skippydiesel

Rotax recommended temperature range are for the Rotax location of the sensor. By placing a sensor in a non Rotax location you are on your own ie what significant is there in your auxiliary sensors reading??? Liquids in an IC engine will experince diffrent temperatures in diffrent location's. What matters is, the temperatures are within the Rotax recommended range. Coolant getting to 100C, on extended high power Climb/TO seems to be quite acceptable to me. The engine oil should also get to at least 100C, for an extended period (20min?) once in every days flying. If not getting there, you should consider blocking off part of the Oil Cooler. I do this every winter (temp consistently below 25C). I use aluminium foil, adhesive, air conditioning tape, to do the blocking. Be cautious, only block off a small area at a time (eg two bars of the cooler). Go fly, check oil temperature. Once you have found the correct amount for your engine/climate, take a photo for future late autumn reference.😈

??? Not sure why you felt it was necessary to post this again. 😈

FOLLOW UP - Purchased new Viton "O" rings to suit. Flew aircraft until wing tanks empty. Removed drain valves. Valves found to be heavily contaminated with what appeared to be paint flakes. Cleaned & replaced with OM "O"rings . No leak/weep. Investigated source of paint flakes. Seems likly that came from area around the fill point. No weep or leak for the next 6 months. A few days ago noticed minour fuel staining, behind left wing tank drain. Tried to flush, by repeated draining. No sign of contamination, continued to leak,. Tried the "pull down/little twist" after seated, to no benefit. Removed drain valve, caught the 6 L in the tank, in two jugs. Could see some contamination in bottom of one jug. Once again "O" ring had some very fine particles adhering to it (nothing like the first time) This time replaced "O"ring with new. Replaced valve. Filled tank - no leak. I think I made a mistake on the first "repair" - should have drained fuel from tank, to flush out any remaining debris. I expect the right wing tank drain to give " trouble" sometime in the next few weeks. Now that I have some experince with diagnosis, cleaning & repair, its not a big job. Removing/relapsing the "O" rings is best done using a mechanics bent/hook pick and some silicon to ease the process. 😈

Agreed! I don't often consider the insurance /warranty angle, I just like to do the right thing for my aircraft/engine & my safety. As you & the other Forum members know have a (very) questioning personality. Whenever reasonable to do so, I will go a cheaper parts rout, subject to meeting/exceeding specifications ie I don blindly follow Row Tax marketing propaganda. However I find the questioning of Rotax advice on the use of AvGas and the resultant increased servicing/maintenance recommendations to be absurd. Rotax do not gain by advising their 9 series engines prefere ULP and need extra care if AvGas used. If anything its a negative point/feature (referred to by the Rotax knockers). I have seen, (Page 5 below) photos of the lead ling inside/components inside of a Rotax 9 . I didn't need to see it, to believe the Rotax advice - it's been consistent/unchanged for well over 30 years. Adding to this is the resent Rotax development of a full synthetic crankcase oil, that will handle lead contamination from AvGas - why bother if its not an issue. http://southernmicrolightclub.com.au/linked/912 maintenance article - inc carb bal.pdf 😈

I cant make an informed comment about your Jab engine, however in the past, cars exported from Europe/UK where high Octane automotive fuel was available & specified, often had their compression ratio reduced (thicker head gasket/spacer)to facilitate the lower octane fuels then available in Australia. My home airfield is over run with Jabs. I stand to be corrected, they run on 95 - 98 RON automotive fuel.😈

It must have been a very "quick search" indeed & why images ? when Rotax are quite specific about the use of AvGas. I doubt if there is a Rotax owner who does not know of the increased service/maintenance requirements, due to lead, when running the 9 series engines on predominately AvGas. My quick search revealed the following: "The official advisory and technical guidance for using leaded AvGas in Rotax 912 and 914 series engines is outlined in Rotax Service Instruction Rotax Service Instruction SI-912-016 (Selection of Suitable Operating Fluids). Leaded fuel increases lead deposits, spark plug wear, and oil sludge, requiring tightened maintenance intervals if used for more than 30% of operating time. " "Oil and Filter Changes: Must be reduced (from 100 hrs) to every 50 hours (or ideally 25 hours) instead of normal intervals when running mainly on leaded AvGas. " "Gearbox and Clutch: Extra wear checks (@ 600 hrs) on the overload/slipper clutch and removal of lead sludge accumulated in the crankcase and oil lines (ULP interval 1,000 hrs)" Further a read of the 912 Service Schedule, will back up the above statements.😈

Be very careful about assumptions about LAMES maintaining Rotax engines. I have met LAME's who knew next to nothing about Rotax engines and further more did not want to know. So closed minded are some , I know of one instance where the training organisation, acquired a Rotax powered aircraft, to offer cheaper flight training. The LAMES refused to mainatine it and the school had to sell it off.😈

Thanks KG, I don't know very much about Jabs however it seem to me, when using AvGas, they do not suffer from the lead fowling that Rotax 9 devlope.😈

You must be looking at a diffrent document - The one I referenced (opal-factsheet-storagehandling.pdf ) has no date. It just reads as a more up-to-date/resent document than yours.😈

