Blueadventures

44 minutes ago, danny_galaga said:

Is there a normal overhaul period of hours or years for carbies like there is for rubber hose replacement?

Part of the 5 year rubber.  I only mentioned above because I have serviced and chased issues with a number of carbs and find long time in service 'o' rings are at times hard, worn and break into pieces when the part they are on is removed.  So if you don't have new ones on hand you need to order and await delivery. I keep some parts on hand as I assist owners at times.  Cheers Mike.

7 hours ago, danny_galaga said:

New build airplane  I only put fuel in it when I was ready to start it a couple of weeks ago.

 

Engine is I think 2017, 1800 odd hours on it. As far as I know they are the carbies that were on it when it last ran but admit I can't be 100% sure.

 

I will take the carbies off this weekend and take them home to work on them in a (relatively 😄) clean environment. 

 

I guess strip the major components, soak in carbie cleaner? Inspect for wear/damage of needles/O rings / gaskets etc? 

 

I'll have to find my beam balance weights I made years ago to weigh the floats..from memory they went to 0.1 grams. I'm guessing that will be accurate enough 😄

HI Danny  If your good to clean carby's; you can check them at the field; allow 3 to 4 hours.  Any dismantle of the fuel route components would require at the very minimum the 'O' rings that fit the idle jet, idle mixture needle and the mixing tube (Diagram 'O' rings #9 x four and #5 x two 'O' rings) as you are doing two carbs.  That will allow checking the major fuel route and metering but not include the enrichers.  This will ensure you can reassemble the same day and test.  My recommendation is to fit a carb kit to each carb.

47 minutes ago, danny_galaga said:

I should emphasise, it ran well on the first start, then after 30 or so seconds, roughly. Since then it has not run smoothly. Feels like a carbie issue. Not sure how much fuel will stay in the bowls if I remove the carbies. There's no way of removing them without swivelling the carbies...

Were you still at low rpm, say about 2000 to 2200 rpm or had you increased the rpm a bit at the 30 sec time.

I had an engine (R912UL 80hp) sit while repairing undercarriage.  Then ran rough.  6 weekends of trouble shooting; new o rings, checking for air leaks etc.  Eventually found a build up of crap up around the mixer tube; looked like an o ring.  Then ran absolutely great.  There are many reasons for rough running.  another is your carb bowl vent lines and how they are set (you don't want to extend into slip stream as will pull fuel.  You must take the time and verify the floats are correct and not heavy.  Enjoy the build and carb sorting; look forward to hearing about first fly.

Being new build, engine with hours on it and been sitting. Best to do carb clean, service and mechanical balance as per manual. You don’t want surprises or extra distractions during first and during the next 25 hours.

Did you do correct mechanical balance, o rings dry out and crack, what floats model there is a bulletin on them. Can sink and flood engine.  I’d get a carb kit through them by an experienced person, not hard but follow the manual.

38 minutes ago, Blueadventures said:

A wiring diagram for your model will say if one is fitted.

For info there is a  capacitor for this Jab 3300 engine fitup (Sonex).  Follow R lead from rec/regulator.

4 minutes ago, shajen said:

No, don’t think I’ve seen anything like this . Will double check when I’m over there next.

thanks

A wiring diagram for your model will say if one is fitted.

4 minutes ago, shajen said:

Blue adventures . I’m a bit ignorant, what does a capacitor look like, where would I be likely to check?

Blue or Black in colour, about 35mm round and 75 mm long.  Most likely on firewall inside cabin side but could be engine side.

1 hour ago, shajen said:

RFGuy and Blue adventures, when I bought the radio I also bought the loom to connect from the Microair to the Trig. We’ve had the panel out perhaps 6times since then checking wiring and connections etc.  We have played around with the set up menus so many times I could recite them in my sleep.
it’s still got all my previous intercom, jacks etc. No one suggested I may need new intercom. 
 

 I left the money for the radio guy before I took the Jab home as he wasn’t available to talk to.  It’s a 1 hour flight to see him but he doesn’t seem too interested. The only suggestion from him was that he would rewire it (for about another $700) and wouldn’t use the  loom. If that was needed in the first place, why does Trig sell looms to match the previous radios and recommend purchasing them? 

 

intercom is ok from both sides on the ground, but once power is up I can’t hear anything.

Part of the problem is that the new Jab engine should not be ground run. They say for about 5 mins only for your runups then to take off or turn it off.  And I’m very worried about flying more than a circuit without a radio. Too many others around.

 

Thanks,  Jenny

Have you got a capacitor (25,000mfu type) in your circuit and if so is it still serviceable? (they do ultimate noise)

My trig needs internal adjustment for David Clark head sets for example.

Don't give up, yes it is frustrating at times but must bust through that thought.

Have you adjusted the internal settings, don’t have anything plugged into your usb next time you use the radio.

Great show, weather, food and crowd.

40 minutes ago, skippydiesel said:

".........your unsubstantiated comment that the 912 g/b will definitely last 600 plus hours"  I don't recall saying/writing this.

 

FYI - The Sprag Clutch (SC) can be replaced without removing the gear box. I have replaced one, don't recall any special tools but the aforementioned dodgy memory, may be in play. The SC was one of the Rotax weak points being particularly susceptible to the forces generated by the earlier engine start system (now mitigated by the Soft Start ignition) and the failure of some pilots to replace a weak start battery, as soon as identified as such.

Skip if you reread my post I have not said I need to remove the gear box to maintain the sprag clutch.  I was referring to building on my tool inventory . At the moment it includes tools for example flywheel pullers (long and short) for use to access the sprag clutch. What puller type did you use to access the sprag clutch you maintained?

