skippydiesel

1 hour ago, Thruster88 said:

I would buy a replacement, $30-50 aussie from aircraft spruce australia. Depending on which type you have the o-ring could be replaced and you will have a spare. The flush, cessna style, look like they are sealed for life.

These are new valves - they should not need to have the o-rings replaced but if all else fails I will certainly replace them in the hope of a fix😈

11 hours ago, Moneybox said:

You most likely have a bit of sediment in the tank. Try opening them fully a couple of times to hopefully flush it enough to seal the contact area.

Shouldn't have but wont discount completly;

• Tanks were well flushed before test flights.
• ALL fuel is passed through a Mr Funnel
• In 195 hrs, no contaminants appear in pre flight fuel drainings

I have tried a prolonged drain/flush  no improvement. 

Next time tanks are empty, will remove drain valves and attempt a clean - see what happens.😈

12 hours ago, Blueadventures said:

Don't fly while dripping fuel leak under a plane, back fire on start up, small pool of evaporating fuel and light breeze wrong way and you have a fire possibility.  Happened at Proserpine to an RAA aircraft a few years back.  I don't like the push up steel (get rusty) ones, not uncommon to leak and need replacing.

Thats an ATEC Zephyr and the initial fire is concentrated in the engine bay - not the fuel tank area.😈

29 minutes ago, djpacro said:

I've had the same problem with new drain valves. Take them out and clean them - dirt or a burr is enough to open them enough to leak. Have a friend with you to stick their finger in the hole or have a plug (perhaps an old valve) ready to screw in.

Or use up all the fuel - just topped up the tanks today, so will be a while before empty.

This should not happen though - must be a crap design if so easily defected.

Will try your suggestion - nothing to lose except the staines and very slightly lower fuel consumption.😈

My Sonex wing tanks have SAF-AIR push type fuel drain valves.

They leak or rather they weep very slowly.

The whole aircraft, including valves, have only done 185 hrs in about 2 years and the valves have been leaking for most of that time.

I make a point of pulling each one down after every preflight drain – doesn’t help.

The weep is so slow that this is more of an aesthetic problem – stains on my wings, than any practical issue.

All helpful suggestions welcome😈

Weather forecast for heavy rain this arvo - sky looked inviting this am, so went up to try out my Bluetooth headset adapter & AvTraffic.

Small problemo, no small aircraft flying in the Sydney Basin. Very unusual. I guess the weather forecast made everyone stay at home.

Tooled around enjoying myself, for 1.5 hrs,  in the hope of finding an enemy aircraft - no luck,  so no report on system efficacy.

Next time 😈

36 minutes ago, Thruster88 said:

The obvious would be to move the engine back to help with CoG. 

True!

However there are sometimes other reasons. Its not unknown for aesthetics to be one, air flow, prop clearance (nose wheel), etc

What weight is the Zonsen (?) compared with the origional Jab?? .😈

2 minutes ago, Kyle Communications said:

The idle sounds and feels better...cant quantify it any better than that.

 

 

Thats great for those who value such.

Without empirical evidence AND most importantly, a clear engine operational benefit, it strikes me as being a faith based investment.

This concept has been vigorously debated, in the Rotax Owners Forum, over about an 8 year period.

• No empirical evidence has ever been presented.
• No improvement to normal engine management has been shown, bearing in mind that most Rotax 9s spend every little of their operational life at idle (purported to be the main area of improvement).

https://www.rotax-owner.com/en/general-tech-discussion/6709-polishing-intake-manifolds

Given the simplicity & potentially low cost of this concept, why has Rotax not adopted it as a standard fit or offered it, as an after purchase, performance enhancer?

😈

Ho Kiwi,

Your twin engine manifold pressure/vacuum  gauge is a great idea - wish I had one.

I guess its likly to use two Bourden tubes to deliver the readings, so not so diffrent from my two gauge motorcycle carby balancer, just more compact.😈

Hi Rapture,

"Our prop spacer arrived a couple of days ago."

