I have owned my AMD factory built 601XLB for almost three years. I replaced my tired bungee at that point in time. As you all know it's a pain to do once an engine Is installed.
Well, 200 flights later I see signs that the bungee is starting to deteriorate.
Viking came up with a permanent replacement so I installed it.
Seems well engineered. The install looked easier than replacing the bungee.
Unfortinately it seems that the factory built AMD does not have the plastic cap on the top of the strut. It's welded streel, about 1/8 thick. Took about a half a day with a hole saw before I was able to get the cap off. A couple of other glitches were that the plastic spring liner needs to be trimmed to get the spring in, it won't fit if there is any overlap on the plastic. Also the holes in the straps needed to be opened up a bit to fit over the cross tube. I found that out the hard way, after the he straps were in place.
I am not complaining about these issues, I just want other members of the group of the group to have the info to make a the install easier.
My only complaint, Jan, if you are reading this is paint or powder coat the spring, seems awful cheap not to do so for the price, after all the straps are painted, why not the spring as well?
Also I think a sheet or two of our instructions would be helpful, not everyone has the internet, or wants to be on the computer in the hangar. What would I that be?
Another .25 cents for two sheets of paper?
Thank you Jan at Viking for engineering this product for us Zenith owners.
David Krakowsky

Views: 576

Reply to This

Replies to This Discussion

I have a 2008 AMD 650 LS which needs a bungee replacement now. I'm glad you mentioned this problem with AMD built Zodiacs. I have another question. I need to replace my Bungie right now and my mechanic asked me to find out if it is legal to do the Viking modification on a factory built aircraft which has not been turned into an experimental?

I'm not interested in being a repairman or taking my airplane experimental.
Sorry Robert,
You cannot legally do any modification to a SLSA without factory approval. AMD is out of business, so that's impossible.
Zenith even recommends switching over to ELSA. I don't think a ADS B install is legal without factory approval.
I sent you a message about your bungee, you need a 1080HD bungee. The one you bought should not be used.

Dave, you are correct; an SLSA cannot be modified without written approval from the manufacturer. Also, replacing the rubber bungee on an AMD 601XL or 650LS SLSA with anything other than a 1080HD would be illegal, and if - heaven forbid - there were an accident or incident and an investigation revealed the airplane had a bungee installed other than a 1080HD, whomever replaced it last would probably have some serious explaining to do. It's just not worth the risk.

After studying my options, the only thing that made any sense to me was changing the certification to experimental, taking the 16 hour LSA Repairman - Inspection course, and getting the FAA repairman - inspection certificate.

I'll be the first to admit this may not be the answer for everyone.

Hi Stan
I am also ELSA and have the repairman certificate.
I was asking you if you did the install yourself and how high is your center rod above the aluminum top piece.

Dave, I responded in the thread where you asked about that. We've got too many threads going on the same subject.  :-)

Got it Stan,
What's your cruising speed and max speed? What prop are you using?

I love the solution as well but found the instructions lacking and the center threaded rod that is used to adjust the spring tension appears to wear easily (threaded portion) and was slightly undersized for nut being used. Another builder had the same issue and added a second nut just in case/for safety.

On the later issue with threaded rod, when these concerns were expressed via email to Jan, he replies saying (paraphrased  and  in my opinion only), 'I am not playing these games'. 

That told me all I needed to know. While I love the solution and hats off to Jan for coming up with it....it is doubtful I will purchase anything from him in the future.

Here is a link to the pics for my install... I powder coated the main parts and also had to drill out the top cap..



Thanks for the info Don
Great pictures.

Jan must have heeded your advice.  I purchased and installed the steel bungee and it came with a powder coated spring.  My only glitch was that the arms were too short.  Viking met me at Sun n Fun and gave me new ones and had no problems installing.  Because they showed me great customer service , I purchased the Viking 130 to be installed next month.


New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, power distribution panel, Approach Fast Stack harnesses, Dynon and Garmin avionics, and more.

Custom Upholstery Kits for your Zenith Aircraft:

Zenith Vinyl Upholstery Kits

Zenith Apparel from EAA:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance:


Transition training:

Golden Eagle Aviation

Pianosa Flying Farm

Aircraft Spruce & Specialty for all your building and pilot supplies!

© 2020   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service