Information brochure about converting Geo-Suzuki G series engines for Homebuilt aircraft and other air propeller driven craft.



Description: C:\Users\Vassili\Pictures\Eagle\eagle_geo_new\1'.JPG




This brochure is intended for experimental aircraft (and other air propeller driven craft like airboat, hovers) builders thinking about using 4-stroke auto/moto conversions, or already decided to go this way. For them who doesn’t happy to use a noisy 2-stroker or complicated and expensive aviation 4-stroker. And for them who started to work with GEO-Suzuki G serie engine conversion and looking for possible information about these conversions.  

Right engine choice is very important for each aircraft builder. I had the same problem about 20 years ago when started to build and fly delta wing trikes. I made my choice. I used my aviation engineer education, builder skills and pilot experience to create the engines for my aircraft. I’m sure it was the right choice for me. Dozens of aircraft were designed, built, repowered, engines converted and tested with hundreds of flying hours.

Now I have Air Trikes Enterprises – my business and my hobby the same time. I sell proven, reliable, fuel efficient, easy to build and not expensive 4-stroke experimental aircraft engines + parts necessary to build them. I sell trikes powered with these engines. I tried different engines and have conversion kits for them available, but my favourite engine is GEO-Suzuki G series. Dozens of customers said me thank you for well done work.

This is not a strict guideline what or how to do. I’m not a teacher but the same experimental aircraft builder as you. Maybe better educated and more experienced than some of you. I don’t want to teach but wannt to share my experience with you. I hope it will be useful. But only the builder have right to decide what to do, how to build his EXPERIMENTAL aircraft, what components to use. This is your privilege and your 100% responsibility, don’t forget it.

Best regards,

Vassili Tarakanov
Aerospace Engineer,
Canadian UL Instructor
Air Trikes Enterprises Manager




Why an auto conversion?

Why Geo-Suzuki?

Engine choice.

Engine finding and purchasing. Should you overhaul?

Conversion system parts.

Engine control system.

Choice of engine accessories.

Cooling system.

Fuel supply.

Propeller choice.

Cockpit engine control instruments.


12 pages of text.


SPG 3(4) gearbox 2 pages

Motormount L-bars, motormount frame and spacer drawings 7 pages

Light pulley drawings 5 pages

Flywheel machining drawing 1 page

Alternator brackets 2 pages

Alternator belt strainer drawing 1 page

Coolant expansion tank drawing 1 page

Table to calibrate Stratomaster Engine Monitor for using with G13 Water T sender

Engine control system schematics and tables (G10, G10Turbo, G13BA, G13BB) 6 pages

26 pages of enclosures 38 pages total.



That is briefly all the information that I wanted to share with you, and I hope that it is more than enough to make your choice and start working with your own GEO-Suzuki conversion; or that you now know enough to decide otherwise.

If you have particular questions about GEO conversions, ask me by emailing to and I will answer them, but please be specific in your emails. Wide-ranging general questions like “Hey, say me more what you think about GEO (airplanes, propellers etc.)” are beyond the scope of this offer.

In this paper version of the brochure I have not included photographs because they do not reproduce well enough to give good technical details. If you would like to see pictures then spend some time going through my website where you may view photographs and read the Feedback from builders. Click on the pictures and you will find that most of them have high resolution versions. If you can’t find what you want, then ask me by email. I will answer and send photos to illustrate my answer.

I did not include the specifications of the engines or the overhaul info. This information can be found in Haynes or similar automotive manuals. I have not given basic step-by-step instructions for novices, nor have I given hop-up instructions. These are not very important for the typical builder who wishes to have a simple installation that will fly within a short timespan.

The most important considerations that I would like you to understand are:

The Geo-Suzuki engine with SPG-3 gearbox is not an “alternative” (which many people interpret to mean weird, more complicated or lesser) way for builders who cannot afford to buy “good & proven Rotax 912S". The Geo has its advantages, as does the Rotax 912. My opinion as an aviation engineer and pilot, and the opinion of many builders and pilots who have tried both GEO and 912 engines is that the GEO in many aspects is the preferable choice.

This method of powering your craft does not take a long time to achieve, nor is it complicated. Of course you can make it a long and complicated process, but that is another story. Please do not try to solve problems that do not exist, and do not try to be smarter than the Suzuki engine designers, especially if this is your first engine conversion. Do not try to modify or overhaul the engine if it is not necessary. Many builders begin with the assumption that they must first do a complete rebuild… and they never finish the project, telling others that converting a Geo is a complicated and difficult process.

My advice to the builder who wants to fly more than build is to take the standard engine from the car, buy the necessary conversion components, put your engine together, and test the aircraft to be certain that the engine choice is correct. You can change the block if yours is worn out; they are cheap. Later when you know for sure that it works you can remove several pounds from the engine using light components, install a quiet muffler instead of a noisy straight pipe, make a nice cowling or radiator scoop, modify the engine a little and make your conversion “perfect”. I don’t know many planes which are prevented from flying because their engines are 10-15 pounds too heavy, or not nicely painted, or have some oil leak through an old seals, or have some other minor concern, but I do know a lot of never- finished projects that were started by perfectionists.

As a last word, I ask you not to copy any part of this brochure or the enclosures.

I will be waiting for your feedback and suggestions for changes or corrections to this brochure. Fly safely!

Vassili Tarakanov