18KW liquid cooled flex plate problems

Generac, Guardian, Honeywell, Siemens, Centurion, Watchdog, Bryant, Olympian & Carrier Liquid Cooled Home Standby & Commercial generator troubleshooting and repair questions
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actucker
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Sun Dec 01, 2019 5:52 pm

10 year old Guardian Quiet Source 18KW with 1.6 liquid cooled 4 cyl. engine flex plate is breaking regularly. Last flex plate only lasted 3 years with no usage other than the weekly tests. If anyone has any experience with flex plates breaking regularly please advise. Thanks
Chris
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Mon Dec 02, 2019 3:54 pm

This most commonly comes from abnormal vibration in either the alternator end (rotor), flywheel, or the engine itself. The vibration could be a balance issue or a poor running condition like a dead cylinder for whatever reason, or poor fuel or something.
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actucker
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Mon Dec 02, 2019 5:03 pm

Thanks for the info. The 1.6 4 cyl eng seems to run smoothly with no noticeable vibration and it runs at just 1800rpm. Since the flex plats are appx. 1/16 thick, Can "two" flex plates sandwiched together be used?
Birken Vogt
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Mon Dec 02, 2019 5:35 pm

When weird problems like this with no obvious solution start to crop up, sometimes better just to cut and run...just saying....
Chris
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Mon Dec 02, 2019 6:22 pm

I don't think I would use 2 plates. Reason being, it will 'push' on the rotor since you're now doubling the distance between the engine and alternator. The bearing on the other end supporting the rotor may not survive...
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actucker
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Tue Dec 03, 2019 3:28 pm

Thanks to those that replied to my post. I just got through talking to the service manager for Auxiliary Power Systems (Generac Dealer) in Remlap, Al. and was informed that all of the "AIR COOLED" Generac Generators DO NOT use a flex plate between the engine and the stator. The air cooled generators are all direct drive. The "Flex Plate" is a poor design, a weak link and prone to failure in the liquid cooled Generac that I purchased.
Chris
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Tue Dec 03, 2019 5:10 pm

ALL Generac liquid cooled models (and also other brands) use a flex plate between the engine and alternator because you need a flywheel on a liquid cooled engine, which is built into the Air Cooled model engines. The Air Cooled engines are purpose built for the generators and use a tapered shaft to connect the rotor to the crankshaft. Liquid cooled engines (automotive engines) don't work that way...

I have had almost no issues with failing flex plates, and they've been in use for years... They're comparing apples and oranges when talking about the Air Cooled vs. Liquid Cooled. The Liquid Cooled lineup, especially the 1800 RPM products like you have, are awesome generators.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
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