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Hi JR, I just used a motorcycle static wheel balancer. I fitted a bar (smae size as the axle)through the wheel axle slot.. the bar is then rested between two sets of over lapping bearing at each end (which don't have seals and therefore lower friction) and added stick-on weights on the high point. The wheel bearings in the wheels has too much friction owing to the seals to do directly off the axles with any reliability. Too be honest it's not prefect as the wheel dia is so small it make it hard to do a perfect job but it does the trick in terms of a 90% outcome very quickly. Cheers Jack

Hi Garry, I started out with 33psi (as per my op manual) in the mains but running now at 28psi ... only have the 6ply on the nose and running at 28psi as well. Cheers Jack

Please tell me? … Hypothetically, if I was to pay (or cover their costs) for an RAA certificate holder to ferry my new ac from Bundaberg to Melbourne, would that be considered commercial? Cheers Jack

Great question Frank … surely there must be a high number of operations (see Major Millards suggestions) a suitably qualified RAA pilot could perform using a well equipped UL aircraft that would provide a low cost, safe and reliable alternative. This would have my vote for the RAA to scope up a discussion paper to include some limited commercial operations. Cheers Jack

Hi Chris Both my mate and I have fitted 10ply Trelleborgs to our 430 and 160 and are very happy with them. In terms of my 160, I needed to add a small spacer (3mm) on the outside axle mounting point to hold out the spat a little to ensure clearance. I bought them from M&C Tyres (talk to Adam) http://mctyresbendigo.com.au/specials.cgi for $88.00 each + tubes. Make sure you get 90 deg metal valve necks (not straight rubber as they won’t fit) tubes. I didn’t fit the 10ply to the nose wheel and left the 6ply in place as the clearance looked marginal. Fitting is fun (not) but suggest you get access to a tyre press … For what it’s worth, I did the following procedure: Break the rim seal on the side opposite the value … however you will only need to move this by about 5-10 mm as you run the risk of a tube pinch if you go too far. Unbolt the wheel hub (including brake disc) and then by hand spread the rims halves apart and fit a small bock of wood (10 or 12 mm is enough) between the two halves. (NB. The wheel has almost no taper or rim well to relief the pressure off the tyre bead so you need to create a gap by holding the rim apart with a small piece of wood). Then continue to press the tyre off the rim towards gap between the halves, but do this from the opposite side to the valve. Once you have the rim half out of the tyre, remove the tube. Turn the wheel over and place your block of wood to support the inside of the rim and then press the tyre off the rim. Fitting: Soap up the tyre bead and hand push in the valve side of the rim. Powder up the tube with talcum and slightly inflate and fit value neck and push tube into the tyre. (You only need a small amount of air in the tube to stop in getting between the two halves when you bolt up … too much air will make it impossible to push the halves together to get your bolts back in). Soap up the other half of the rim and push in and bolt up. (make sure you match the halves as per the disassembly and keep every thing is clean) Fully inflate and make sure you have an even bead line around the rim and it fully in place. Balance and refit to your aircraft. The only other issue to be aware of is the speed rating on the 10ply is lower than the 6 ply, whilst this isn’t stated on the tyre it is in the tech specs. However after talking this aspect over with a Trelleborg tyre expert he said that this would only really be a concern if one was running the tyre under load over a considerable distance and allowed to get hot. All in all I think the extra weight/benefit trade off is worth the confidence of reducing punchers in the field. What’s more, I think the side walls are so thick you would get away with a flat tyre landing without incident. Hope this helps? Cheers Jack

Rob, I would be worried too if your oil pres is dropping during flt towards the yellow.... clearly you need to top up before this happens. When I say I keep my oil level below the bottom mark, this is when the oil/engine is cold,..the level tends to go up a little when hot... so please be careful not to under fill either. If I was intending to fly for 4 hrs I would keep the level a little higher (at the bottom mark) and throttle back a tad and fly more in a cruise mode in climb etc .. the higher throttle settings tend to blow oil into the bottle a little more quickly. However I got to tell you, 4 hrs is a lot of flying for me these days and other needs (pit stops) often take the priority. Cheers Jack

Hi Rob, My 160 has a little over 300 hrs and I use about 50ml per hr as well. However I keep my oil level below the bottom mark when cold, which is recommended by Jab. I suggest you take a look at the "Service Bulletins" on the Jabiru web under "Dip Stick & Comaprisons"... this gives you details re oil levels. Cheers Jack

G’day Striker, May be stating the obvious, but have you check the Spruce catalogue for engine mounts? http://www.aircraftspruce.com/ Cheers Jack

