Vev

Hi Yenn, Sorry to hear you are having engine troubles but glad you had found the problem on the ground and not in the air. Was there any burnt oil (black) around the rings lands and groves as well as the underside of the piston? Btw ... There was a change in piston ring grove clearance on later pistons that mostly fixed the sticky ring problem, although if your engine is over heating ring grove clearance wont help much. Without seeing your piston crown, it does sound like a lead deposit from avgas ... however I have seen all sorts of deposits from oil getting by the rings and down the valve guides when Jab engines are on their last legs. I'm interested to know how hard to you run your engine in cruise? I have found that the Jab engine works best when used hard with the current jet recommendation ... the extra fuel really keeps things cool and the engine loves it. Cheers Vev

Hi Yen, They are just commodore rings ... made by Hastings if I recall. May be best to just order them directly from Jab, I think the last set I bought were $100.00 for a set of 4. You may find your barrels need a hone and might be glazed if you think oil is getting past the rings. Cheers Vev

Hi Win, I took a look (didn't get to fly) at this aircraft at Natfly and they did look quite good.... The only criticism I had was the seating position felt too flat and had a bit of a hump where your legs rested... not a big deal and some may even prefer this seating position. The finish looked very good and quality of the materials and fitting was consistent with what we have become use to these day. It has been designed more for the airport to airport use with an over night bag and not set up for outback or bush landings. It seemed to be great value for money ... but a 30 min fly around the local patch would be good to see if it lives up to its looks. Cheers Vev

The pilot is expected to make a good recovery, notwithstanding he has a few broken bones and he's very sore and sorry ... I can't say the same for his trike and wouldn't expect it to be flying anytime soon if ever again. The good thing is he's still with us and we are all very thankful for that. Cheers Vev

Hi Martin, Your alternator is an 18amp job and should be showing a positive charge well before 2000 rpm. Apart from checking all of the connections, including the earths etc etc. The voltage reg/rectifier is a little underdone and can be replaced with a better unit .... However it sounds more like your alternator is on its way out or already gone west. Take a look at the stator windings through the back of the stator holder inside the rotor and see if the windings look black or at least very dark brown. If they are black its a good bet you have lost a pole winding or two. Unlike almost all motorcycle stators, the stator body is insulated which doesn't allow one to do the normal short circuit tests (finding continuity to the stator body from the output wires), which means you need to take a look at it and see if its had a melt down. I have seen one or two windings on the poles fused together after burning out and still showing some charge albeit marginal. Hope this helps. Cheers Vev

Hi Don, I've had an MRX in my jab for a couple of years now .... it works fine in terms of alerting me to a nearby ac. As for direction .... I look out the window and look for it. Cheers Vev

G'day Turbo, Yes got that, but Peter also asked about the 2200 engine.... which is what I was mainly answering. Nevertheless, I thought the fuse was the same length as the 160 and the horizontal tail and elevator was bigger (not smaller) and the rudder and vertical tail was the same as the 160 (although a new larger tail/rudder is going into production to replace the retro ventricle fin). Wings are longer by 1.5m ... not a bad thing in warmer climates such as Brisbane where Peter lives. In any case, I still think they are great aircraft and hard to beat, notwithstanding there's always room for improvement with any machine. Cheers Vev

Hi Peter, I have a 160 and have done 450 hrs in Jabs and I think they are great. They are strong, easy to work on, cost effective and have great local factory back up. Cheers Vev

done ... good luck Motz Cheers Vev

Thanks D10, I agree with Nev too ... hard to find a hole in any of his posts. Clearly the whole thing is a can of worms, it makes the mind boggle .... I think I shall pass on this invitation to participate in the fly-pass. Cheers Vev

Guys, Many thanks for the input (particularly TP). Basically there is a couple of us have been asked to do a demonstration fly past and I'm concerned about what is considered formation flying even with more than 100ft of separation ... the CAR 163/AA isn't clear enough to say any distance is enough not to be in formation. I read, just the mere fact that you are travelling at the same time in the same direction a mile apart could mean you are in formation and braking the law if you are not endorsed to do so. What's more, the RAA manual doesn't take into account that a mixture of GA and RAA aircraft could formate together either, even if one had a formation endo. I think CSAS have recognised that there is a gap in the CAR and Part 91 is going to be their opportunity to fix things. As for now ... I am very confused about what's ok? Cheers Vev

I am well aware that one has to have a formation endo to fly in formation, but how close can one or more ac fly in close company before it's considered formation flying? I use to think it was no closer than 100m but I'm not sure that covers all the legal limitations. I have read CAR 163 and 163AA but I'm still not clear on it's meanings. Interested to hear any views? Cheers Vev

If you had of watched it you would have known that the washer face is part of an AN bolt head ..... as for the ending, it was nuts and a bit screwed up.

