Hello Folks. 

My 13-year-old and I are looking forward to eventually choosing a Zenith kit but I believe we are close to picking a powerplant.  I'm considering purchasing an AM15 for most likely a Cruzer, either going with the 117 hp or the 131 hp low profile option. I'm still trying to decide if 14 horsepower is worth $4k.

My son will be using this aircraft to obtain his PPL so simplicity and reliability are a must!

Comparing to the competition, here are my initial thoughts: 

I can appreciate the lack of plastic parts and tubing with the Suzuki/AeroM.  Engine plastics are fine for an economy car, mostly cruising at low engine loads of 1100-2250 RPMs, but probably not a good fit for high-RPM, high-engine load applications. 

I don't doubt the engineering of one of the most reliable automakers in the world, but I'm not 100% sold that same engineering can be directly applied to an aircraft engine. 

I have personally stripped down engines to access and clean intake valves due to carbon buildup that happens from direct injection, I would like to avoid D.I. if possible.  D.I. is also complicated to run properly and can be unforgiving if sensors or tuning are bad.  I've also run into issues with catch cans and pcv/emission systems creating tuning issues as well.  Fuel systems must be spot-on for the high pressure systems also associated with D.I.  It would be nice to not have to mess with the complexity associated with a header tank and additional fuel lines. 

The new AeroM carbon fiber cowling looks pretty cool and lightweight as well, it seems like it can be made to look pretty sharp.


Most importantly, Mark Ketteing has also been very responsive with excellent communication and follow up.  His replies are honest even when they don't fit his invested solutions. 

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I'm excited to see the progression of Aeromomentum's engines, and the nearing completion of several AM equipped aircraft. I think they have a ton of potential, and appear well engineered.

The Viking seems to be a good engine, has lots of hours, and lots of airplanes equipped. However, their engineering feels suspect, and I don't feel confident in their product, my personal opinion. They also can be very aggressive in their marketing, especially when debating different engines, many times disparaging the other engines, with dubious claims. Again, the engines may be fine, but Viking's owner's behavior caused me to lose my respect for the company.

Kudos to Mr. Kettering for bringing an alternative engine to market that has much to offer.   If you believe the Suzuki is your choice, then please just stay on topic.   Better to say what you like about the engine and how the engine suits your mission.   

But many of your comments seem really to be indirect criticisms pointing at a competing product.

Viking has provided around 1,000 engines to the E-AB community over a decade of hard work.   

Viking should not be faulted for attempting to offer clarification here.   But no one can write a perfect response when the objective seems to be to find fault.   1,000 engines says it all.

AND...That speaks volumes for the hundreds of knowledgeable owner/builders that are certainly equally capable of sorting out engine options.   

While I wait out my buy versus build decision, I have personally interacted with several Zenith builders who are now owner/operators of the Viking engine.   Results tell the fact.

All your points about plastic parts and salvaged engines and cooling and direct injection have been seen a dozen times.     

But then you offer us a long list of maintenance issues for Honda engines without any details to put that information into real world context.   Wards Autoworld Magazine lists Honda in the top ten best engines for 2019.    


Here are some photos of recently acquired Honda Engines that customers can see in advance.


I wish Aeromomentum all success.   Alternatives are good for everyone.  

"1,000s of engines" is another example of overstated advertising that rubs me the wrong way. I'm sure there are dozens of happy customers with FAA-certified flying aircraft, there's no need to over-inflate the sales numbers.
My point around engine issues is that Viking should not be advertising their engine as reliable as the original application. All car engines have issues, Honda's engines do as well. Technical service bulletins are simply the manufactures memos towards repairs as made available for a dealer network. Honda TSBs are available to review online. It's very important that everyone understands that Honda did not engineer their auto engines to be used in aircraft, claims should not be made otherwise. Honda didn't manufacture a magical fool-proof engine for Zenith aircraft.

Nobody has made a fool-proof engine, all everyone can do is offer the best they possibly can.

Brady, our sales number are not inflated and now you are simply just making things up, and I have personal dealt with almost every single one of those customers, no need to make false claims. I can in fact produce invoices, address and contact information and I'm still working on adding them all onto our map with pictures of their aircraft! We are not a newer company, and that has allowed us to expand and our sales have been increasing every year in which we are thankful for and owe to a great product and customers that build great aircraft.  

Yes, alternatives are good for everyone, and that's why I continuously call out Jan and Alissa for disparaging and trash-talking other engine providers. Market your engine honestly, and praise it's advantages, don't claim the other guys engine may not have enough power to get over the trees(Jan actually said that about a UL engine).

Ian, I think things can easily sound awful in any "text" form. I do think it is VERY important for every single builder to know what type of capabilities their aircraft is going to have for their own safety margin. 

If you have a 600 ft grass strip, their are things that are going to work better than others, and their are also others than are going to work better for payload and have their own set of pro's (like weight) which we all know the UL is light, and we all know the Viking creates thrust - different builders may need different things depending on various topics. Both have a proven product. 

There have been things said from ALL engine providers that have been down right ugly, the engine discussion can always be a hot topic. I think the only thing that can actually be done is to move forward in a better light. 

I think it can be hard to pull back and say the right "marketing" mumbo jumbo, especially when it comes from a place of passion, and sometimes down right aggravation. 

Jan has said things he shouldn't of

UL has said things that they shouldn't of

Others have as well. 

I think we should all just sit back and listen to some history from WW and he will tell you how long these fellas have been building bridges together and deep down they are like a bunch of bratty brothers, who really mean no harm. This business is not an easy one to stay in, especially when you devote your every minute to it, so the guys like Jan, Robert, Wynn - these guys know their stuff, it works, it has proven itself, and it is here to stay and they all drive me bonkers  :)

Reply by Brady Butterfield  :  "1,000s of engines" is another example of overstated advertising ..."

Just wow.    Never said "1,000s of engines".     You make a clearly false and misleading misrepresentation of what was written.   

Read above and note:  "...around 1,000 engines "  and "1,000 engines".    

Don't see why you need to do like this.    Your intention is obvious.   Not helpful to the community.   

ALSO...As Alissa is rightly saying, there are many different successful auto conversions -- so your comments about purpose engineering are just not valid and a lot of owner/builders flying those engines would tell you so.   Check out all the Yamaha conversions now flying.  


The Engine Forums were created with the intent that builders and flyers of Zenith aircraft could get more specific information about the various engines available.  We specifically invited the various engine vendors to participate in their respective Engine Forum and they could not only provide specific information, but allow promotional information, also.  However, this was done with the understanding they were not to jump in and "hijack" other forums - the only exception being that they could answer specific questions brought up in other forums, such as "how much does xxx engine weigh?", "how many hp does xxx engine make?", etc., but nothing more than that!  In an engine forum, however, the vendor pretty much has free reign to say whatever they want and the members are reminded to consider the source of the information when interpreting the information and particularly when making purchase decisions, etc.

This present thread has degenerated mostly into a non-productive debate.  For that reason, I am closing this discussion to further comments.  The original poster of this discussion can feel free to start a new discussion if he wishes. Further interruption of a discussion by a competitive vendor, however, will not be tolerated.  I would kindly suggest that each vendor let their engine and their customers speak for themselves. Sebastien has advised me that if I come across posts or responses of a commercial nature (outside of that vendor's engine forum), that I may delete them without warning, comment, or explanation.

Thanks for everyone participating and your future cooperation!


Zenith.aero Forum Moderator


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