# Recent content by GTX_Engines

1. ### $10 gallon Avgas This paper dated 2018 states that 100LL contains 0.13% Tetra ethyl lead. I think the facts stated are from 2013. MSDS for Phillips 100LL 2. ###$10 gallon Avgas

Simple question: Does lead decrease volatility to the point where leaded fuel will not vapor lock as easily as does recreational pure gasoline? I say no, and have a BS in chemistry. My wife has a PhD in chemistry and she agrees with me. We agree that changing a metallic content in a volatile...
3. ### Crashes in the News - Thread

A good friend died Friday night in Indiana in the hospital after succumbing to burns suffered from a chash while testing one of his latest Brantley helo rebuilds. This is what he did for most of his later life, and it comes as a shock to all of us in the PRA. He was the best Brantley rebuilder...
4. ### The Prop windmilling on RX1/Apex engines

Gyrocopters are in autorotation at all times. Helicopters are not. When a helo engine quits, the helicopter must have at least 45 MPH foward true AS in order to autorotate and glide to a safe landing. This requires a minimum 200' AGL from a hover, zero AS. Since a gyrocopter is ALWAYS in...
5. ### The Prop windmilling on RX1/Apex engines

YOU DO NOT NEED TO HAVE A CLUTCHED PROP ON A YAMAHA RX1 OR APEX. If you are concerned with best glide flight, then don't use a clutch.
6. ### The Prop windmilling on RX1/Apex engines

Mohawk Aero has a variety of gearbox options, as well as clutch and no clutch. They always have, and they always will, since 2012. These are now available to work with RX1, Apex, Phazer, Nytro, Attak, Vector, Rage, Mountain...in other words ALL Yamaha Genesis (YG) engines. In some cases, such...
7. ### Yamaha Aircraft Engines: A History & Buyer's Guide

Take a look at this dyno chart provided by an aftermarket group. I don't believe their reported numbers showing the huge increase in power when their product is installed, but at least this gives us a pretty good idea of what's going on with the power at any given SPRM. For CRPM multiply the...
8. ### The Prop windmilling on RX1/Apex engines

There may be some misconception about Yamaha conversion engines here. ALL YG2 and YG3 engines must have a clutch to start the motor, since it won't rev through to a smooth idle when hard coupled to a prop. It's like trying to start a bike while in gear. Next, there is no need to use a...
9. ### Yamaha Aircraft Engines: A History & Buyer's Guide

Here are two other threads that are suitable for the new "YAMAHA" category: First 160 HP Yamaha EXUP aircraft yamaha-160-hp-stock-170lbs-installed
10. ### Yamaha Aircraft Engines: A History & Buyer's Guide

It is wonderful to see Yamaha Genesis engines have now been provided their own category here on HBA. Thank you. HISTORY Pretty sure this is your first thread on the subject. First mention of Yamaha on Homebuiltairplanes The thread above was posted 10/9/2010. I found the HBA forum and that...
11. ### Engines to replace the dominance of Rotax

It is my understanding the inverted cylinder engines were popularly abandoned nearly 100 years ago for good reason...there's a better way to do it. The only good reason in the first place to do it was to lower the cowling height from the thrust line on tail draggers during ground ops. If that...
12. ### World's First 160HP Stock Yamaha Aircraft Engine is FLYING!

Video of the Yamaha 160 HP EXUP flying at CUB airport in Columbia the other day, sounds great - MUCH quieter the 150 HP IO-320 belonging to my buddy that took off right after the gyro did, although Scott didn't catch it on the vid <sigh>. Additional info on the Youtube post. Enjoy. Mohawk...