I have a question on thermocouples for EGTs for my Jab 160? I’ve bought a VDO gauge and thermocouple from Jab, but I really don’t like to thermocouple as it seems big relative to the exhaust header diameter and it needs to be welded in place. Is it possible to substitute the thermocouple for the small probe type that is held in place with a hose clamp and still get same accuracy from the VDO guage? If so what “type” is this thermocouple … what do I need to ask for when purchasing? Any other ideas also welcome? Cheers Jack

Hi Wizard, E10 should be cheaper as it doesn’t attract the excise tax components as it does on unbelnded fuels; although your fuel consumption will go up… it’s your call if you use ethanol in your car, albeit I wouldn’t use a drop in any of my toys. You will find that all of the major oil companies (independents should too) will label at the pump if the fuel contains ethanol. However don’t be lulled into believing it’s ok for your ac because you haven’t had a problem in your car … it is not technically suitable for aircraft engines and it WILL expose you to potential fatal consequences. Cheers Jack

G'day Wizzard, I think ethanol in Avgas is a long way off (if ever) as it not considered a viable replacement on technical grounds, nor is there likely to be global agreement around a standard spec. Mogas is a different story … E10 in 91 ULP is becoming more prevalent in some states (NSW) and less so in other states. The jury is still out as there just simply not enough of the stuff to blend off into 91ULP and meet 100% of the consumption. Performance Mogas, > 95 Ron, is less likely to be affected with ethanol blends….. In the main the major oil companies have resisted ethanol blends as it undermines the product positioning of better fuel economy, cleaner combustion etc. To answer your question, ethanol plays havoc with plastics (including fibre glass) by softening the materials, it is hydroscopic and absorbs water from air, you have to burn twice as much to get the same energy value and it leaves carbonised deposits owing to poorer combustion. Lastly is has a very high latent heat of evaporation and acts a bit like a refrigerant gas which will chill the induction air and potentially increase carb icing problems. Bottom line ... never use any ethanol fuels in an aircraft. Cheers Jack

Hi Watto, Not sure about where (aircraft, car, motocycle ???) you got a fuel leak when you used BP Ultimate …. May I offer you a possible answer as to why? In the main, BP Ultimate is lower in aromatics than the Shell and Caltex perfomance fuels, which can cause seals/O rings to shrink and leak, particularly if you have been using higher aromatic fuels and make an abrupt switch. In some instances, you need to manage the switch more slowly to allow seals to adjust to the change in aromatics content…. The fuel companies do this all the time and blend up or down the aromatic content to minimise fuel leaks, particularly with diesel fuels. However in support of lower aromatic fuels (BP Ultimate), these are much more compatible with avgas (which have even lower aromatics) and burn cleaner than higher aromatic fuels. A simple test is to run both fuels (BP/Shell) separately and you will see a high soot deposit in your exhaust pipe from the higher aromatics fuels (Vpower) as they don’t burn as cleanly. Personally I prefer Ultimate as its high octane (98/99 RON) is an outcome of a better refinery process and not from boosting octane with cheaper, poorer burning, hydrocarbons. Of course you use what best suits your needs, but hope this helps? Cheers Jack

In terms of the Rotax engine oil recommendation… the factory spec is somewhat basic and calls for quite an old lubricant design, which the majority of 4 stroke, wet clutch, motorcycle oils will meet… although I suggest you stick with what is supported by Rotax to be sure. Looking at the AeroShell Sport Plus 4, it’s not hard to see this lubricant easily exceeds Rotax’s minimum requirements. Whilst the product seems to have the same spec as the Shell VSX 10w-40 it does have a higher claimed API “SL” specification (compared to VSX “SG” spec) which should mean better anti-wear and soot handling characteristic. Additionally it also has the Japanese JASO MA spec which means it’s not friction modified. Personally I wouldn’t hesitate to use the AeroShell Sport Plus 4 lubricants based on it technical profile and the audit process behind the Product Release Note. Hope this helps Cheers Jack

Attached below is a a part qoute from from the press realese re Rod Stiff being awarded the August Raspet Momorial Award at Oshkosh last month. Not sure if anyone in the forum knows the details, but clearly Jabiru are building a range of new props? If you are considering a new prop, it might be worth your while to contact Jabiru and find out about these new developments? "The Jabiru product range includes Jabiru factory manufactured aircraft, experimental kits, and aircraft engines. A range of propellers, designed to complement Jabiru engines, is being developed." (Rod Stiff) Cheers Jack

Good point Qwerty … you’re correct, but it does depend… hope that clears things up for you J? Jack