Aside from the obvious,  moving the prop forward, what is the purpose/benefit of having a prop extension in this installation?😈

Hi Kyle,

"The larger balance tube does give a better idle performance...... "

Please quantify - what is "better" about the idle and what is operational advantage  of this improvement over the  OM design?😈

Hi Blueadventures,

"I have the Synchromate and also a tube unit."

Is this, a sort of answer to my "Do you follow, as per Rotax advice, your mechanical carby balance, with a pneumatic balance?"

 ie you have the gear, so am I to assume, you have used it?

I Googled Synchromate carburettor balancer to try & get a handle on the equipment you may be using to do a pneumatic carby balance - nothing!

Well not nothing, Google always gives something;

Synchromate refers to a veterinary injectable medication containing the synthetic hormone cloprostenol, primarily used in livestock (cattle, horses, sheep) for reproductive management like synchronizing heat cycles, inducing ovulation, terminating pregnancies, or inducing labour.

There is a more likly contender;

 TecMate SynchroMate (TS-101), for synchronizing carburetors or throttle bodies - is this it?

There was also something called a SynchroKing, which may be similar to your TecMate - all pretty pricey.

For what its worth; The Rotax Owners Forum technical advisors have opined, that the above type devises, are not as good as a simple vacuum gauge, for balancing carburettors.😈

52 minutes ago, onetrack said:

Has this website turned into an auto forum? I saw someone complaining about another poster talking about car engines, and that someone roasted the other poster, and told him to go to an auto forum!

One of the attractive features of this Forum, is the wonderful tangents the conversation can go to, without people getting all huffy about adhering to the origional topic.

Sure it can be frustrating, if you are after targeted advice - most often a gentle reminder, will bring the responders back on topic.😈

Hi Blueadventures - Third attempt to get a bit more information

• The above statement, (now further back) mentions mechanical carby balance, what of the pneumatic balance???

Common Mate what's the big secret? 

Do you follow, as per Rotax advice, your mechanical carby balance, with a pneumatic balance?

If not, why not?😈

44 minutes ago, FlyBoy1960 said:

the pneumatic ones made by Carbtune are really good, they used brass rods and didn't bounce around like gauges. I have also used a digital balancer from Aircraft Spruce called the carb mate  https://www.aircraftspruce.com.au/catalog/eppages/ts111kitcarbmate.php    it seemed to work really well also

 

I have used a pair of cheap (Asian made) twin carb motorcycle vacuum gauges, for about 15 years now. They are excellent!

Come with a little adjustable valve for each tube, so that the needle pulse fliker/bounce, can be "removed".

The "face"/ needle, can be zeroed if needs be.

I had to purchase longer vacuum hose, so that I can have the gauges in the cockpit, while engine running.

I always swop tubes, to assess consistence of reading - so far no discrepancy.

Can't understand why people go and purchase expensive digital/electronic stuff ($500++?) when something like this is all the owner maintainer will need.

($21-$51) 😈

Hi BrendAn,

I stand to be corrected; - Mercedes have never made a 190 car. They have made a series of 190 engines (190, 190E, 190D, etc). The 190 refers to 1.9L. The car, the engine is fitted to, wil be  a W??? 190?😈

Hi Blueadventures - Second attempt to get a bit more information

• The above statement, (now a few back) mentions mechanical carby balance, what of the pneumatic balance???😈

58 minutes ago, BrendAn said:

912is  does away with all this drama

The origional carby one will do me nicely. 

As I understand, the injected varient of the 912 has two advantageous over the same carburettor engine;

• Better fuel econamy
• Greater (total?)  resistance to inlet ice.

The disadvantages are significant;

• Much more expensive to purchase.
• Greater complexity - almost impossible for the average home mechanic to do anything with the fuel delivery throttle system. Potential to be very costly if goes wrong.

