SonexBuilders.net

hi all,
just a few comments.

thanks for all the discussion on this thread. hopefully better safety within the fleet will be the ultimate outcome.
first, our aeroinjector. i believe the problem with ours deals with mfgr tolerances , especially when machining the main body for the slide to ride in. we didnt try graphite , but i dont think that would have helped. when our jab3300 was not running, the throttle moved very smooth and freely. with the engine running the throttle was locked up, the induction suction caused the slide to not be able to move. a few thousands difference in machineing? we did contact tech support, got the new upgraded heavier throttle cable, made sure orientation of cable and tbi was correct. still the same. we wanted to get flying. oshkosh came so we picked up a rotec 40-S for the jab3300. a heavy throttle cable from spruce, and viola, instantly worked good. 5 min to set the idle mixtue . has worked well for us. no burps. we always run 100LL. we did upgrade to the new diaphram design, after hearing of johns incident, and a couple others on the vans site.
to anyone that i reccomended it to, im sorry you had trouble or lost confidence. i also believe that rotec should be handing, sending these kits out for free.its actually a whole tbi overhaul seal kit.
price on their website $175+ shipping. $90. i did question rotec on the high price of the kit and shipping. paul agreed to ship it to me for $210 total. ok so i got a email back with a pay pal link.
when i did pay i sent a follow up email lettin them know i paid the link and the address to ship it to in tucson. the circus then began. i did not want to fly the plane until the new diaphram design was installed. after a month of waiting i started emailing trying to check on the order. paul sent me a couple of emails stating that a couple of his assistants would take care of me. ugh huh. well constant emails, confusion, more nonsense. finally i sent another email to paul. either refund the money or send the damn diaphram! he assured me a couple assistants would take care of me. ugh huh. finally 2 months after i origionally paid via pay pal, a box arrived. wow, this box is big and heavy. ! upon opening , it contained a rotec jab 3300 alternator upgrade kit. ugh huh. another email asking whats this? oh sorry we sent you another customers merchandise. ugh huh. ok whats his address i ask. ok im sending it usps insured to him . and wheres my diaphram.? oh its in transit to him . can u please give him my address?
i really want to get this diaphram. 2 weeks later i finally received it. 2 1/2 months after ordering it.
and whole lot of my effort to get it. rotec still owes me $25. the package that it comes in had a aust. postage mark with cost of 26 aus dollars , about us $19.20. they wanted to charge us $90 for shipping.
im happy i upgraded the diaphram. im fully confident in the rotec tbi. if you have one i advise on upgrading the diaphram . pick one up at oshkosh if you are attending. save on shipping, maybe barter with paul. the rotec outdoor booth usually outdoors north of the sonex display end of the row.
the aeroinjector. we have one for sale. for a jab 3300 hardly used. make an offer. good luck.
it has some design defects that need to be addressed. the carrier, so it cannot shift and go full lean, the set screw design. the quality control at the vendor who makes it for checking mfgr tolerances, especially the body where the slide rides in. i wonder if the osh and fdl factory crashes if the aeroinjectors were thourghly inspected for the carrier and set screw problem. if not they need to be.
also taking a hammer to something as a tbi is not a way to fix the problem . as keith mentioned from vibration the stainless scew will just work lose again over time. im sorry but i cannot reccomend an aeroinjector with its current design. to the factory, do something. get with the vendor and come up with a redesign of a few of the failure points. maybe an upgrade kit or service bulliten to the ones in the field. listen to your customers. this is a SAFETY issue.
and want to give kudos to sonex , over the years , the customer service from the gals up front. always pleasant and cheerful. any problem with an order, a quick fix on their effort for a wrong part shipped, or wrong address , was quicky addressed and corrected. surely didnt take 2 1/2 months!

WaiexN143NM
Michael

kmacht wrote:Just a point of clarification on the carb comparison. None of the ones listed require a fuel pump. They will all work with a gravity feed system. Some like the rotec and zenith can work with a fuel pump if you dont have a gravity feed system like the sonex does and some like the aerocarb and the revflow wont work with a fuel pump at all. For a typical sonex setup any of the carbs listed will work.

