Jump to content

Recommended Posts

Posted

What is the current reliability status of 2 stroke engines. I havn't flown one for over 7 years and that was a Rotax 503, very reliable and the only time it gave me trouble I put it down to carby ice. The bores appeared to be scored when I checked them through the ports, but it was an optical illusion, fooled not only me but one of our best known self proclaimed experts.

 

My feeling is that given the newer designs and better materials in modern 2 strokes, plus far better ignition, and good oils, they are reliable for aircraft use.

 

 

  • Like 1
  • Replies 476
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

Posted

Where ARE the modern two strokes? The 582 is the only one of the Rotax's to continue in production, and it hasn't changed much for a long time. You have to run the oil pump, ( no premix). Well that's whats recommended. I have no real idea what the Hirths are like and a lot of the stuff thats around is old and of dubious maintenence history. Of the new owners purchasing them, how many really understand how to service and judge the condition of a two stroke? Who will teach them? Slightly off topic if you want to be strict, but something to consider. Nev

 

 

  • 2 weeks later...
Posted

It's good to see that a thread I started some years ago is still receiving posts and over 22,000 views.

 

On 2 strokes I've personally had 5 engine failures, all 2 strokes and one more with an instructor present and it was also on my first lesson in an ultralight.

 

With equal offenders being the 582 and the 503 (note these were early models).

 

It's interesting to note that I never had a problem with my single ignition 447 powered Super Pup.

 

These occurred for various reasons from carby ice, fuel starvation and lubrication problems.

 

But I have in recent years found that the much maligned 2 stroke has improved to a point of serious reliability.

 

This doesn't mean that I like them but when one wants to go flying around an old volcano and there is only a very well used S12 available to do so then you take the risk knowing full well that if maintained religiously IAW the service manual then the chance of an engine failure is slim and if it does shut down then thanks to 2 strokes one has had plenty of practice getting it all back on the ground safely.

 

Particularly when you fly over what you can land on if required or at a height that you can get to where it's safe to land if the engine quits.

 

I think that everyone would agree that the 3 most frequent causes of an engine stopping in flight in respect of the modern light aircraft engine are lubrication issues, fuel starvation and finger mentality (caused by those who fiddle with no idea what they are actually doing).

 

For those who don't ever want an engine failure then here is some good advice, buy a glider.

 

Rick-p 080_plane.gif.36548049f8f1bc4c332462aa4f981ffb.gif

 

RICK P, this is a great thread and one which will provide excellent information to Jab 2200 owners. This thread is now only to contain specific posts in relation to the topic of 'Jabiru Engine 2200 Mechanical Problems'. Only specific posts relating to this topic are to be included in this thread. Please use other threads/create new threads for non specific posts. -Moderator

 

 

  • Like 2
  • 3 months later...
Posted

After a long while thinking that the Jab knockers were a bit over the top I am about to change my mind.

 

My 2200 jab with about 230 hours on it since zero timed overhaul by the factory has been playing up.

 

First sign of a problem was a misfire when doing a mag check at the end of a flight.

 

This progressed to misfiring on one mag at any check at moderate rpm. Full power check was faultless.

 

The plugs looked as if they were running rich.

 

The mag with the misfire was replaced and it made no difference.

 

Eventually I had a severe power loss at T.O. and aborted it.

 

I have just removed the heads and find No 3 cylinder very oily. The others were OK. So far I havn't removed the barrels. I removed No3 Inlet valve and the seat was pretty good, but the valve wobbles so much in the guide that I am amazed that the seat isn't burnt.

 

It looks as if I will be putting in new rings and valve guides all round. Not much sense removing the heads and 1 barrel without doing the other 3 that may give out any time.

 

Just what I needed to be doing right now, when I have an RV4 nearly built and the Corby will be for sale in the near future. At least I will be able to sell a more reliable engine.

 

 

Posted

Further update on my engine. A second look at the valve movement showed that it was not worn as badly as I thought.

 

Removal of No 3 piston and cylinder showed the horrible truth. About 25% of the land between top and second ring had broken away and No 1 ring was in 3 pieces. No wonder it was down on power. It appears that the piston could have scuffed in the bore from marks on the piston. Bore is still very good. I havn't had a CHT sender on No 3, but No 1 and 4 have never run hot.

 

I pulled No 4 cylinder and it was in good condition, so I am putting new rings on it and a new piston and rings on No 3. I will leave the valves alone as they are in good condition.

