IBob

I've specified expansion vessels for a few closed loop boiler systems. It's been a while, but as I recall we used to budget on 4% expansion, from ambient to 100'C. I can't now recall if that was the actual expansion, or expansion plus safety margin. Water coefficient of expansion is not linear, so you can't just plug one number into the usual calculators.......

I recall a comment from a LAME with a lot of Rotax maintenance experience: he said that almost all the carb balancing problems he came across were due to poor installation and/or maintenance of the cables and linkages. I have only worked on one Rotax (my own) but went to some trouble to set that all up with swept cable bends etc. Some minor cable adjustments were then required in the first 50hrs, thereafter I still checked regularly but no further adjustment was required.

For smooth idling etc, first check the throttle stop and idle jet settings as per the manual. These are static adjustments and about 5mins 'work'. One of mine was out on a new 912 (can't now recall which one), so worth checking regardless. After that, synchronise the two throttle actions.

Thanks, red. I continue to enjoy seeing them. And I continue to be astonished at the sheer number there have been........

Nothing wrong with capitalising on your assets.........)

Unfortunately, birds seem to habituate to any static deterrent if there is food and/or nesting space. They are a perennial problem in vineyards. Netting of the vines has greatly improved in recent years, but prior to that vintners tried all manner of things: kites, balloons with big fierce eyes, gas guns, hawk cries. And this: An engineer in Hawkes Bay had a bright idea, persuaded a local vintner to let him try it. They erected posts with pulleys on top round a vineyard. An endless motor driven cable ran round the pulleys, and the idea was that various scare devices (balloons, kites, flashers and noise devices) could be attached to the cable and would move constantly round the vineyard. A couple of weeks after all this went in, the vintner called the engineer and said 'We have a problem, you're not going to believe this'. The birds, and there were many, had taken to sitting on the wire, and were happily riding round the vineyard, diving down occasionally whenever an especially juicy bunch of grapes hove into view...............

Ah, you're a week early, flymate: next week end 13/14 Dec is the monthly fly of the Vintage Aviator machines at Hood airfield, Masterton. They wheel out about 20 WW1 aircraft, crank them up and fly them.......

That'll be this one:

I thought this was a pretty good watch:

It's not unusual for pilots of jump planes to wear a parachute......I would say because there are very occasional incidents where a departing jumper damages the aircraft. Perhaps he was wearing a parachute and attempting to exit.

Hi Marty......all sounds like progress! FWIW: My front CHT always read lower than the other one: probably inevitable given the position of the sensors. I think Rotax now recommend initial warmup at 2200RPM, dropping back to 2000 after a few minutes. And my 912 always felt better at 2200 when cold. And I'm not sure about 1800 as the min setting. Mine went lower than that, which was kinder to the engine/gearbox when finally stopping (no big clunk). I set my idle jet and throttle stop as per the Rotax manual, it's quick and easy and one of them was out on a new engine, so worth checking.

I didn't, Skippy. I know MEK is just about instantaneous compared with thinners. Is isopropanol similar?

Other things keep coming back to me: The manufacturer's printing on the 6061 needs to come off, or it will bleed through. Thinners will do this, but MEK does it far quicker and cleaner. However, MEK is nasty stuff, so needs handling with care.

Also this: the polycarbonate in my doors still had it's protective peel-off coating. I then added a thick layer of paper, fastened round the edge with masking tape. This turned out to be totally inadequate, as when I removed those, the surface of the poly was lightly fogged. Presumably paint solvents had made their way through. I believe what the professionals do is mask this stuff with some sort of metal foil and tape. No doubt someone here can tell us? It gave me a bit of a scare: the door is basically two poly panels with a huge number of rivets round the edges and across the middle. But I was lucky (that time): the fogging was 'only' surface and I was able to remove it using a Meguires smooth surface clay kit and a great deal of elbow grease.

Some other bits and pieces for those coming at it for the first time, as I did: My assembly priming was done with a cheap gun, but when it came to the final job, I bought a good quality gun. They just do work better. The wing side I had to wash back and repaint went on too dry, and the reason was too much air. I bought an air pressure gauge that goes on the gun, as the pressure at the compressor is not the same as at the gun once you start spraying. This allowed me to set the pressure at the gun correctly. I had a mixing table in the booth, with a DIY stand for the gun. For mixing I used straight sided pots and a measuring stick to get precise mixing ratios. The measuring sticks are available at spray shops. I then used fine mesh disposable filters (also from spray shop) to filter the mix. I wore a (disposable) lightweight suit, with hood, and neoprene (?) gloves. My mask was 3M full face with Organic Vapour cartridges. This has a neat setup whereby incoming air comes via the face, but outgoing air does not, so there is no misting up. I also bought disposable particulate filters: these go on the outside of the cartridges and catch the overspray, which will otherwise quickly block the (expensive) cartridges. Also from the the spray shop: Tack cloths. Masking sheets (for masking off big areas). These come in a dispenser with adhesive tape attached to one edge and are far quicker and neater to use than DIY solutions.