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Another Jab bites the dust.


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You can't be worse off having better bolts, so I would expect some improvement. We'll see if the problem is overcome. Water injection would eliminate carbon build up. It's been used on aircraft before. if I had a jab engine running I would keep an eye on compression and check valve guide wear, and I wouldn't see a top at 300 hours as a bad idea. Don't forget 300 hours is the life of some 2-strokes although they can be known to go a lot longer. The parts are not expensive, the engines not rocket science to work on. You should still know what you are doing if you work on it.. Nev

 

 

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Goodaye all

 

Before l started my quest for my own build l did a lot of research, must be the engineer in me.

 

First conlusion l came to was that the Jab doesnt make TBO often with out major work an cost big dollers to run/maintain.

 

Secondley after reading a lot of horror stories l decided not to trust my life and my familys with one.

 

The engineer in me tells me stronger/touger through bolts are required, at this stage l would say stuff the specs lets go the highest spec l could use and also move up a size.

 

Using a soft sealent on the barrel that moves doesnt seem right to me either.

 

regards Bruce

 

 

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I spoke with one of the Jab reps at Avalon last year and he ASSURED me that they had conqured all these engine issues. That's why I fly Rotax.

That's the beauty of self regulation, if the manufacturer says there isn't a problem, the issue is resolved.

 

 

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@ FrankM. Mate, i know you own a jab... Please be assured I am not attacking YOU because you own a jab. And I picked up your thinly veiled comment about people with no experiance commenting. We've all gotta start somewhere. edit: The rest deleted... not gunna waste my breath

 

 

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Guest pookemon
Just Curios Question... In South Africa where there are more Jabs than 172s... Do they have the same problem as the Aussie built motors?

A quick browse of http://www.caa.co.za/ would seem to indicate they don't. Are the SA motors built in SA?

 

 

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I don't have any experience with Jabiru, I am about to have to decide if I go west to train in a Jabiru or east to train in a drifter 2 stroke so all these discussions are my best chance to make a decision I won't regret what ever Frank thinks. Training behind a Rotax isn't an option down here so I just have to suck it up!

 

 

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I said

 

You guys have got it all wrong

 

Rod mentioned at Natfly that if we are having a problem with the engines (I am) it is because we are all operating them wrong.

 

He said that the reason we are having overheating problems with the 3000 engine is because they are tuned to operate in Bundaberg and we have different weather in Melbourne.

 

I wasnt sure whether he was recommending that all Jab drivers in Melbourne relocate to Bundy or that we get Jab to retune them for Melbourne weather

 

Any suggestions?

 

Cheers

 

Bryon

 

I heard Rod make this statement and was flabbergasted

 

 

 

I posted it here as a bit of tongue in cheek posting to see the reaction

 

 

 

At the time I felt that Rod must think we are stupid and would believe such an idiotic statement

 

 

 

I was angry that he would treat his customers this way

 

 

 

If that is his attitude, maybe he should get out of the business

 

 

 



 

 

 

Bryon

 

 

 

 

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:bash:Hongie

 

In the last 24 hours you would have observed objective and informed statements which are of interest to all.

 

My failed attempt to get it heading in this direction was an utter failure resulting in complete rubbish and Rotax promotion.

 

I am not promoting any product or engine - but rest assured I will not be contributing to threads that are self promoting to some people

 

The lack of detailed experience which has dissaperared in the last 3 years that I have observed I would suggest might be a consideration for IAN.

 

Anyone can run off at mouth but only cause division with opinions which are not changeable or debatable or more important HELPFUL.

 

I am over the third degree on eveything one suggests - The best thing can do is take a back step and watch to see what develops from here.

 

Hopefully things can get back to more facts - good luck:closed:

 

FrankM

 

 

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Guest graham campion
They are all built in Australia. Bob

hi guys well done for getting her down,

but on another note or theory i have

 

should jab motors have egt gauges?

 

why because once a motor reaches 13 on the egt gauge aprox 1300 degrees c the aluminuim is at or very close to its melting point of 1390 degrees????

 

here in albury the local preist was having problems with his motor and over heating 220 t on climb out but his was an easy fix ,,

 

when you look at the air inlets 8 odd inches round x 2 one each side behind the prop,,,

 

and then glance underneath the jabiru designed 2 small cowl flaps?

 

problem is you have to get out what you get in ,

 

his problem was the air was dead heading,and could not get out quick enough and was not passing thu the motor as designed ,

 

having explained the theory he had larger cowl flaps made and the temp dropped down to a nice 160 to 170,

 

but unfortunatley for me father j made the call to jabiru before i could and grabbed all the glory oh well but thats life,

 

just a theory but if it saves motors and lifes ???

 

 

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Guest pookemon
Had a better look at the engine today. It was number 2, not 3. And the cylinder is also cracked at the base.

I'm curious - where did the bolt break, relative to the nut?

 

 

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Guest pookemon
Hi guys. Here's a flight path mock-up. Props to Motz, he's taught me everything I know. I hope you all have as good an instructor as I do.Cory.

 

[ATTACH=full]17398[/ATTACH]

Well done Cory - a great effort - and well done Motz for giving Cory the skills he needed.

 

 

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Guest pookemon
Can we have a sensible anaylysis of each engine failure or do we just do the three stooges thing and only talk about Jab problems.