I’ve read the published Technical Data Sheets for Shell, Caltex and BP … whilst both Shell (V power 98) and Caltex (Vortex 95 & 98) make no statement, that I can see about ethanol, it looks as though neither of these fuels has any ethanol, albeit implied and interpreted by reviewing the various specs/formulation published. On the other hand, BP Ultimate 98 clearly states it doesn’t contain any ethanol, which in my opinion, is supported by its Technical Data Sheet and published formulation. If you want to test for ethanol, simply fill a glass jar with 50ml of tap water and make a line on the jar with a marking pen or a bit of tape… then fill the jar (taller the jar the better) with an additional 200ml of fuel and the shake it up vigorously, and then some more … if the water looks like it has increased, (as water and ethanol have almost the same specific gravity) you have found ethanol…. Don’t use it! At the end of the day, don’t take my word for it, do your own research and check with the engine and fuel manufactures. Cheers Jack

G’day Ultralights In my view it would be almost certain that your source of pre-ignition has been caused from a carbon or lead deposit. If anything, BP Ultimate has a very effective additive pack which cleans up deposits, which may have triggered the pre-ignition, albeit I think this is remote. The residual deposit would have been in all likelihood from poor combustion processes, which may have come from the current or previous fuels used … I wouldn’t expect the 98 to be the problem. BP Ultimate is actually and typically 99+ RON, as the minimum standard is 98 RON … the oil companies always try to over shoot the marketing specification to ensure they don’t fall below the minimum performance claim and leave themselves open to challenge. The other interesting fact about blends of Avgas and ULP - MOGAS is the synergistic effect that the lead in Avgas has on the over all Octane rating. Paradoxically, blending is not linear in terms of octane ratios but synergic +ive in boosting the octane of ULP. Therefore you will always find both the MON and RON north of the linear ratio equation when blended… this could be a useful fact if you have to mix the two products. Having said this, always follow the engine builder’s recommendations as they have spent the R&D time around these issues. Cheers Jack

Hi Yenn, I agree with you … I really can’t see any of these engine mods doing much to reduce bore glazing. In my old motorcycle days there were inlet or exhaust restrictors fitted to engines to detune them for children to ride them with less power. Be it a 4 stroke or 2 stroke engines they all had deposits problems along a high propensity to suffer with bore glazing. Apart from your suggestions to use full throttle and steep climb out, I think a chat with Rod Stiff a good idea as well. Regards Jack

It’s not so much the engine speed (RPM) that causes bore glazing, it's the load …. The engine needs to be loaded up and run at the correct engine temps. Light loads and low temps will cause glazing, high oil consumption and short engine life. Full power at take-off and 75% + at cruise is the way to go.... not sure how you do this as it sounds like you have more grunt than you need. Regards Jack

Hi Moroa, Attached is a link on VGs. http://www.recreationalflying.com/forum/general-discussion/4403-vortex-generators.html I tried them on my 160 and was disapointed with the outcome and removed them.... take a look at the link for more details and comments. Regards Jack

Hi Modest, Your pic in your profile is too small … love to see your spats more clearly, can you try and post a larger picture? One of the things I tried was to fit a small trim tab to the back of my front spat, although, like you, it only really worked at one power setting, which I set up at cruise. After I took the front spat off and fitted the hub cap the ac became coordinated at all power settings. Cheers Jack

Hi Rob, I have played around with various combinations of spats/wheel covers and found that you may lose 1 or 2 knots if remove the spats. Interestingly I found my front spat worked in some conditions like a servo on my rudder and wouldn’t allow the ac to bank and remain in coordination as well as it would without the spat … I was working the rudder all the time and once I removed my front spat it made my 160 much nicer to fly as it remained in coordination without me having to tap dance on the pedals. The other combination I have tried was to buy a set of wheel covers from the UK (Instrument panels) which seemed to give me the same speed as the spats and where fantastic for dirt strips and a little lighter too. Currently I have settled on a wheel cover on the front and the Jab spats fitted on the mains when on my home strip (Tyabb) …. I fit the wheel covers if I’m doing dirt strips. Hope this helps? Cheers Jack

I saw this other day ... it's a video from the EAA on how to do minor repairs on wooden props. http://eaa569.org/videos/propeller.html Cheers Jack

I have been running my engine on BP Ultimate 98, which is nearly always blended with some Avgas top up…. I have been doing this now for 250 hrs and my engine runs as sweet as a nut. No vapour lock, no detonation, plugs look spot on, all temps in range, oil analysis normal and no discernable power change…. No problems. Cheers Jack

G'day Theo, Its a 2 blade Revolution ... they are made up in Bundaberg. It works very well in terms of performance but made the 160 feel like it had a turbine up front. I also know a couple of guys that have the 3 blade prop on the 6 cylinder Jabs and they say the same. Cheers Jack