Repeating what I have read-

The 912is fuel savings;

• Could take the average owner/ pilot near 20 years to equal the greater purchase cost.
• Are possibly attractive to flight schools/hire operators (fast hour accumulation), assuming the sale of high time engine is attractive to 2nd hand purchasers.

😈

I had  Nissan Skyline , bought 2nd hand, back in the early 1980's Not sure but think the engine was 2.4L.

Car all Nissan, disk brakes, independent suspension & very nice to drive - engine looked to be almost an exact copy (less the star on the rocker box) of a Mercedes.😈

Hi Blueadventures - The above statement, mentions mechanical carby balance, what of the pneumatic balance???😈

Just like the Japanese indeed - they only improved a design, where they think its worthwhile to do so.

A Big Balance tube serves no practical purpose, other than to lighten the wallet (this topic has been thoroughly discussed, elsewhere on this and the Rotax Owners Forum - its a gimmick!)😈

Hi Blueadventure,

Can't quite work out, are you are for, fence sitter, against, the Big Tube (BT)t??

Say for a moment the BT does what its supporters claim - smoother running and lower rpm. 

• Starting with rpm - Rotax advise against extended low rpm operations as this will almost certainly damage the gear box - So no benefit!
• Smoother running - Without data this is just a perceived benefit. Nothing wrong with perception but when you are trying to promote a product/modification, I will always want data ie proof.
• Then you need to consider the engines state of "tune" ie Was the engine that the BT was fitted to,  recently serviced,  carburettors balanced, plugs in good condition , etc

On the last point, if the BT  smooths out a badly running engine, this is a good thing - assuming its not masking an impending problem.

I am not an engineer, however my understanding of the Rotax balance tube is that its there to smooth out/make good, any small differences in vacuum between the two induction systems. No significant volume of air flows back & forth in the tube. The proof for this is simple - when doing the pneumatic carby balance, you run the engine with the balance tube disconnected/shut off and the engine runs just fine (smooth) when carby's are balanced.

Fitting a BT, will not improve on the action of the Rotax balance tube.

I am certain Rotax would have adopted such a simple enchantments if it works as promoted.😈

This  "modification" has been extensively discussed on Rotax Owners Forum.  Latest revival can be found at https://www.rotax-owner.com/en/general-tech-discussion/6709-polishing-intake-manifolds?start=50

My summary of the discussion:

• Supporters rave about perceived smoother running /lower idle speed
• No empirical supporting evidence.
• Most can't see how it can work/make a significant difference to engine performance.
• A few die hard supporters refuse to believe its a con job

Note; that Rotax engines should not idle below about 1400 rpm, as gearbox damage may occur, recommended extended  idle 2000-2500rpm😈

"Tomorrow"  turned out to be 8 days later (yesterday). Did an hour. Bit warm under the bubble ( 20C @ 5500')

AvTraffic a non starter,  due to this computer luddite not realising that a whole heap of "stuff" needed to be selected ON (hope I have now done it correctly). Will do a review after the next flight.

For now - Noticed a  change in my intercom;

• Volume needs to be turned to Max, then turned down on headset.
• I usually do a "click" check, short press of transmit button, on my intercom - doesn't work any more - cant hear the click.
• Cant explain it, but headset/intercom seems dead - to the point where I did an Any Station Radio Quality Check  - came back 5/5.
• This is the Six Aviation Bluetooth Adapter - not the AvTraffic

Should not be related, iPad / WiFi connection with my SE2  dropped out ??

Also lost OzRunways traffic (blue bubble) alerts, for a brief period?? The third event of this nature.

I also noticed,  after trying, unsuccessfully , to "fix" the AvTraffic issues, in the air, my OzRunways was very slow to come back on ??😈

9 hours ago, danny_galaga said:

Many, including me, use this design, from K & n

 

https://www.knfilters.com/re-5287-universal-rubber-filter

The above has a 2 3/4" flange.

FYI: The similar  filter, with a 2 1/2" flange,  K&N part # SN-2540, used by many Rotax 912's,  may have been discontinued.😈