds of static thrust using the Zenoah benchmark prop. That is some serious go-power for a small gasser!        

Greater Southwest Areo Modelers