Keith
#554

Keith,
The Bing does require a fuel pump 0.7 PSI Minimum for full flow on a 3300.

David A.

Sorry. I was thinking about the carb options for the aerovee and didn’t look at the bing. One thing to note on the rotec is that it is susceptible to vapor bubbles in the fuel line similar to the aerocarb. The difference is that they do talk about it in their carb manual and have a number of approved solutions (imagine that). One of those solutions is to use a fuel pump with a restricted return line to the tank. If the fuel is constantly moving through the fuel line fast enough it can’t warm up enough to generate the vapor. The return line also acts like the burp tube others have recommended for the Aerocarb carb in the rare case that the vapor bubbles did form. The regulator on the rotec allows a fuel pump unlike the aerocarb Both have trade offs and neither product is perfect. I will admit that.

Keith
#554

When my regulator shut off fuel, even pushing the primer button didn't help.

fastj22

So just curious again about the Rotec, with your install when it failed did you have a fuel pump in the lines or was it solely a gravity fed system?

Brett wrote:

When my regulator shut off fuel, even pushing the primer button didn't help.

fastj22

So just curious again about the Rotec, with your install when it failed did you have a fuel pump in the lines or was it solely a gravity fed system?

Gravity fed. I had 60 wonderful hours of wonderfully atomized fuel to all cylinders. It worked great! Until it didn't.

WaiexN143NM wrote:hi all,
just a few comments.

WaiexN143NM
Michael

Michael,
I understand your frustration with Rotec support. Imagine mine. I have an off field landing due to fuel starvation. Within hours I'm emailing them for help. ZERO, NOTHING, NADA! I investigate myself, find nothing abnormal with the system, no grit, gunk, spooge in the system. Reassemble and it works fine. Not flying it without an answer. I go back to the Aeroinjector. A month later I get a response from Rotec saying the rebuild kit would cost me several hundred bucks. Not gonna do it. I was born at night but not last night. This story is repeated over and over again, not just with Rotec. Think Viking.

End of story, I went back to the Aeroinjector. It works, not great, but its so stupid simple, I have faith it will work. I trust it, I will come to OSH with it.

I have just snuck on 80 hours now with the Rotec.

hi all, john,
i can only imagine your fustration john. an off field landing and busted up wheel pants. it could have been much worse. i have a$400 paper weight. yours is double. . i plan to have a talk with paul this year at osh 18. 1) collect my $25, 2) poor customer service.
im hoping with mark schaible running the show now with some more free reign, he will pay attention, and listen to the customers complaints and take approiate action. such as the aeroinjector. a few design changes could greatly help . a roll pin or rivet so the carrier cant shift. the stainless screw in a metal insert. better quality control for demensions internal . this is small stuff, but would greatly inhance the product. maybe a SB and upgrade kit. some day i may take mine out of the box and see if i cant mill or sand the slide body down a little for more clearance.
some people have had ok luck with their aeroinjector.
im happy where im at with my rotec.
your problem in your rotec diaphram was in the pin and o ring position. it probably shifted correctly when u took it apart. u assembled it correctly and it worked. the newer diaphram has a molded in o ring and better pin design. yes $200. but i wanted to be safe , after your incident, and a few reports on the vans. site.
thanks for letting us know.
see u at osh 18 . have a safe flight.
added: my father spent 38 yrs w mercury outboards in fdl. in carbureation & fuel injection. so please dont any one pipe up and question our ability. thank you.
WaiexN143NM
michael

I have the Sonex aeroinjector in my Onex and have a dual fuel system set up. One is a straight gravity feed and the other has a separate small header tank which drains to an electric pump then a 1-2 lb regulator. When I swap to the pump system I just need to lean a fraction to get equal performance to the gravity system. With the pump system I have steady performance pulling 5g, never have an engine out spinning, no hiccups doing hammerheads and steady engine performance inverted.

What size O ring are guys using between the needle carrier and the screw? also what material type? Butyl? nitrile? viton?