1 hour ago, skippydiesel said:

No offence Blue but I realy dislike unsubstantiated statements like this.  Reason; they and possibly the reports you have read/heard, are without context (history - service, usage, prop type,  number of similar failures, as a percentage of total in use, etc). All mechanical "things" (technical term for man made object with moving parts) are subject to wear and failure that may be accelerated by poor usage. These days. most will have some sort of in service life expectancy, either through testing or experience - I have not heard of Rotax 9 gear box or engine general failures at 600 hrs or anywhere near this operational time. From geriatric memory - Rotax recommend that the gearbox be inspected (may require servicing) at 600 hrs for engines run on AvGas and  1200 hrs for those run on ULP (reasons are common knowledge)

 

 

Nev  You comments are without doubt based on his extensive experience & training - fair enough however your  "tone" (subjective attribute, conferred by reader/me) does seem to be biased against Rotax 9's, in that some of his technical observations (while accurate) do not appear to negatively effect the service life of these engines. To me there can only be two possible reasons:

• Rotax are good at promoting their engine & hiding its defects ie most of us believe they are one of the few aircraft engines (in their class) that generally make it (pass) TBO without major "surgical" intervention - this may be marketing hype & not be true.
• Rotax engines somehow transcends the conventional engineering wisdom of the past (at least in some respects) -if this is correct, it would mean that you might have to re-examine your training/knowledge.

Skip you read too deep into things and your comment is kinda like mine as your unsubstantiated comment that the 912 g/b will definitely last 600 plus hours.  I was just saying I’m readying myself for when I need to do an inspection.  Like I have the pullers to change a sprag  clutch when the time comes.  Being a maintainer of machinery I build on my tool inventory as my background called on being self sufficient as much as possible.  There have been the failures as I mentioned in my post, in the real world; so you may need to look in different areas to gain the information.  

I am not about knocking engines and I read there are some 912 ULS engines needing gearbox overhaul at less than 600 hours and not Avgas related.  I’m presently putting together a tool box for dismantling the 912 gearbox so I am ready for any such work.  Not saying all just some suffer this for some reason; and can be the luck of the draw, a Friday or Monday assembled g/b or the oil used etc. cheers

The Rotax ones a few years back were made in Austria and probably still made there.  In the UK they had available unbranded oil filters made on the same production line runs that Rotax were made; about 1/3 the price.  I bought 6 of them as they had been in use for 10 years and no issue and were sourced by a Rotax dealer back then.  Had a sticker on them and made in Austria on bottom.  Just for info and may still be available.

9 hours ago, Guy s said:

Hi Mike and I eventually got the new piston and o-rings which were the correct size 😁 I had to get the master cylinder re-sleeve as it had a bit of wear in the bore. Apparently not a easy job re-sleeving a composite master cylinder.

I've got it back together and now I have brakes, it was getting tiring hanging my leg out to brake and not to mention the wear on my Lowa shoes.

Great news, cheers.

Be fully careful about non genuine oil filters; seeing made in China ones on generator sets (<15kva) and the filter shell cracks as it is thin.  And you don't ever what that in your aero engine.

How did your brake repair work out?

45 minutes ago, Thruster88 said:

RFguy and I went this year, like most we stayed at the university of Wisconsin in Oshkosh. Because we booked later we could only get a non aircon room, was not to bad. $322 aud each for four nights twin share. Would probably try for the aircon next time. I slept like a log with just a sheet.

Thanks, trying to book early and get a/c as wife coming with me. 

I'm planning to attend Oshkosh 2024 and asking about what type and price (towards budget end of market if possible) for a twin share is available.  Don't want a 4 or more to a room setup.

Any replies please advise distance to the venue etc.

Thanks in advance for any advice and info.

1 hour ago, GolfWhiskeyHotel said:

Thank you everyone for the input. I don't like putting weight in the tail. But there was nothing to move. The aircraft weighs 6 kilos more than original and 2.5 of that is tail ballast.  I could use a much heavier battery (  12?  kilos ) and place it behind the seat next to the fuel tank, then run much  heavier cables next to the fuel tubing down the centre of the fuselage. That would be adding considerable lbs to the total weight..... If I did the job again I would put the engine and inch closer to the firewall and alter the cowling.  If anybody needs the measurements I am quite happy to supply, The aircraft flies straight and level with the tailplane horizontal.  It can also climb at a frightening angle. Not been solo yet, but I estimate  2000 ft per min to be a realistic number. it also runs a bit too cool, I could have used a smaller radiator, smaller air scoop and carried less water.   Next time I'll know. Thanks again. Geoff

How does your load mass (empty aircraft, you, fuel, cargo etc) fit to the J160 specs being:- 

Forward Limit: 180-mm (7.09”, 18.2%MAC) aft of datum up to & including 440 kg (970lb) 233-mm (9.17”, 23.5%MAC) aft of datum at 540kg (1190lb) Linear variation between points.

Aft Limit 292-mm (11.50”, 29.5%) aft of datum at all weights Datum Wing Leading Edge

Cheers and look forward to your flight feed back.

25 minutes ago, facthunter said:

What does the "weight" weigh?   Nev

That one was just over 7kg, less than 8kg.

7 minutes ago, skippydiesel said:

Wow! that's some lump of non contributing mass - Would have thought they would have done something other than that,to achieve balance - moved the engine forward.

 

Not a good look for Bristelle

It's all relative to being safe for flight; my Blanik glider had shaped lead weight secured to inside the forward most frame, just inside the nose cowl to keep correct w&b. A normal practice like Jabs put lead shot in the tail etc.

On 31/08/2023 at 7:53 PM, Blueadventures said:

Images of mass balance on a Bristelle I took today during an annual.  Bolted to crankcase.