YG3 Achilles Heal News

NoWingsAttached

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Over the past couple of years my good friends at Tango Gyro have discovered an Achilles "heal" with the Yamaha Genesis 3-cylinder (YG3) engines they use exclusively: The water pump impeller is plastic. It breaks and spins off the shaft, causing the engine to overheat. In most cases this results in a blown head gasket at the very least, and worse. In each case I am aware of the pilot was able to land under power.

In at least one case there have been multiple impeller failures on a single engine.

Last week I did some research and discovered that this has been happening to sledders running YG3's since the introduction of the YG3 series in 2006, on sled models including Viper, Nytro, and Vector, and newer Sidewinder and Wild Cats (Artic Cat). It has been happening on brand new sleds, sleds with low miles, sleds with medium miles, sleds with lots of miles.

It is indiscriminate, and you need to:

CHANGE YOUR WATER PUMP IMPELLER if you are flying ANY Todd Reick YG3 aircraft, or ANY Tango Gyro.

Please contact [email protected] for replacement parts made from billet aluminum and hardened steel shaft.

Cost is $249.95 + S&H.

NOTE: THIS DOES NOT AFFECT YG2 OR YG4 ENGINES. All of the YG4 and YG2 engines (RX1, Apex, Phazer, etc.) have been built with a metal impeller, not a plastic one. MAC has not sold any YG3 engines or kits, so this notice does not affect any MAC customers.
 
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Sv.grainne

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Kerrville, Texas
I helped in the rebuild of 2.5 of these water pumps and installed metal impeller in one. If you do this yourself make sure you properly install the front seal (seal next to the impeller). There are 2 parts to this seal, one for water and the other for oil, but they both have to be installedand when properly installed the ceramic faces on the seals will touch each other.

Have seen 2 now where only 1/2 of the seal was replaced!

pump.png
 
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Resasi

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Heel, not heal. (The vulnerable spot on Achilles’s body where he could be injured. This due to the fact that when his mother Thetis dipped him in the river Styx in order to make him invulnerable, she was holding by the heel which then wasn't covered by the water, thus leaving that one weak spot. He was then killed by an arrow shot by Paris that hit him in the heel at the siege of Troy.)

Sounds like a good spot on a weak point in the engine. Well done.
 
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NoWingsAttached

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Joined
May 21, 2006
Messages
4,897
Location
Columbia, SC
Aircraft
Air Command Tandem w/ Arrow 100hp; GyroBee w/ Hirth 65hp; Air Command Tandem w/ Yamaha 150hp
Total Flight Time
>350
Amusing, since HEAL is a homophone pun: it can be fixed, unlike in Achilles' case where it was the end of an illustrious career.
 
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