Alan

Thanks all, Seems good velcro is the way to go. Regards Alan

I have an SE2 in my J230 and currently use the suction mount to fix it to the lower right hand corner of the wind screen. This has become loose several times and no doubt is not the best position or orientation for reception/transmission. What have other J230 owners done to mount their SE2s? Regards Alan

Problem solved. My 12 channel MGL temperature monitor had been fitted incorrectly and was connected to the aircraft earth. The instructions clearly state the instrument should be earthed on the engine block. After correcting this my CHT temperatures all remain below 150°C and agree with the Jabiru original sensor fitted under #6 sparkplug. Finding this earlier could have saved me a lot of stuffing about with ducts and engine cowl flaps, to say nothing of an early complete engine re-build by Jabiru taking it to the latest Gen 3 spec ( After fitting the CHT monitoring I thought I had been over-heating my engine continuously - hence my caution). If you want something doing correctly - do it yourself comes to mind. Alan

I have 12 channel temperature monitoring on my Jab 230C with the sensors fitted between the spark plugs on the heads. I was wondering whether there is any known calibration differences between these and the original Jabiru sensor ring fitted under a spark plug. On a hot day during climb out my between head CHT indication can rise up to 180°C, (although in reality I slow the climb to keep the temps down, max last flight was ambient 35°C, CHT =178°C). However, the original Jabiru spark plug senor is always well in the green? Alan

Thanks for all the comments. The electric pump was used to bring the fuel up to pressure as the Jabiru 230 POH at start up Then switched off for the start, taxi and run up to verify the mechanical pump. The electric pump is switched back on for the take off run and switched off once safe height is achieved. The electric pump in a Jab 230 is in the back next to the header tank. All the fuel lines forward of the bulkhead have fireproof sleeves as factory fitted. This is the first time I have had a Jabiru motor grumble in 14 years. No problems in the 5 hours since. I am more or less convinced this was my fault, with me tolerating a long idle having to wait for the student aircraft caused the fuel to vaporise. - what fooled me was a normal run up check and the initial take off run at WOT was fine.

I had no idea how long the student would themselves be idling at the threshold while being instructed, they knew I was there when they first left the runway (airmanship?); had i known how long I would have shut down . Idle was low enough not to require brakes. I was paying - my plane. I must admit I was not aware of additional sooting of plugs on mogas; not heard of this before. Plugs were all perfect when I checked afterwards, but that does not mean much after further running. No the jab is standard and has no fuel return line.

Jab 230. Engine Gen 3 with all latest mods (18 hours since overhaul). Running on BP95 Auto Gas (Avgas is now too hard to get) . CHTs pretty even and don't exceed 170°C. No previous problems experienced. Until a few days ago - Air temp 35°C, all checks normal, put out taxing call and held short of runway while student in 150 landed who then came in off the runway onto the taxiway and turned back towards the runway in front of me. Then I waited and waited while monitoring CHTs. Eventually the instructor got out, gave me a wave then leaned in to the door for further chat. OK so a student doing a solo. What this meant was I was idling for about 15 to 20 mins total, but the CHTs all looked OK. The student cleared and I back tracked and took off. Just after rotation (app. 150-200ft) my engine started running really roughly, revs dropping and loosing height. I was preparing for a cane field arrival when sufficient power came back to hold altitude, not too turn back, but I had more options. After gaining circuit height I prepared for a normal landing, but with a now normal engine behaviour, I gained further height but remained local within gliding distance of the airport. Plugs, leads, filters checked. Fuel checked for water and any solid residues after evaporation and then donated to the lawnmower. The engine has behaved normally for about 5 flying hours since. Lesson learned, I was not far from flattening the sugar cane. I believe the rough running was a vapour lock caused by the long waiting time and high ambient. I had the electric fuel pump selected and could hear it running. However, I was thinking it would be pretty simple to set up a temperature monitoring of the firewall forward fuel lines, possibly on the inlet to the mechanical pump or inlet of the carb, but what temperatures would be regarded as critical? I'll take some of the fuel into the lab and look at its boiling point but that would not test actual vapour pressure nor allow for the 4psi of the fuel system. Any thoughts out there?