 

Now I cannot say wether it was overheating that caused the problem or some problem with the original parts, but as it has taken 230 hours for the problem to appear I think something happened recently. I had difficulty getting Avgas, the local airport stopped allowing me o fill 200l drums. That meant I used Mogas, Caltex 95 octane, from a high turnover servo. Maybe that caused the problem. I note that the piston crowns have a hard light grey carbon deposit, which is quite thick. Don't know what sort of deposit Avgas would leave.

 

All it needs is money and time. Sounds familiar.

 

 

Posted

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

 

 

Posted

The rings were not stuck and only 1 cylinder gave trouble. That cylinders rings were not stuck, only 1 was broken and the broken land was between the 2 compression rings. the top of the piston looks OK.

 

Unfortunately I can't run the engine hard in cruise as it will exceed VNe easily

 

 

Posted
The rings were not stuck and only 1 cylinder gave trouble. That cylinders rings were not stuck, only 1 was broken and the broken land was between the 2 compression rings. the top of the piston looks OK.Unfortunately I can't run the engine hard in cruise as it will exceed VNe easily

You could fit a finer pitch prop which would reduce your cruise but burn more fuel however, the extra fuel burn is cheaper that possibly glazing your cylinders.

You would also have the bonus of better climb performance.

 

Alan.

 

 

Posted

With a finer pitch I would have less chance of preventing cylinder glazing. The revs would be high but the pressures less. A coarser prop would help with the glazing problem, but climb would suffer and I would have to be even more careful of over revving.

 

 

  • Like 1
Posted

Ian are you going to the flyin at Fitzy's on the weekend, if the rain goes away? 026_cheers.gif.2a721e51b64009ae39ad1a09d8bf764e.gif

 

 

Posted
With a finer pitch I would have less chance of preventing cylinder glazing. The revs would be high but the pressures less. A coarser prop would help with the glazing problem, but climb would suffer and I would have to be even more careful of over revving.

Yenn I agree with your assessment and watch this issue with interest. My little Jodel has similar issues; The only time I can really use full power is on climb. Cruise needs to be no more than 2800 rpm; any more nudges my VNE.

 

 

Posted

Rick.

 

No I won't be at the CDFG do on the weekend. I am waiting for a piston so I can't fly and it is an Old Station meeting on Sunday.

 

Hope to be back in the air soon.

 

 

Posted
Rick.No I won't be at the CDFG do on the weekend. I am waiting for a piston so I can't fly and it is an Old Station meeting on Sunday.

Hope to be back in the air soon.

Thanks Ian, it was down on numbers because of the wind but allthat turned up had a great time.

 

See you next time.

 

Rick-p 087_sorry.gif.8f9ce404ad3aa941b2729edb25b7c714.gif 099_off_topic.gif.20188a5321221476a2fad1197804b380.gif

 

 

Posted
Thanks Ian, it was down on numbers because of the wind but allthat turned up had a great time.See you next time.

Rick-p 087_sorry.gif.8f9ce404ad3aa941b2729edb25b7c714.gif 099_off_topic.gif.20188a5321221476a2fad1197804b380.gif

And ironically and back on thread due to a Jabiru which went into the scrub on its way with no injuries to crew according to a thread posted this afternoon elsewhere.

 

 

Posted

80 hours or so after the rebuild (due broken through-bolts - see previous posts this thread) my 2.2l Jabiru engine has crankcase-fretting, oil seeping out from the front cylinder bases, and pretty clear evidence of impending through-bolt failure. It's heading back up the road to Bundaberg for yet another visit to the doctor.

 

There must be a single word to describe how I am feeling at this time, but the English language appears curiously deficient in the precise term which adequately sums up my present state-of-mind.

 

 

Posted
Further update on my engine. A second look at the valve movement showed that it was not worn as badly as I thought.Removal of No 3 piston and cylinder showed the horrible truth. About 25% of the land between top and second ring had broken away and No 1 ring was in 3 pieces. No wonder it was down on power. It appears that the piston could have scuffed in the bore from marks on the piston. Bore is still very good. I havn't had a CHT sender on No 3, but No 1 and 4 have never run hot.

I pulled No 4 cylinder and it was in good condition, so I am putting new rings on it and a new piston and rings on No 3. I will leave the valves alone as they are in good condition.

 

Now I cannot say wether it was overheating that caused the problem or some problem with the original parts, but as it has taken 230 hours for the problem to appear I think something happened recently. I had difficulty getting Avgas, the local airport stopped allowing me o fill 200l drums. That meant I used Mogas, Caltex 95 octane, from a high turnover servo. Maybe that caused the problem. I note that the piston crowns have a hard light grey carbon deposit, which is quite thick. Don't know what sort of deposit Avgas would leave.

 

All it needs is money and time. Sounds familiar.

