I pressed on with stripping out the Savannah panel today and succeeded in getting everything removed save for one recalcitrant screw holding the small rev counter that I want to dispose of in the panel front. Everything else was out by the end of the afternoon and I lost just one gauge, an AVD temperature gauge with a plastic body that broke when a securing nut tightened up on one of its mounting bolts and wrenched the bolt out.
Unfortunately the gauge has now been discontinued and an initial search has revealed that the ones available on line all come complete with the temperature sensor at prices not far short of 200€. So that’s a big disappointment and I think that I’ll have to start by seeing if I can repair the gauge casing with Araldite or something similar, much as I don’t like the idea of doing that.
Here’s how the panel looked at the end of the day.
So what about the piece of good fortune? Well, I got the Savannah out of the hangar a few weeks ago for the first time since I last flew it in December in order to start it up and give the engine a run. I found that it took longer than usual to start and when it had done, it seemed to be running a bit rough. But the worst thing was that when I increased the engine revs from idle, it initially began to shake rather wildly until the revs had built up to a certain level.
It had never done that before, and in fact since fitting the new scimitar blade prop, the engine has been running very smoothly indeed. On that day, I left it out for a few hours in the warm sunshine in case the problem was due to its being in the cold, damp hangar over the winter.
I didn’t restart the engine that day but I did the other day before I began to strip out the panel and this time the problem seemed to be even worse. Even before the engine had a chance to warm up I turned it off because the shaking was so bad that the whole of the nose seemed to be shaking as well and I was concerned about doing damage to the engine mountings.
I need to get the panel work finished so in the meantime while I’m doing that, I posted on the microlight forum asking for ideas about what the problem might be and the suggestion that rang the most bells and seemed most plausible to me was perished carburettor inlet rubbers.
Before leaving home today I checked through 77ASY’s papers and could find no information about when the carb rubbers might last have been changed. My guess is that if they have been, it was at least 5 years ago and probably more, so even without checking them more closely, just for my own peace of mind, I ordered a new pair before leaving the house. And lucky I did because before I left Malbec this afternoon, I wiggled the left carbrettor and it almost fell of in my hand and probably would have done if I’d kept on wiggling it.
So how lucky to discover that before taking off for my flight to the UK. And with hindsight, how fortunate that my last flight back at the end of December went off without incident, because on that occasion I was carrying a precious cargo – Wim’s granddaughter Danni. It just goes to show and makes you think, doesn’t it 😐