jetboy

There is also a new maintenance manual now requiring 25 hrs oil & filter change interval. A bit of intelligent and reasoned explanation for this would have been expected, sadly nothing forthcoming. I know the hydraulic lifters are more fussy with oil, what has that got to do with the solid lifters? I know some prefer to throw out the filters more often than normal, but what is the new guidance for filter inspection limits? I see very little debris @ 50 hrs, so cutting them @ 25 is not going to be a reliable indicator, the sample period is too small. PS Rod doesnt think we are all idiots, he knows it because we kept on buying those engines......... No sign of the rumoured Nikasil cylinders yet - should I wait for them? Ralph

The 701s are purpose made with wet wings etc. specifically for the requirements of the JFS100 and I think from reading the small amount of technical info he has a good supply of engines and the expertise to keep them running. That said the JFS100 is only 90 shp peak and supposed to run in naked form for max. 5 minutes. Here is an informative article on a KR2 install, be interested to know if its still flying in Australia? http://www.n56ml.com/strent.html fuel flow is likely 45 L/hr in cruise wheres the same performance without satisfying noise can be had with piston engines for 15 L/hr. To use the JFS100 in my 701 I need a serious increase in fuel - 2x 60 litre drop tanks ? and more for background info, my experiments are logged here Ralph

Lyle, You mention specific need for electronic; that would be relatively easy to do Differential pressure transducers are found in a lot of things these days. The voltages are small so they need precision balanced amplifiers for the signal, then feed it to a bargraph IC to drive the indicators or alarms. But I would visit carefully what you are trying to achieve; as the LRI does not appear to be very useful if you have flaps or differing loads to calibrate for. Cessna style stall warnings are much more useful in my opinion. Because theyre mounted in the wing it appears they accurately indicate the attitude when the air starts peeling out in the bad direction and flight is about to be interrupted. I like the flap/switch type of the early models - reminiscent of a heart monitor - irregular chirps= caution, flatline tone=flight terminated The later reed type systems give more gentle and progressive alarm, but sound like strangling the turkey if youre having a difficult day. I never did get used to that. As the turkeys get older, they squark less too. Ralph

They already make certified and non-certified engines. you just pay more for the cert. one. The difference between a certified engine is that one of them has managed a 50 hr endurance test. The spec is JAR 22-H (EASA CS-22) and also ASTM F2339-04 for some engines This is also the spec for the Rotax 912A The 912S and -F comply with the real aircraft certification FAR-33 This requires an engine to go a whopping 150 hours without failure, if that makes you feel better. The way Jabiru continually fettle their production engines whilst claiming they are still certified is beyond belief. But given the standards met, it doesnt really matter. Ralph

Jabiru can't arrange good enough throughbolts to hold a diesel together. Dieselten, Facthunter, Maj, all right on and I'd love to find a suitable kero burning engine - have been following every type mentioned plus all the rotaries that have claimed multifuel development and all turned to cinders before a single unit got sold. A 3 cyl. 2-stroke would suit me best. Just yesterday I was studying here http://www.enginehistory.org/engines.shtml the Juno history particuarly interesting Ideally Jabiru might fix all the issues but we have to wait a couple more years because the current mods have not worked yet. I can understand why there would be no reason (for them) to make an option to use the 912 or UL260 if it's any good. Their decision to build their own engine when forced to and reasons for not using the 912 is well documented in their history. The option to fit a better engine and do your own approvals is still open. Presumably those fitting the Rotec liquid heads or the SA fuel injection will already be obliged to get the same approvals for these, as I don't see any sign of Jabiru doing it for anybody. Like everybody, I keep looking for a better alternative - the truth is nothing exists so in the meantime I hope my aged 2200 without the "improvements" can hold out till a replacement is available. Keep the discussion up- we may get there (perhaps needs shifting to another thread, but talking diesel and having a sturdy crankcase and cylinder attachment is still relevant here) Ralph

One issue I will re-state is that the float needle valve rubber tip deteriorates with time. It will often fail during extended park-up and the fault is not even visible looking at it. On engines with fuel pump this causes serious over-rich running. On gravity feed installations like mine it shows up as minor fuel seepage out of the carb if fuel is not turned off in the hangar. I found this out when my plane would only cold start without "choke" actually it was starting better than ever in this condition. Float level did not change, and EGT are normal. Ralph

http://www.kiwiflyer.co.nz/KiwiFlyer-Issue-14-ZK-Review-OctNov2010.pdf the print is hard to read but I've seen this "Wild Thing" and it doesnt look any different to the Rebel. Ralph