Hi. Ian,

What you are describing is typical detonation damage. I see it a lot on high performance turbo engine where the boost has been screwed up to gain more horsepower without any other mods being done.

 

The ring lands shatter from the detonation pulse, so I would be looking at the fuel you are using and in my opinion, if you are unable to get AVGAS , I would be adding an octane booster or changing the timing setting to decrease the ammount of ignition advance.

 

The scuffing on your piston, if it runs in 2 lines down the edges of the piston near the gudgeon pin bosses, indicates a piston overheating issue, whereas if it in a fairly constant coverage over the skirt of the piston it usually indicates a lack of lubrication or fuel wash causing the lubrication film to be broken.

 

The usual things that cause detonation are: Compression too high for the octane of the fuel, ignition timing too advanced for the fuel being used ie: fuel mixture too lean or compression too high.

 

If as others have suggested, the Jabiru engines like to run at full throttle to cool the pistons, i would consider going up a jet size or 2 if you cant run at this setting without going above VNE.

 

Hope this helps. Cheers Will

 

 

  • Like 4
Posted

On the ball above. When you get the new piston remember that some of the circlips are square and some ar round section. Ensure you have the right ones for the piston you have. ( Don't mix them) Nev

 

 

  • Like 1
Posted

No more mogas for me. I have a supply of avgas now. It looks as if I overheated the piston, that is what our tech man says after I did my report to RAAus.

 

Getting those circlips in is a bit of a hassle, same for the rings. One of the oil control centre rings seems to be oversize, but luckily I had a spare and it fitted.

 

 

Posted
No more mogas for me. I have a supply of avgas now. It looks as if I overheated the piston, that is what our tech man says after I did my report to RAAus.Getting those circlips in is a bit of a hassle, same for the rings. One of the oil control centre rings seems to be oversize, but luckily I had a spare and it fitted.

Hi Ian if and when you need more Avgas Roger Toole is the go, if you didn't already get it from him. Send me a message and I will reply with the details.

 

Rick-p

 

 

  • 2 months later...
Posted
80 hours or so after the rebuild (due broken through-bolts - see previous posts this thread) my 2.2l Jabiru engine has crankcase-fretting, oil seeping out from the front cylinder bases, and pretty clear evidence of impending through-bolt failure. It's heading back up the road to Bundaberg for yet another visit to the doctor.There must be a single word to describe how I am feeling at this time, but the English language appears curiously deficient in the precise term which adequately sums up my present state-of-mind.

What has happened regarding your engine since this post? Dave

 

 

  • 11 months later...
Posted
What has happened regarding your engine since this post? Dave

 

80 hours or so after the rebuild (due broken through-bolts - see previous posts this thread) my 2.2l Jabiru engine has crankcase-fretting, oil seeping out from the front cylinder bases, and pretty clear evidence of impending through-bolt failure. It's heading back up the road to Bundaberg for yet another visit to the doctor.There must be a single word to describe how I am feeling at this time, but the English language appears curiously deficient in the precise term which adequately sums up my present state-of-mind.

Hi, did you ever post the results of what the findings were in respect of your engine problems and also did it get repaired to your satisfaction, in end?

 

I'm sorry if you have already posted on this but it is just that I can't find anything and I am interested in the mater.

 

I started this post some 40,000 plus views ago in the hope that all, if any, of the Jab motor's continuing problems could be gathered at one point and then followed up with the factory to see if some closure could be reached in having the reoccurring problems being addressed and dealt with on an engineering platform rather than through just discussion about them.

 

Rick-p

 

PS Some of the people in these posts have come up with great ideas and constructive comment whilst others have been nothing more than bashers so lets now take this to the next level and get some results.

 

 

  • Like 5
Posted

The general evidence keeps pointing to detonation. No-one has ever mentioned plug heat range. Fuel quality could be the culprit in some situations. There is no real regulation of mogas whereas avgas is a controlled product. There is an extra risk using avgas. Mixture distribution seems to be a common problem with EGT variance being common as a result. A lean mixture behaves as if the octane rating is lower. That is why take-off power is set up rich. If you have one lean cylinder it may cause damage. The hotter running engines would be more susceptible. Exhaust valves run red hot at high power and could be a factor in detonation.

 

Is everyone running 98 ? Nev

 

 

  • Like 1
Posted

I have X-Air S fitted with Jab 22A 1261 which I think is on its second life. reconditioned at Jab after service in France. solid lifter. Total trouble free hours 294. Richer jets fitted at 252 hours as per JSB 018-2. Still easy start and smooth running. No sure but think I have 285 needle and 225 main. jab invoice has this as Item No, 4A172AON.

 

 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...