SonexBuilders.net

Hello,

I got the MKII coming on the way, been getting ready to install it on a Jabiru 3300A replacing Bing 64, my understanding its direct replacement but some head scratching needs to be done for the throttle/prime/mixture cabling/routing.

Anyone installed Rotec MKII TBI on a Jab 3300? Any info and photos would help a lot.

Regarding the Prime on the Rotec TBI, i read somewhere someone used a solenoid to press the prime rather than cable and associated design, any tips or pointers on that subject will be great.

Cheers
NAR

Sounds like a good idea re the elec solenoid idea. I have a mark 1 on my aerovee and installed a cable however. The only thing I guess to consider is the fact that if you do have an issue, and the regulator fails, it will probably fail with no fuel flowing and the primer is there also to get you home by over riding it as a fail safe. If an electric solenoid was used I suggest you get one that can stay energised for a long period not just a short on off type. I have often thought I need to change my cable to one that will stay out like a mixture cable. The one I have is just a normal pull cable with no hold feature. The thought of having to hold the cable out for the whole trip home if there was a problem leaves me a little nervous. Probably unlikely but I guess could happen. Just thinking about this now as I type, I wonder if the diaphragm has a life span or change out period in hours or years as part of a service schedule.

Thank you Brett. Can't you use the Choke type pull where you can rotate it to lock (pulled) in place without strain when you need to? Like this one http://1drv.ms/1Jeta5L

Post some photos of your cable setup for the primer if you don't mind. If i can't find a solenoid, going to have to use the cable!

I possibly could use that type of cable. Worth a look into :)
Next time I have the cowls off the plane, I will take a photo and post it up , no worries.

I am wondering if there has ever been a case where the regulator on a Rotec TBI failed and someone had to keep the primer depressed to keep the engine going? Will the engine run OK with the primer depressed for an extended period? In the Rotec literature they mention pressing the primer button a few times to clear out vapor lock if it were to occur. From what I understand, when you press the primer button it really let's the fuel pour out. Can the engine run with that much fuel being released? I just fabricated my primer lever and A920 throttle cable attachment for my Rotec MkII TBI and am trying to decide on a cable setup for the primer. I am also going to put a spring on the primer level to pull the lever off the primer button when not purposely depressed.

Jake

Hi jake,
First just want to say that we are extremely pleased with our rotec tbi mk 1 on our jab 3300 . Just a reminder when u prime make sure throttle is opened up full to expose the spray bar with all the holes, otherwise priming does nothing. Install instructions from rotec require a carb heat install, although many have done without like the aerocarb/aero injector. Can u get carb ice in a throttle body? That is a whole nother thread and discussion. We ordered the carb heat box and flow grid from aircraft spruce for the Ellison throttle body. The heat box was way too big to fit between the motor mount tubes so we made a smaller version of it and sent back to spruce. We did incorporate the flow grid piece, about $100 . Never tried without it , but hope it's doing its job. Heat muffs that work and are small in size to fit the jab3300 exhaust you can get from wicks or spruce is the 'cessna' style. I believe u have the aerovee so u have more room on the exhaust pipes for bigger muffs. We have 2 , one for carb heat, one for cabin heat. We have never tried pulling the primer when in flight, need to try that , see how it affects the engine. Again the more open the throttle is the more of the spray bar is exposed, when priming.
Thanks for the input on the fuel tank fittings. It's been a hot topic. One of the good topics amongst the builders/pilots on the flight line at Rio Linda fly in. When following the instruction via the sonex oops fittings , and after the drilling is done, how much plastic build up inside is still left? Any body else please feel free to chime in with thoughts, experiences, suggestions for the tank fittings
Cheers!!
WaiexN143NM
Michael Radtke

Hi Mike,

It was good to see you at Rio Linda.

Regarding the amount of plastic that surrounds the fittings and remains after the drilling, in my case it was substantial. All of it had to be removed so that the o-rings had a flat surface to form a seal.

If you want to get an idea of how much plastic surrounds the tank fittings, remove your fuel cap and reach in with your fingers and feel around the backside of the fuel vent fitting. The fittings extend beyond the thickness of the tank wall and a considerable amount of plastic forms around the fitting.

The Sonex instructions call this a "ridge" but it is more like a little mountain of plastic. It all has to be removed to provide a smooth surface for the o-rings. I found this to be one of the more challenging aspects of installing the "oops" fittings.

I have a MKII Rotec TBI on my AeroVee. If anyone wants to see my mechanical primer, send me an email and I will send pics.
Loren
nwyooper@yahoo.com

Anyone have any photos of their Rotec TBI control cable setups?

I received a new MKII in the mail yesterday.. and it appears as if one must use a heavy duty push-pull cable similar to these:

https://www.aircraftspruce.com/catalog/ ... ckkey=8714

for the throttle control. Was curious what other people have ended up using

Thanks!

142YX wrote:Anyone have any photos of their Rotec TBI control cable setups?

I received a new MKII in the mail yesterday.. and it appears as if one must use a heavy duty push-pull cable similar to these:

https://www.aircraftspruce.com/catalog/ ... ckkey=8714

for the throttle control. Was curious what other people have ended up using

Thanks!

I think I'm getting mine next week too. I was thinking the same thing and attaching it to the top hole on the AeroConversions throttle quadrant.
Also thinking of using a longer coupling hose to move the carb away from the engine hoping for better atomization. My #6 always runs leaner. Any thoughts on that? Maybe a 45 or 90 degree bend using a silicon hose like this...
http://www.summitracing.com/parts/vpe-2740b/overview/