I found this interesting video on AN bolts. http://www.eaavideo.org/video.aspx?v=672278271001 Cheers Vev

Hi Russ, I presume you are asking about 4 stroke engine lubricants. This is a very complicated subject and one that could take a lot to explain .... I will try and keep it short and sweet, so forgive me if I just skim the surface. The different base stock of oils have pros and cons ... Group 1 mineral base oils are cost effective, have higher aromatic qualities and tend to absorb contaminates and clean through better solvency. Hydrocracks base oils have slightly lower solvency than basic mineral oils but are more stable and have a lower resistance to oxidation from thermal stress. Synthetics are more stable to oxidation but have a lower capacity to absorb and dissolve contaminates, they are quite expensive compared to ordinary mineral base oils. Some lubricant manufactures try to find the sweet spot by blending mineral base oils and hydrocracks to get both the solvency and stability as well as a lower costs ... I think this isn't a bad approach overall. Some go all the way and use 100% PAO (Polyalphaolefins), which I think is more about marketing than a technical requirement, although I know some will argue differently. One needs to think of the base oil as the carrier for the additive pack ... the additive pack is the real performance improver and has the biggest over all impact on how well an oil lubricates and protects an engine from wear and corrosion. No matter what approved lubricant you use, you can't beat a higher frequency oil change .... by doing this you stay ahead of oxidisation, additive depletion and get rid of the abrasive and oxidisations causing contaminates. Oil and filters are cheap ... I say change them often. Cheers Vev

Hi Russ, Decalin does scavenge lead for the combustion chamber and works ok, but it doesn't remove lead from the fuel ... the white is usually a formation of lead phosphate from additisation of Decalin (decahydronaghthalene) as apposed to lead oxides from the normal lead build up we see in the combustion chambers. Be mindful you will still get lead oxide combustion contamination into your engine lube and will still impact on oil change frequencies in Rotax engine and other engines for that matter. (I'm sure Nev will give better guidance on engine service frequencies re combustion contaminates). However before you add this to your fuel I would check with the oil company and ask them for their view and make sure there is no compatibility issues. Cheers Vev

Hi Alan, It is highly possible your fuel may not have gone stale over that time frame if all of the conditions were ideal. However there are factors that could change things quickly and you could end up with a very different outcome. Long before you end up with a sticky goo, you will get a degradation of octane which will cause detonation ... this detonation will cause a huge amount of damage that is irreversible and could lead to catastrophic engine failure. Personally I would rather play things safe and use fresh fuel and only store for a short period and blend your 2 stroke oil the day you use it ... why risk damage to your pride and joy as well as your own and pax wellbeing. There's a very old saying ... there's no fuel like new fuel and old fuel is like no fuel. Cheers Vev

Hi Russ, Good question.... I'm not a fan of adding anything to fuels to boost octane as there are too many uncontrolled and unknown elements to manage. Not sure why you want to bump octane? Although there is an alternative, you can blend Avgas into Mogas to boost Mogas octane, there is no unknown compatibility issues with this approach. The octane bump is greater than the normal linear blend ratios as the lead in the avgas has a synergistic effect on the octane in mogas. Additionally, avgas will also reduce the volatility and slow down evaporation and improve vapour lock issues. However there is a down side, you will get lead some deposition in the combustion chamber and you may have an increased oil change frequencies. Cheers Vev

Hi Neil, Temperature and the quality of the seal on the container will have an effect on how long you can store fuel. If you store your fuel in a well sealed container and keep it in a cool place, which shouldn't be hard at Hoppers Crossing this time of year, it will be fine for a 2/3 months without issue... 1 month less for summer. Fuel can degrade over time owing to two main factors (there are others but less of an issue), firstly the light fractions in the fuel evaporate if exposed to the atmosphere where you will end up being left with the heavier components and lower octane.... Secondly is oxidation, often stated by heat stress, where the fuel basically breaks down and runs away into auto decomposition. If you keep your fuel in a cool place in a sealed container you get around 95% of the issues that destroys octane values. However at the end of the day, "it is always best to use fresh". Cheers Vev

I have built a 18m x 28m Hangar in the last 12 months and Safety Steel in Dandenong got the job. PM me if you want full contact details and price guide Cheers Vev

Almost but not quite ... I think it easiest to explain if you read the Jab's Advisory Notice, which explains in detail the cause and the fix. JSB031-1 Jabiru Engine Through Bolts & JSD031-1 Service Directive Cheers Vev