ECHO GT200R 21.2cc Weedeater Conversion
This engine began life as an Echo GT200R Weedeater, then transformed into a nice little R/C airplane engine having a 21.2 cc displacement rated at 1.525 horsepower and weighing in at a mere 40 ounces.
Here it is in its basic form after all the weedeater casting components were removed from the crankcase. It had lots of run-time as a weedeater, thus having lots of carbon to be removed especially from the piston and combustion chamber.
I used a case-cleaner (tumbler) for the cleaning job. As you can see it worked very well.
The ECHO (Kioritz 21.2cc) engine has a high quality crankshaft assembly consisting of a forged double-bell crankshaft and connecting rod. Plus it has PTO capability. Not all Echo (Kioritz) engines are created equal. The 2000 series engine is nice but doesn't have near the technology of the GT200R engine.
The cylinder on the left is the GT200R and has a full diameter sleeve whereas the 2000 (on the right) doesn't. The GT200R cylinder also has a larger exhaust port, larger piston port, and no EZ start compression release. In other words, the GT200R engine is designed for high RPM and high horsepower as compared to the 2000.
The GT200R also has a "true" hemi combustion chamber and the 2000 is merely semi-hemi. This photo also illusrtates the differences in the transfer ports.
I performed some minor modifications to enhance the fuel flow through the crankcase and cylinder. Basically, I scalloped the sleeve and matched the piston to the new opening.
Now that the engine is clean and the mods done, it's time to make an airplane engine out of it.
A few partsd need to be machined, specifically a prop hub and a timing hub for the ignition. All of the original ignition parts were thrown out including the coil and flywheel.
Here is the prop hub fitted on the crankshaft to check it for run-out and overall fit.
The engine nearing completion!
All that's lacking is a carb assembly, muffler, and electronic ignition.
There are some striking similarities between the ECHO engine and the FPE 1.3 engine.
That's because they're one of the same! This good, as there's lots of after-market parts available to "convert" the Echo weedeater! Namely, the prop hub, ignition parts, Pitts muffler, and other minor components.
Here it is, a full blown running conversion!
After some run-time and minor changes, the engine is turning up to 8300 RPM. I have decided to put this engine into a Great Planes Super Skybolt.