Bing carbs dont have a choke so if you find the engine running better with that selected - it will allow more air after the starting fuel has drained - then your'e running too rich without the "choke" selected. More likely causes are too much fuel pressure, faulty float needle, faulty float chamber venting. Ralph

My original manual from 2003 states 30 ft-lbs for the thru bolts. Maybe you are mixing with NM? Ralph

Yes use a 10 K resistor to pin J. It may be OK without the capacitor, depending on the particular phone. The resistor is to reduce the high level of audio that will overload most phones without Ralph

Distributor lead ends have a habbit of working out of the sockets if they have been inserted recently Rotors can get loose and wobbly if the glue is not right Plug terminals can unscrew and be loose According to Jabiru, set plugs to minimum gap (.020 I think) Not what they come with in the box Let us know what type of coils you use Also any conclusions re the mixture (I expect its only idle mix thats rich) Mine has developed rich mixture at startup, not been able to find the cause, float level correct and I have no fuel pumps to cause it. Ralph

from 2004 - 2010= 30500-ZF5-003 its been reported that the coils are now fitted 30500-Z1C-023 Ralph

Stuck valves can allow this to happen. Really bad case the pushrod becomes jammed beside the rocker. Sorry I dont know the recommended fix, just observed this happened to an engine that had been extensively overhauled at the factory a year prior, and it took 1 LAME workshop fix, 1 motorcycle workshop fix, 1 fix by the owner to reach a reliable outcome. I think it involved cleaning the valvestems and reaming the guides. Ralph

Thanks Maj, Yesterday I replaced all the Gates fuel hose with Dayco made in USA SAE30R7 hose which the local supplier had to get in for me. Whilst none of the Gates hoses have ever leaked, all were cracked and hardened, although this was never obvious except at the ends. When flexed, there are both radial and lengthwise cracks of the outer exposing the weave. At the ends the cracks go right to the centre in straight lines. The kit is a Zenair 701 supplied from CZAW and as far as I can tell the small amount of hose that came with it was same spec. I will do some more research but Aeroquip and ACS do not appear to supply this type of hose. As for the Cessna which I operated for 12 years, I never did any work on it that was the domain of the LAMEs, just that I noticed from the logbooks that none of the wing root hoses nor the one to the carb had been looked at and I asked about this (knowing full well I'd be up for at least $500 too) .... but the response was .... they are fine, nothing should be changed. But what i'm quoting was 10 years ago and anyone that still has a small fortune to run a Cessna round here must have started their aviation exploits with a large fortune because everything now must be replaced by the mntce manual dates so I think its seatbelts, hoses every 5 years (and landing light switches) I sold the Cessna so I could build the 701. I'd really like to hear what people are using or not using for their replacements on microlights. Gates does not cut it anymore for me, whether it be cars, JetA or Avgas, its cracked everywhere, and hardens in as little as 6 months Ralph

Checked today - cost of Gates USA FI hose $45 per metre BNT supply DAYCO brand USA the regular 30R7 type $ 5 per Foot or 30R9 FI $23 per Foot Supercheap is $10 per meter for 30R6 spec

Is there a quality brand rubber hose for fuel available? My 5 yrs Jabiru is almost outlasting the fuel lines installation, but they are cracking around the end flares as they go over the fittings. Yes I'm aware that 2 or 5 years is the 'life' especially in FAR23 aircraft but my Cessna was near 40 yrs old and unlikely to have had any replaced, I asked about doing it and it wasn't considered a good idea. The most common 'quality' hose available here is Gates, however this is the hose I'm having the cracks appear, they go straight into the inner. It is fuel & PCV hose SAE 30R7. Repco can offer some gates SAE 30R9 'fuel injection hose' and while it looks OK new the same can be said for the stuff i'm replacing. Supercheap carry some other brand, which I'll look at tomorrow. I'm really a bit annoyed the Gates, which doesnt like JetA that much either, just doesn't work well with er... fuels. The hose ends out of the fuel tanks came from Europe and is still as flexible and intact as new. Ralph

Hi Greg, I cant see anything bad in the photos in fact the heads look much cleaner than mine @ 300 hrs I think the machined ridges are still showing in your head - cylinder contact area these will become flat in the area around the bolts anytime cylinders are checked above 20 ft-lbs too often. When you put it back be sure to have the clearance honed out to the latest specs, and the cylinder base nuts bevelled per AVDAL SR050 if not already. The workshop in UK also recommends heating the cylinders around the bases before tightening them down to make sure they don't set oval too. Wish I'd known about that before putting mine back. But I did get + 200 rpm extra in the climb from the fixed base nuts, so it has been worthwhile. Ralph

