I’m just going to put the video right here
So this one has gone quite long – short version, I started the engine, there was no oil pressure so had to stop. We think we know why.
Jet lag, heavy rain and a bunch of stuff going on meant Saturday was a very short day. First I put the freshly repaired iEFIS back into the panel, powered it back up and everything still works and the new custom screen that MGL made for me hits the spot.
The firesleeves had arrived so I tried to get those onto the hoses – this is impossible with just one pair of hands. The best solution, it seems, is to blow compressed air into the sleeve and push the hose down. I didn’t have a small enough adaptor for the air so had to blow it up from the bottom and put my thumb over the hose end. And push. Turned out to be impossible to get all the way through but fortunately Allen popped in for a quick look and we got it in. So now the fuel pressure line is sleeved and installed on the fitting.
We’d have the same fun on the holiday Monday with the fuel return line but it finally made it on. I need a small hose clamp to secure one end of the line.
With not a whole lot that can be done until the forward skin is on, I set about putting some stripes on the side. I’m hoping these will break up the two mismatched whites. Anyway I laid out where the first stripe would go, made a template and stuck the first one on
I made a few copies of the template without stopping to think that the fuselage gets wider as we go forward! I blame the jet lag, but either way the copies are trash and I will need to make new ones as I feel the urge.
With all the gauges working etc there really were no excuses for not starting the engine so on Monday, Allen’s son Scott joined us and Teri came along to share the excitement. I pulled the plane out (love the tow bar!)
and tied it to our pick up truck.
From there it was just a case of enabling the required electrical circuits, choke out, throttle to idle and crank the key. I’d never started a Rotax before so although I had read the instructions and seen a couple of videos I didn’t really know what to expect. But as you can see from the video, she would have started up first time if I had kept the starter engaged.
When she did start, I had the pushed the throttle too far in – you can see the plane lurch forwards before I set it back a bit. I ultimately set it back too much as the engine came to an idle stop. So, after a deep breath, I repeated the process and got it mostly right I think. I had the engine back at about 2000 rpm before I noticed that the oil pressure was reading 0 and so I shut it down. All the other gauges were reading reasonable values but you have to to have oil pressure!
This was unexpected since we’d had oil pressure a couple of weeks before. To test it some more we hooked the starter to the battery again and still no pressure. I checked the settings on the panel and they seemed ok, the only conclusion then is that we had air in the line (or other problem). So the plane went back to the hangar.
The first start instructions say that if oil pressure is not observed then to repeat the purge of the oil line, which we did. After the oil started coming out I checked the panel and it showed 2.9 psi. Another test with the starter and the battery showed that oil pressure was being measured again. Why we lost oil pressure when we had some earlier is a mystery and so I will reach out to the boards.
Except…. part of the start process is to ‘gurgle’ the engine, you remove the oil cooler lid and turn the propellor 5-50 times until you hear a gurgling sound. I’ve tried this 3 times and never heard the gurgle. I thought the main purpose of this was to bring oil back into the cooler so you know the true amount of oil in the system and don’t put more in when you don’t need to.
But another part of this process is to burp out any air in the system (how air gets in there I do not understand) so I think by not doing this successfully, the engine was not in a state from which to start safely. A person on the Zenith builders site told me that he would never start an engine that couldn’t be gurgled because “there might be air in the line”.
I shared the instructions with Allen and he noticed that the key thing in the process is to get compression that forces the oil (and air?) through the line. Well, this means the spark plugs need to be in and each of the times I tried to gurgle the engine, the plugs were out. So…. I’m hoping this is the crux of this problem.
Next hangar visit I shall try it the proper way and if we get a gurgle I think we can try another proper start.
I have to admit that I was quite terrified sitting in the cockpit alone about to start the engine. My helpers had all retreated to a sensible safe distance and I really didn’t know what to expect. But even if was just for a couple of seconds, the engine roared and I could feel the power wanting to take me for a ride.
A milestone day!