rhtrudder

It's not unusual for a thermostat to "hunt" but if your cap isn't maintaining the correct pressure it's possible you will get some steam pockets especially at altitude. That will explain the coolant displacement and the varying temp indication. You must be sure the cap is the correct one. and the part of the radiator where it fits is not damaged. . Pressure test the system. Nev

Either would be OK . (Not mixed tough). The Particular green one I use is a long life one. (concentrate). Nev

I think the red nulon is more anti corrosive but not as much anti freeze which l thought was better suited, did use de ionised water, thanks for all the advice and l will have to look a bit harder

The overflow/recovery/expansion bottle is NOT pressurised

 

Have no experience of Nulon (red or otherwise) coolant leaks however the Rotax recommended Castrol Radicool concentrate (not pre mix) leaves a "chalky" residue when it leaks.

 

I would strongly suggest you flush your engine cooling system and refill with the recommended coolant at the recommended ratio (1:1) of concentrate to "pure" water.

 

This ill not fix an existing leak but may give you an indication of where its is AND returns your engine to the Rotax standard.

"the bottle"

 

Plastic bottles do become porous , & leak only under pressure.

 

spacesailor

Been using a red coolant, looks the part, put water in at tilpa, that’s all l had, engine ran a bit on the cold side on the way home

All good suggestions - almost all leaks will show a "tell tail" IF the recommended coolant & correct coolant concentrate to high quality water ratio has been used (50:50).

 

Question: when Rhtrudder filled up "the bottle" did he use the Rotax recommend Castrol coolant or plain water ???

Pull the cowls off and ground run it. Once it's up to temp you may be able to see the leaks.

 

If it's leaking past the pump seal you will see it at the weep hole at the back just in front of the water pump on the bottom.

 

Check your cap is sealing properly and that the elbows in the heads aren't weeping. Check your bottle overflow in case it's syphoning.

 

Important to get temps up so the system is pressurised, otherwise you won't see the leaks unless there is evidence of coolant inside the cowl.

rhtrudder - Usually, any coolant leakage past the water pump seal leaves a visible trail, after it's dried. Have you considered that a head gasket may be leaking coolant into the exhaust?

 

Have you considered doing a static cooling system pressure test to see if there's a pressure drop, and to see if you can spot any leakage? (while the system is pressurised).

Having dramas with disappearing coolant from my 914 , changed every hose replaced the clamps with the spring type , then don a 14 hr trip , all good , flew up to tilpa from echuca, about 2.5 hrs , bottle empty, filled it up , came home this morning, 3.5 hrs , headwinds, bottle empty, driving me nuts, is there a chance it’s leaking past the water pump seal, not a easy fix, read somewhere it can leak in the cold weather, can’t see any visible signs, anyone come across this?

Thanks for your replies, that was the one , I thought it was a good idea to, take all the weight off the controls

Came across a ap a while ago that used a small servo that controlled a trim tab mounted in the aileron , anyone know who made them

I don think anyone doubts the improved fuel efficiency of the 912iS - what is debatable id the cost effectiveness of purchasing an iS, compared with a ULS, for most RAA users. Flight schools and other high hour (fuel) users may be able to justify the significantly higher cost of an iS as their break even period may be only a few years.

Agree. Bit like driving your private vehicle to work each day, raa plane should be judged same for similar use. Bulls comment would apply if doing a regular, payed (not share ) transport to work of a passenger in a RAA aircraft.

Talking to a bloke at echuca fly in for roast day last month , he built a really great sling 4 seater powered by a 914 but at 110 cruise it burnt 28 litres two up, I know it is a lot more plane than my Sabre which uses about 18 at around 120, I reckon it was maybe underpowered.

Everybody knows Cliff, the PM has me confused as well but I will keep trying

Fly off our farm strip , near echuca, have flown to flinders and Devonport via king island, lot of desolate country once you head north west , flinders rangers onto Birdsville back home via white cliffs,if you get over this way let me know and I will guide you in

Never got off the ground , all the starters piked one by one , really need some escorts on these sort of trips just to keep a look out for each other, I’m always keen to fly anywhere so let me know if your happy to have another flyer to be apart of the sortie

Thanks Alf , I’ll pass it on .

Unsure , but I will find out , plane is a Europa, the one with the mono wheel and two wing stalks, gets along pretty good , thought the problem might have been a throttle cable hanging up but thinking about it the cables are pulling the butterflies closed when throttling back

You might be on to something, sort of sounds like fuel, thanks

have a mate with a 80 Rotax , at cruise , 5200, when he backs off the throttle a couple of hundred revs there is a slight miss but then settles down , does every time , l thought it was to high in the rev range to be carby balance, any ideas,

Thanks for that

It does have a cap fitted and I did wonder if it was the culprit, doesn’t seemed to have lost any voltage after two days so maybe okay

Have multimeter, rough idea how to drive it , thanks for the reply