The A200 is directly compatible with the Bendix King KY97, which I have connected a cellphone plug to. For the cell mic connection run a 10K resistor via 0.1 uF capacitor to pin J, the pilot mic connection on the radio. Capacitor probably not essential but at your risk without. For the cell spkr to your headsets run that to pin C, D, or 3, the aux audio into the radio. For other misc gadgets they can use one of the aux audio inputs: C, D or 3 Ralph

Its not a vibration problem range just an advisory to not run at too light a loading as the engine is not suitable to operate for long periods at low power settings - cylinder to piston rings seal suffers etc. Both NZCAA documentation and Jabiru comment state the bolt issue is related to loose prop or propstrike damage, and the original ADs and SBs issued were two items to be treated at the same time: prop attachment and flywheel bolt repetitive inspections. Two years ago Jabiru substantially changed all the parts in the flywheel stack - except the gear wheel - this latest failure appears to have happened with the new assembly. We are waiting to see how this new development pans out as its an ASTM certified engine and the problem happened to an LSA, operating under the ASTM continued airworthiness system. The rest of us, with the older engines, have mostly used the results of the BMAA and RAANZ investigations, there seems to be less problems occuring with these, and the thru bolts have come into more attention than troubles with the replaced flywheel capscrews. Ralph

They did act swiftly and I have no problem with compliance (doesnt take much more work to replace the capscrews when doing the required checks anyway) However some complications do arise: 1/ the subject aircraft a J230 was new this year I understand, and operated as certified aircraft rules ie. LAME mtce schedule with all the enhancements that provides.....and the engine a certified ASTM compliant version with all the extra care and attention that attracts...with the continued airworthiness instructions provided by the manufacturer....so I'm waiting to hear of a SB from said outfit 2/ the subject 3300 presumably had the most recent flywheel attachment system - substantially changed pre- July 2008 (Jaba chat refers) which really means the old attachment itself was OK - just the original set - torques have been altered - but still not up to the torque specified by the bolt manufacturer and our RAANZ advice which as a microlight operator I can follow. this is the same advice being used in UK and Europe. 3/ I'm not trying to critique or re-engineer the problem, but its not technically really a flywheel, just an aluminium disc for mounting the starter ringgear on and a few magnets. The only failure that results in "uncommanded engine shutdown" is the ignition, which could be eliminated by changing to dual electronic or mags, thus also eliminating the distributors and their drivegears, a reliability risk area in themselves. I'll shutup for now just needed to vent some. I suspect my engine will wear out in other areas before I need to replace those capscrews more than once Ralph

saw it at Oshkosh one year, only on display, along with the facetmobile. a bit similar to the ligeti Ligeti Stratos

Perhaps you should call Max and discuss the reasons for the Ulpower groundings and what is available with the Bantams. I have owned two B22, the last one just prior to the B22S modification and an owner nearby has a B22J. I know they fit the 3300 to the SA versions but I'm fairly sure the NZCAA rules would not allow any more weights than whats currently on offer a microlight is just that - anything modified has to be drop tested and structural limits checked remember the sheet of paper started with an empty weight 148.5Kg before the rules changed to MTOW ratings, but if your market isnt fussy about design rules then you can use a 350 chevy if U want just wear steel capped shoes its might scary when the prop arc goes thru the pod where your feet are (dont ask) Ralph

Ulpower issued a SB 3 wks ago about ECU connections corroding, whether this has anything to do with the 3 Bantams currently inoperative and the other one's electrical failures I havent heard. Otherwise its been a good engine in NZ so far. Ralph

Not to say they are a gimmick but thats the only category you left for me to apply; In summary, and having used one, I cannot think of an RaAus type plane suitable to use them on, especially STOL style with slats/VGs. The reasons I guess for ineffectiveness: No indication compensation for different weights carried No indication compensation for amount of flap deployed In the context of the type of planes we fly, I think it does not adequately address the relationships of low inertia vs. airspeed and power settings, in gusty conditions where outcomes change quickly. Dont be put off by my opinion, it costs so little to try one the plans are readily on the net and the indicator gauge is an off the shelf HVAC device, and calibration is easy to do. Ralph

I tried one, useless in CH701, Easy to build but just not meaningful enough (things unravel fast in a 701, no time to watch what the clocks are doing) I could install it again but it is a waste of panel space Ralph seeing your poll has got ages to run I reserve my decision