IBob

Someone has been trying to sell a couple of these here for a while. NZ$50 or 60K each, with very much to be done......

They're not shouldered...and it's a sh*t of a job. I cleaned the old sealant out of the thread in the head using a shotgun cleaning brush and acetone (I think that's right?) And initially I misread the manual and used the wrong sealant......so I did it twice. I don't know why Rotax don't do the same as the upper elbows, which just clamp down onto an o-ring, but I expect there's a reason...........(

There are online models for calculating the flow. Yes, the joints seem a bit clumsy, but they are a very simple, economical and reliable way to do the join. And the 'rubber' end may serve to buffer vibration. It's not too hard to support or secure it all to avoid major vibration.

aviatorpl I have messaged you.

Hi PeterB, ICP who manufacture the Savannah have been supplying the metal hose with their kits since 2014, perhaps earlier. So far as I know there have been no problems with it, and I would think we would have heard if there was. As you can see in the pic, it is terminated with short lengths of 'rubber' hose. It certainly allows for a very compact installation.

I wouldn't conflate the service style with the product. My position would be that you're wanting to buy a good product to do the job reliably: if that comes via a less polished sales outlet, yes that's pesky, but does that effect the product?

Yep, it's a nono..........but can happen......

Curious. I asked because, thinking of the various Rotax powered aircraft at our airfield, I'm not aware of any having that failure. No doubt there will be a limit to the design output: I see 13.5A quoted. There is also a potential problem (no pun intended) with turning off the master switch with the engine still running, in which case the DC output spikes. Or that's my understanding, hence the fitting of the external capacitor, to take the edge off that. Will that damage the regulator, or is that principally to protect avionics etc?

Is it a common problem, though???

I would just go with the sheet metal: a simple job with material at hand and quickly shaped to bring the switch up to the right height.

Skippy, when you say 'extra careful grounding', presumably that includes the metal body of the regulator? I ask because I'm aware of one that appeared to fail (it hadn't) because the body wasn't well grounded.

sfG I cut a little disk to fit in the top of the tube (from one of the 6061 offcuts), with a little tab on each side going down into the tube, riveted these in place. Drilled hole for switch. It may have been raised in the centre to get the switch high enough, can't recall. Was a quick job.

Yep, horses go nuts with parachutes overhead. As do sheep: I had my legs taken out from under me by one just as my feet touched the ground. Nothing broken but it was like being hit by a small woolly train. I also once saw a fox running in panicked circles......

For anyone interested in the (nonstandard) 0.75 to 10.75bar bizzo, here is Dynon digging into it: https://forum.flydynon.com/threads/rotax-oil-pressure-pn-456180-definition-wrong.11767/ The final lines state Rotax 456180 is a standard 0 to 10bar unit, confirmed by Dynon physical testing. Which makes every sense.

I believe Rotax went away from the VDO unit as they are prone to failure: I have seen several replaced, and I don't get around that much. Pressure transducers or transmitters with 4-20mA output are a long standing industrial standard. Part of the benefit is that they return an accurate value regardless of how long the connecting wire is, which Voltage outputs don't (4mA anywhere in the loop will be 4mA, but 5v out there can be a lot less back here due to resistance of the wiring. However, that will not be a factor in light aircraft installations. I believe Rotax went looking for a more reliable replacement, and these industrial standards proved to be it.) They come in a number of standard ranges, one of which is 0 to 10bar. I don't think I've ever come across 0.75 to 10.75bar. That surprises me a bit and I don't understand why they would be 'nonstandard': typical ranges would be 0-10, 0-15, 0-25 etc, always round numbers. My Heavy Maintenance manual states 0 to 10bar and mentions either replacing the pump cover or recutting for a M10 x 1 thread (!) if upgrading sensor type. However this section of my manual may not be the latest version. There will be lots of 0-10bar sensors out there, but it will be a bit of a punt as to which will prove reliable in the Rotax environment of temperature, vibration and possibly pulsing pressure from the pump. If going that way, I would definitely be inclined to stick with the Rotax recommended unit. That or go with what you've got and reconfigure the EIS.

I have the standard ICP brakes. There is no appreciable 'give' in the pedals at all. I can't speak for the regulator or how that behaves, but assuming the system is full of oil (?) it seems very likely that the seals in the master cylinders are failing. My manual says in bold caps WE RECOMMEND THE USE OF MINERAL BASED OIL (DO NOT USE SYNTHETIC OIL TYPE DOT4). Or that's what it says after you translate from the ItEnglish that appears too often in the manual.............)

The ICP brakes in my build specifically called for mineral based fluid, not synthetic.

Ah.........I saw the Red Arrows in these at Strathallan in Scotland, late '70s. They had come out of Leuchars and since they had fuel reserves on completion of the display they then gave us individual high speed low passes. For some, this amounted to just clearing the farm fence at one end of the strip, then dropping down almost to the ground. Aircraft, teams and displays have moved on, but for me that was the best ever, a slightly raised airfield that allowed them to regroup below our horizon between manoeuvres and before those low passes, so that they seemed to appear out of nowhere........).

I return to my original suggestion: You have either periodic loss of fuel pressure, or periodic incorrect fuel pressure sensing. I would find out which by temporarily fitting a steam gauge. That cuts the problem neatly in half and points you to where to start looking: instrumentation or fuel system.

I would not pressure test the wing tanks in situ, as they sit against the upper skin, and even minimal pressure will exert a considerable force, bugging out the top and the bottom of the tank. I don't have the exact tank size, but eg: if it's 20" x 20" that's 400 sq inches. Give it 2PSI and that 800lb over that surface area....

I did not test my cooling system, but went looking for any leaks are drips following initial engine runs. For fuel, the Facet pump has a non-return valve. I did my initial runs with wings off, so had the fuel return line blanked off, and that part of the system held pressure on the steam gauge after the pump had been run then turned off. (Incidentally, on normal prestart you are looking for that pressure to fall away quite promptly once the Facet pump is off: this tells you that the fuel return orifice is clear and doing it's job.) I would be getting some gravity feed from wing height down into the receiver tank. Mine developed seepage from one of the tank top connectors and that wasn't evident until it began to wet the sides of the tank. So I would be looking hard at that area. For the oil system, there is an essential Rotax priming procedure to push oil round the system after engine installation. This involves light pressurisation of the oil tank while turning the prop many times, and would allow you also to check for leaks.

Jeeze guys! Put the valve in, pump 'em up, and go flyyyyyyyy............)

sfGnome that looks like half a wheel. How does that work as tubeless?

Run it past the agent, or ICP themselves if he can't answer. The problem with tubes is that under certain pressures the tyre and tube can rotate round the wheel when braking, wrenching the valve in the tube.

Don't fit tubes!!!!!!!!!!!!! We envy your tubeless...........)