I am paraphrasing Rotax recommendations, which for aircraft used for hire/reward (training) are a requirement ie non negotiable. Whoever owns the aircraft, you referenced will have higher operating costs, than a similar ULP power aircraft - no doubt passed on the the customer/students. Has nothing to do with my qualifications, skill set, knowledge. There are plenty of Rotax 9 users who do use AvGas (seems to be quite popular in the USA) however they accept the additional costs associated with their choice. From my reading, various N American based forums, obtaining ULP without ethanol can be difficult - this, convention & convenience (AvGas being readily available at most airfields) may be the reasons. 😈

No offence intended - This is a misleading statement. The engine may not be bothered, however its owners should. Rotax advise that when using more than 30% AvGas in their 9 Range additional servicing/maintenance is required. Rotax 9's are designed to run on ULP. They will run on AvGas, with additional servicing/ maintenance required, due to lead build up within the engine/g box. There is no performance gain with AvGas below 10,000 ft and above that, marginal. Avgas usually very much more expensive than ULP. Current fuel prices, due to middle east wars, may reduse the margine. From imperfect memory - When using AvGas at above 30%: Oil changes reduced from 100 hrs to 50 hrs ie twice the cost. Gearbox inspection reduced from 1,000 hrs to 600 hrs ie almost twice the cost. 😈

Please clarify - are you using more or less than 30% AvGas in your Rotax?😈

I suspect that fuel, designated for aircraft, has a lot more associated paperwork (=$$$)😈

It’s not where you start your working career, its where you end it. I know a person, who started working life as an apprentice electrician. He retired as QANTAS Chief Check Pilot .😈

I don The reference made has no date on it, however by my reading seems to be more recent/current; https://www.bp.com/content/dam/bp/country-sites/en_au/australia/home/products-services/fuels/opal-factsheet-storagehandling.pdf 😈

22 Aug 2026 08:00 End 23 Aug 2026 16:00 Location Leeton Aerodrome, NSW https://antique-aeroplane.com.au/event-6763119

Couldn't watch all the way through, so hope the impression I got, has not been appropriately addressed later in the video - BS! This system may do something about light turbulence. No way will it address the the rough stuff or the powerful up/down drafts that can occur when full power has the aircraft still descending and idle has it continuing to assend. 😈

With nothing other than experince to informed me and the assurance of the established fuel companies (BP, Shell, Ampol, etc) - Your questionable statements: "Stale fuel can stuff lawnmower carbies..." In the 50 or so years that I have been cleaning fuel gum/varnish out of carburettors, mainly small engines (4 & 2 /) I have yet to replace one. On occasions, gasket, diaphragms, etc but never a whole carby. "...the lower level octanes (cheaper) contain ethanol..." This is urban myth, without foundation. In Australia 91, 95, 98 RON does not contain functional quantities of ethanol. Any traces of E, are due to transport contamination & likly amount to well under 0.25% by volume. "Highest level octane has no ethanol but the aromatatics evaporate off to the point where you can't start the engine." - This is an exaggeration. While it is true that 98 RON fuel, looses its volatile fractions quicker than 91 RON, in all the years that I have using 98 RON in my Rotax 912 ULS & had starts that were not quite as immediate, as when the fuel was fresh, there has never been a hard or no start situaton. 😈

Thought you might. I have actually travelled in a Bristol Wayfarer - I was a child, so only memory fragments - saw a car being loaded into the belly/hold. 😈

I am flattered (I think) that you fantasise about my presence on this thread. Truth is, in my ignorance, I neither popped or entered - not knowing what a MSFS (2024) person is or looks like. That was until Rodgerc enlightened me. Family myth, has it that my parents went down this track, I on the other hand had to expend much time, & hard earned cash, to win over my bride.😈

Beauty (nice) very much "in the eye of the beholder". What do think of the: Short Skyvan or the Bristol Wayfarer 😈

Ill give you the TAS on my trusty Garmin - but not hard to estimate TAS based on altitude and indicated airspeed - just add 2% to indicated, for every 1000 ft.. Anyhow, the core of my argument is simply that, asides from significant weight reduction, the glass screen does little if anything to add to the pilots safe/efficient operation of the Day/VFR aircraft. When purchase cost and reliability (repair/ update cost) are added, the screen becomes even more suspect. The glass screen is the way of the future - not apposing, just pointing out its allure is far greater than what it actually delivers (much like all the extraneous crap fitted to cars these days). 😈

Very nice - but did not address/answer my question.😈

Not in the habit of delivering hollow platitudes - I asked a valid question of what appears (I may be wrong) to be a draggy, fairly low powered aircraft, that has had considerable weight & drag added, so that the proud owner can land on water or terra firmer. I ask again - How may this have effected it's performance, in particular its range? The true believer acted with predictable aggression but no answer and you my friend would seem to have bought into his dogma. While I am all for personal faith - trying to convince others (yourself) that the utilitarian Savannah is "nice looking" is ridiculous. Its a very popular aircraft, for many good reasons, but nice looking??? - you jest.😈

I support free will (in most circumstances) - your prerogative my friend. What sort of engine and does your aircraft /fuel delivery system maker, approve of Stabil? 😈