I have some plotter rolls (contnuous graph paper roll about 300mm wide) in the lab drawers from some spectrometers we replaced in the 80s ( I hate throwing stuff out). They have a clear grid marking, but from memory the X axis is marked in wavelength units. They are possibly 50m long. I'll check details when I get back to work Tuesday. Or PM me an address and Ill send you a roll to try. Regards Alan

Up until now I have always used Odyssey Batteries in my J230. However, I have just found my local battery shop is quoting a 2 months supply delay, so I went looking at alternative lead/acid batteries. Now the Odyssey battery is quoted as 200CCA, some of the batteries I have come across advertise 300CCA. Given the starter ring is at the back of the motor and the flywheel (prop) is at the front, should I be concerned for the starter ring attachment, crank shaft, etc as a result of the extra torque? Alan

That may not be a silly question. But are window films polarised? and then again are there variation in the line resolution of the polarizing and does this matter?. But thank you a good point; It has promted me to think, I have several redundant LCDs, I'll strip the polarising layer off these and test various films

My Dynon 10 A has been in service since 2006, so I can't really complain. However, the LCD screen has slowly deteriorated to a point requiring investigation. The polarizing layer on the LCD has started to fail via delamination. The instrument is still clearly readable, but this deterioration is no doubt on going. This is not a uncommon LCD failure mode, no doubt promoted by a hot hangar environment. Sending this back to Dynon USA for repair may take several months under current freight restrictions and I have not even enquired about the cost of this. It has been reinstalled to fill the hole in the Jab panel. The Dynon 10A LCD panel is easily accessed as I have already been inside to see if the LCD panel had any ID for sourcing a replacement. What serial numbers I found, Mr Google, Alibaba etc did not recognise. So eventually I am obviously going to have to replace the polarizing layer (plenty of demos on youtube) or bite the bullet and send it back to Dynon. But my question is, does anybody know of a source of LCD polarizing layer material? I get plenty of response to a internet search, but these all seem to be screen protectors for phones, tablets etc. and I am not sure these are polarized. Ill buy one and test it. Alan

Out of curiosity and because I had access to the tools when I first got my Jabiru I did some oil analysis work. ( I agree it is of very little value in comparison with the filter cut). In addition to routine spectro oil analysis, I used Ferrography (extraction and classification of wear particles up to about 150µm) to look at the oil during running in [i can probably dig out the photographs of the wear particles from the lab archives if any body is interested]. By heat treating (330°C for 90 sec) the particles once deposited on the glass slides, it is possible to differentiate the high grade alloys from mild steel and cast iron. When looking at oil from a reciprocating engines either diesel or petrol it is suprising how little of the ferrous wear product comes from the cyclinder material. We also collected vibration spectra from several Jab 230 3300s as one of them had an unusual vibration. Other than variations in frequency amplitudes they all had very similar spectra - surprise! The rouge vibration turned out to a be a front wheel spiining up during flight - a flap on the wheel spat fixed that. Regards Alan

Probably been dicussed before, if so sorry. Does laser/plasma cutting of alloy sheet leave any residual stress due to the heat gradient, especially with regard to pre-drilling for the rivet holes? Regards Alan

My 296 screen faded out and I was unable to source a replacement screen or repair service. So I replaced it with a Aera 660. Visually it is brilliant, has all the whistles and knobs you could wish for as a package and it was easy to mod the 296 mount to take the 660. However, because I used Ozrunways a lot during the fade out, it has become my secondary device and sits most of the time just showing the synthetic 3D vision window. So far I have not found out how to upload plans from a PC to the 660, nor can I download recorded tracks like I used to with the 296. So still a lot to learn. (Any hints here would be gratefully accepted to save me ploughing through the manual again.) Ironically, just after I had committed to the 660 (not cheap), I found a replacement screen for the 296. It was an easy repair and now functions perfectly with a bright screen. I am tempted to put it back into service as I know its functions so well. Next to be fixed is my Dynon 10A. The display screen is bright enough but the clear window (antiglare plastic) has developed a rough surface. It does not effect functionality but looks poor. Alan

Interesting. I can find no mention of a mandatory L1 practical course on the RAA website. Regards Alan