Why would we talk about other engine failures in a thread that is all about a (common) Jabiru engine problem which resulted in an aircraft being totalled? People are entitled to their opinion - and there are some pretty experienced people - who work in the aviation industry - that are saying that they don't like Jabiru engines. It's all appropriate - if you like your engine, that's fine, but don't denigrate a healthy discussion on something that shouldn't be happening - and something that puts the lives of people at risk. Yes Rotax Engines fail - and yes some of those failures are for reasons that are covered under A/D's - but people still like Rotax's. Why? Because they are a reliable engine - with a good chance of making it to TBO.

 

Our club Gazelle's 912 flew it's last 200 hours with 4 of the spark plugs cross threaded (Yes - really - the 4 lower ones). This meant that 50 hours short of 1500 it needed it's heads repaired.

 

People with experience (like Motz) can put forward what has happened, and people will form an opinion on that. And with stats that 48% of engine failures are due to these through bolts - why wouldn't people want to avoid having their engine break in half on take off?

 

If this were a car engine all Jabiru's would have been recalled and new through bolts would have been fitted at the manufacturers expense.

 

 

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I would add that regardless of whether it is "uninformed opinion" or not... the fact that in my (and it sounds like it is not uncommon) experience instructors, pilots et al that I know almost universally recommend steering clear of Jabiru engines is something that should be of interest to the factory and to ALL who participate in our sport.

 

 

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I would add that it is also IMO interesting that someone can claim that others have a vested interest in knocking Jabiru engines... when that someone has an obvious vested interest in the opposite due to being an owner of the product.... Sort of like the pot calling the kettle black.

 

 

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Whilst it is natural that some who have had a good run will be condemnatory of people suggesting that something must be done, it is in EVERYONE's interest that something be done. I don't believe that we should overreact either but some scrutiny is called for at this stage. Nev

 

 

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Correct me if I am wrong, but the Jab engines are certified engines. I'm wondering how many GA registered Jabs have engine problems, and whether these are the ones that mainly would come to the attention of CASA (or whoever is involved in certification standards)? If so, and they aren't really aware of the numbers of RAA registered engines which have problems, then any interest from a certification viewpoint would be based on incorrect figures.

 

I could be barking up the wrong tree completely, but are certified engine failures not used in GA aircraft reported to the relevent certification authorities?

 

 

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Jab may need top end overhaul early - so what, parts are cheap, easy to work on. Im told not many Lycoming or Conti go throught to TBO without some heads or cylinder being worked on.

 

When adjusting valve clearances (or tensioning lower head bolt) look closely for exhaust burn in the rocker chamber, monitor ALL EGT and CHT, re jet if needed, do regular leakdowns.

 

Some choose to do top end every 300hrs. Still cheaper than Rotax alternative depends how much effort and time you can spend on it.

 

What is the maintenance framework in RSA? Having so many more around means LAME are more experienced spotting problems and maybe do more than standard on services.

 

Im not sure the 2200 is a big seller there though.

 

RSA engines come off same production line as ours as far as I know. There are some guys doing upgrades and improvements over there even on new engines. EFI is being developed.

 

I feel the EGT/fuel distribution problem is a core problem, cylinders can severely lean under different throttle settings and different altitudes (To some extent this might be what Rod S is eluding to) This has been an issue since the first of these engines was developed. Until EFI, even most automotive engines had the similar issues, only water cooling masked the problems. Every engine has differences which needs adjustments and tuning. Rigidly sticking to the book isnt good enough, you have to trawl through websites and forums to learn much of how to make them run well and reliably. With this in mind Jabiru do need to more to enable certified use of the engine.

 

They arent Lycoming or Rotax but a small volume engine maker with problems and benefits that brings, but they are good value and generally perform well but not always.

 

I have one cylinder which goes lean at wide open throttle whilst rest of engine cools as it is supposed to. Punching out repeated circuits with this problem would definitely see it fail. In cruise it all settles out OK.

 

Without EGT monitor would have no idea there was an issue. Ive been doing 25hr leakdowns expecting to see a problem and yep it finally reached limits, had the head sent away, back in five days with new valves, guides tested and head lapped, all I paid was freight.

 

It is annoying to see those on here refusing to fly a Jabiru because of these problems, many with little experience in them. There are many thousands of Jab engines out there and only a few problems. Flying RAA or experimental aircraft is one of the highest risk activities you can choose to do. Id say engine failure isnt the top of the most likely things to go wrong. By far the greatest risk is the pilot, their capabilities and decisions they make.

 

 

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Guest Andys@coffs
All you need to know is that Jabirus are prone to engine failures, trying to understand why doesn't make you any safer.

Well, every time you say something new I think, can it get any more stupid than that and then along you come, open your mouth and Tada!!! a new low.....

 

If we adopted your approach there would be no need to investigate or publish any incident at all, because knowing why something happened wont make you any safer!!!!! WTF Perhaps in this forum we can just talk about somethig unrelated to flying becasue talking about anything flying related wont make you safer!!! So all this time youve been banging on about RAA suck, they never do anything.......which aligns perfectly with what they should be doing according to the statement you just made......

 

What about the guys who have done their own thing and replaced through bolts with ones that are shown to be up to the job at hand...unlike the originals.... probably better for them if they just hadnt done anything and accepted that they would just have to remain as safe as they were before the change.

 

There is a generally accepted mandate that the brain should be in gear before the mouth moves or in this case the fingers type!

 

Andy

 

 

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