Microlighters

Well Done Larry,
I just missed you at FAPA on Friday during my Coast to Coast trip,
Apparently you just took off before I came in to land, would have loved seeing her first hand.

AndyCAP wrote:

by RV4ker on Fri Nov 21, 2008 1:51 pm Congrats..... 160 - 37 is a huge speed range. Looks like Awesome machine

the Magic 4:1 ratio - which most designers strive for (but few achieve)
put into perspective - C172 - 110mph - 49mph (yeah I know its a lot less twitchy )
Do yourselves a favour and go look how many (actually few homebuilt aircraft even get close to that 4:1 ratio ... most are in the range of 2.5 or 3:1
Impressive stuff - good luck Larry & team

Yip only very good designs get the 4:1 right, my RV is also one of them
180HP version stall 51mph topspeed 210mph, the 200HP is even better stall 51mph top 217mph.

Rudi

Hi Rudi - others

Yes, sorry I missed you, but will catch up sometime.

OK, so on a go-around two mornings ago - sudden application of full power - I had a loss of power, and the plane settled back onto the ground.

That evening, tried running up, and when getting to about 2500 rpm, engine starts running very roughly, coughing and spluttering.

Have spoken to jab factory, AP etc. No loose hoses or fuel lines. Jets clear. Same with scat hose inlet removed.

Exhaust very black and sooty - rich mixture.

Have removed carb, and am sending overnight to jab factory. Len wants to replace all jets, as for the 3300.

So, no flying for a while!

Have a great Christmas, all!

Cheers

LM

What does FBA stand for?

Fcuking Beautiful Aerie

That's a pity Uncle Mac... I'll be down there from the 28th dec until the 5th jan - I'll still come visit, even though I can't take her up

Cheers... regards to Auntie Sharon...

Seems there are 10 in SA

Looks like my engine problem might be bad??

Have chacecked all fuel and air options - replaced carb etc.

Now find :


Following our conversation, about the problem I am experiencing on my engine.

Last flown on 12 Dec 2008
Hours flown - 9.5
Previous problems - Experienced an Engine burble, which seemed to not be there with fuel pump on, so presumed to be the gascolator.
On application of full power for a go-around, I experienced a loss of power.
Subsequent engine running only allows the engine to achieve approx 2500 rpm, until the engine starts running very roughly, missing etc, with no increase in power or rpm.
After trying everything conceivable relating to fuel and air, we tried a blow by test, where all 4 cylinders read between 68 and 72
Removing the tappet covers has revealed that various of the rockers (3) have up to nearly 10 mm of freeplay - this with the engine hot, approx 20 min after running the engine.
Cylinder no 1 seems to have no problem, rockers remain tight.
Cylinders 2 and 4 have a loose inlet rocker
Cylinder 4 has a loose exhaust rocker

Waiting for an answer from Jab factory.

L

As they say in the flatlands STRONGS....

Hi Larry,

Is this a Hydraulic tappet engine? If it is then that play should be gone when the engine is running.

Also check if a rubber in the inlet system has a crack or if there is some other leak but then I am sure you have already done this.

Obstruction in the inlet system? A control flap doing something it shouldn't?

Carb Heat plumbing? Do you get a +-200 drop in revs, on run up, when applying carb heat? Hot air from inside the cowling to the inlet system is often not enough to prevent carb icing.

Have you done a fuel flow test, ie is the Fuel supply to the carb 150% of what the carb requires when airie is in climb attitude?

You will only find the problem by working on one area at a time.

Eish hope you find the problem.

Kind regards,

Gunter Rostek

Our AP and AMO visited on Saturday. On Jabirus intsructions he opened one of the Rockers, and removed both Pushrods.

One found to be about 6 mm shorter than the other, very obviously worn down. Opened the oil filter, and found plenty of metal filings and bits and pieces.

Jab now mutter something about a bad batch of pushrods, which never had the points hardened. Waiting to speak to them about replacement parts, labour costs, guarantees etc.

What if I was dead, with a broken Engine?

LarryMcG wrote: What if I was dead, with a broken Engine?

Pilot error

PS
What were you saying about not liking VW's

LarryMcG wrote:
What if I was dead, with a broken Engine?

Very valid question Larry.

Will Jabiru now issue a AD to check all engines fitted with non hardened Pushrods:?:

Are CAA aware of this?

I hope Jabiru repair this engine for you quickly at no cost to you.

Kind regards,

Gunter Rostek

This is really scary stuff! You go to the trouble of buying a new engine and then this....? You must definitly take this further Larry!!

I tend to agree with George regarding the VW derivitives. When I was looking at partnerring in a Sonex last year I decided to seriously consider the Aerovee engine - firstly because of cost, but secondly because I could build it (the engine) myself and then I know it would be assembled correctly. Unfortunately, one hase no chance of visually picking up that a component has not been hardened properly - or hardened too much. So I suppose that building the engine yourself does not guarantee that one would not have such problems!

I suppose one can say "well you get what you pay for" when comparing non certified vs certified engines. Never the less I do not expect something like this from Jabiru!!

It must be very frustrating for you - but like you pointed out at least you were not injured/killed due to this!
Please keep us updated & Good luck!

Ok, so this is what Push Rods shouldnt look like, especialy after 9 hours of flying!!!

The good news is that she should be airbourne again today!

LM

What have Jabiru got to say for themselves?? Did they pay for the new parts & labour?

Happy to hear you will be airborne again soon - Good luck!