Rotec TBI on a AeroVee

[tom0nex74]

Has anyone had any experience with a Rotec TBI throttle body on the AreoVee 2180? I am having difficulty keeping the Aero-Injector in tune.
Tom Ryan 0nex 74

[Brett]

That's surprising, normally they are set and forget. Are you using the TBI-34-r ?

[lgsievila]

Hi Tom,
Do you have a MK I or MK II? There were some problems with the regulator on the MK II and I did have some problems. I also had problems with the MK I and Rotec replaced the MK I with the MK II. Then the regulator went bad on the MK II and Paul gave me upgrade replacement parts for the MK II when I was in KOSH in 2017 but by then I had given up on the AeroVee and hung a 2200 Camit on my Onex. The Rotec TBI's work great until they don't.

[WaiexN143NM]

Hi all,
I think tom is saying he has the aeroinjector installed and is asking for input on the rotec if he decides to switch. i love the rotec products, after john had his forced landing i didnt fly my waiex for 2 months till i got the new upgraded diaphram design installed. the old design had a diaphram with a floating oring. the new design has the oring molded into the diaphram. i wouldnt fly a mark I or II rotec
with the old diaphram. new diaphram primer/regulator overhaul kit about $100. pick one up at oshkosh, or order one online. last i heard rotec was setting up a distributer in FL.
we installed the rotec 40S on our jab 3300 , adjusted the idle mixture , installed the new diaphram , thats it in 5 yrs.
new sales have the updated diaphram. if in doubt, take the primer regulator apart .

safe flying!

WaiexN143NM
Michael

[Brett]

Soz Tom ,, I miss read.
I had one of the very first few Mk2 fail hence very long story why I did an engine conversion in the end. I had not realised the Mk2 had an upgraded diaphragm kit available. I wish Rotec had bothered to put out an advisory on that issue clearly they knew about. Had I done that I’d prob still be flying around the Aerovee Turbo/Rotec tbi combo.

[Fastcapy]

After continuous issues with an Aerocarb and Aeroinjector I switched to a MKI Rotec. I did have an idle issue develop after about 100 hours on it and it was the O-ring. Replaced that with the upgraded style and have had no issues since.

The Rotec like others have said eliminated a lot of the constant fiddling around I was doing with the Aeroinjector. Even with the idle issue I had with the TBI it was way more reliable than the red ones I originally tried.

[Onex107]

There is no doubt that the Aeroinjector takes some "fiddling" before it works well on your engine. I think some of the reason is, it isn't explained very well in the set up instructions. They give you several needles for a reason. As the needle number goes higher, the taper angle increases. You can calculate it. The higher numbers don't just mean the needle is richer. There are two sweet spots on the needle you are interested in. The thickness at the orifice for WOT and the thickness at the orifice for idle. These two thicknesses need to be within the distance the slide moves so they are in the correct position for both settings. The distance between these two thicknesses gets closer together as the angle increases.
My experiance with the #2 and#2 1/2 was when the needle was set for WOT the idle was too rich and had to be controlled with the mixture. I, and a few others, have ended up with the #3 needle and no longer have to lean radically to prevent the engine from stalling at idle after a flight. I haven't touched the needle adjustment for 250 hours. I control the EGT and CHT with small mixture changes. I don't touch the mixture from one flight to the next, and only then if #1 gets a little hot on climb out. My plugs are clean. I don't have to be concerned about carb ice like I did in the Cessna. It happened to me twice, once at altitude and once on the ground. It can shoot you down. Don't give up on the AeroInjector until you talk to someone that is using it successfully.

[Arjay]

Has anyone had trouble getting a Rotec MK II tbi to run correctly on a 2180 Aerovee? We just got ours installed after a year delay. Installation is standard Sonex, no fuel pump, no gascolator. Fuel line comes straight out of the fuel cut-off valve, thru firewall, through 90 degree elbow, down engine side of firewall, through another 90 elbow, through in-line filter, then straight to tbi inlet.

When we first started it it started up and ran great with no priming. We got 3250 static rpm at wot and smooth idle at 1000 rpm, and smooth running throughout the rpm range. Then we cut it off. Two weeks later we made some adjustments of throttle stops and tried it again. This time it would not start or run without constant priming, like it was not getting enough gas. We could not get over about 2500 rpm, or get it to idle under about 1500. We are pulling out our hair because we can not find anything that changed between when we first started it two weeks ago and now.

I have sought help from Rotec, but they have not responded. The tbi did not come with a service manual and I am reluctant to take it apart without knowing what to look for, how to determine whether there is a problem and how to get it adjusted and RE-assembled correctly.

I NEED HELP. Any experiences or ideas from you guys (and, of course, girls) would be appreciated.

Ron
Legacy Sonex taildragger with aerovee

[WaiexN143NM]

hi all,
First is this a new or used rotec? mark 1 or 2? mark 2 with the built in regulator? upgraded diaphram? easy to take apart the primer assembly.
make sure you put it back correctly. take pic with cell phone as u take apart. pin needle spring diaphram.
make sure the diaphram has the molded in version, not the floating version o ring.
yes rotec should have put out a service bulliten .
provided the upgrade parts for free.
maybe the lawyers advised them not to.
and yes dealing with rotec , calls or emails, sales or service , will make you retreat alone to the wood shed with a beer.


WaiexN143NM
Michael.

[Arjay]

Michael:

Thanks for your input.

The tbi was purchased new a year ago directly from Rotec. It is a Mark 2 with built in regulator. I had no trouble getting answers from Paul at Rotec when he was trying to sell me the tbi last year. Now, when I need help he is totally non responsive.

Ron