Reading the Jab dipstick

[Methusala]

Do other pilots here suffer the same degree of difficulty in reading the oil level on a Jabiru dipstick as me? I think that I am reasonably competent in these small manual tasks. But, no. I am not confident of seeing an accurate indication of this at all. Any positive suggestions guys?

 

 

[lyle janke]

i made the decision while cammit were still around to replace with there dipstick

 

so easy to read level

 

was basically the same with a flat end with a whole bunch of fine holes in flat end in which oil stuck to indicate level

 

so much easier to see level

 

sadly they aren`t around anymore

 

i guess you could mod the jab 1

 

 

[Peter Anson]

Have the same problem but a friend showed me a neat and simple trick - lay the end of the dipstick against a bit of clean rag or paper towel. The oil soaks into the towel and shows up better than on the stick.

 

 

[jetboy]

I dont have any problem reading the level on the dipstick however its not consistent with the sump level because the rod can pick up oil from the sides of the tube when being withdrawn for the reading.

 

Particuarly after adding oil, get a false high reading. Its easier to look down the hole and see the level in relation to the lower end of the filling pipe.

 

 

[Old Koreelah]

It's really only a problem because we change the oil when it's fairly new and clean. While we're on the topic, does anyone know if there's been a change in the colour of AeroShell 100+?

 

I bought a box of bottles and a couple are a much darker shade.

 

 

[Yenn]

I havn't noticed any change in Aero Shell 100+ colour.

 

I don't use the Jab dipstick because I have the engine in a taildragger, so it is about 15 degrees off level.

 

I use an old toyota dipstick, push it in until it stops and it should have 12mm showing. Too much oil just gets blown out of the breather.

 

 

[Old Koreelah]

Yenn I still use the standard dipstick on my tail dragger. Raising the tail to level the engine doesn't make a huge difference, but next week I'll check exactly how much when I change the oil. I'll also drain the catch bottle to see if blow-by has increased - I've done a few trips lately with the oil level further up the stick than normal.

 

 

[Methusala]

On a slightly different matter, the Jab that I now own is installed in free air and has no alternate air source. A few weeks ago, another pilot was flying at around 8,000ft when he experienced loss of power and extremely rough running. He put down in a good paddock and the a/c was flown out later after being checked by a L 2. I have bought an electric carb heater which is fixed to the throat downstream from the fuel jets. The theory is that the body will heat preventing ice from accumulating in the carb throat. It is said to draw 5.5 amps when both heating elements are in use. Has anybody got experience with this type of device? Don

 

 

[Nightmare]

I had this same problem, hard to read, and as others have said here, the stick would catch oil on the tube as I put it in... very frustrating. It would sometimes take me 15 to 20 minutes til I could get a read I was confident was ok to fly with, I even used the method of laying read end on a clean rag or paper, still with inconsistent results.

 

So I called Jabiru and got a new dipstick that has 3 holes on the read section, which catches oil if it is at the right level, and it has a zig zag part just above the read section so you can guide the dipstick down the tube without getting the read section contaminated.

 

 

[barro]

On a slightly different matter, the Jab that I now own is installed in free air and has no alternate air source. A few weeks ago, another pilot was flying at around 8,000ft when he experienced loss of power and extremely rough running. He put down in a good paddock and the a/c was flown out later after being checked by a L 2. I have bought an electric carb heater which is fixed to the throat downstream from the fuel jets. The theory is that the body will heat preventing ice from accumulating in the carb throat. It is said to draw 5.5 amps when both heating elements are in use. Has anybody got experience with this type of device? Don

I have fitted a 12v carby heater to my J230. A push button brings in a latching relay & preheats the throat. As soon as the starter is engaged the relay drops out. Good for cold starts.

[Bruce Tuncks]

Methusala, had that guy who had icing at 8000 ft been using carby heat?

 

And is that electrical heater a length of resistance wire wrapped around the outside of the carby?

 

 

[barro]

Methusala, had that guy who had icing at 8000 ft been using carby heat?And is that electrical heater a length of resistance wire wrapped around the outside of the carby?

The heater is a propriety heater used on motorbike carby's such as Yamaha. It's about the size of 5\16 - 1inch bolt. I assume it filled with carbon.

[Methusala]

Here is the link to the electric carb heat device that I have bought:

 

https://www.motionaero.com/dual-heat.html

 

I have not installed it yet but, on test, the elements have not produced any heat at all! I find this difficult to understand and have written to Motion Aero for some explanation. Each element measures 2.4 Ohms resistance.

 

Bruce, There is no carby heater installed on our engine yet. It is only a possibility that the rough running was caused by icing Around the identical time of this event one blade of the Warp Drive prop shed its thin metal leading edge protection causing a distinct imbalance and I suspect of causing the power problem. I have read on Jabiru forums of engines that over 3,000 hrs of operation have not suffered icing. The carburetor is located very close to the engine in the downstream air path and the induction system is very close to the underside of the engine. Perhaps this creates enough heating effect to prevent induction ice being a problem. I don't know. I am in the early stages of becoming familiar with Jabiru. I am very favorably impressed with the smoothness and the tractibility of it so far. Not very impressed with the Motionaero accessory. We'll have to see what they come back with. Cheers Don

 

 

[Bruce Tuncks]

Carb heater...

 

Thanks for the pics Don, it looks like a good idea. It certainly should make heat on test. 2.4 ohms will give 5 amps at 12 volts and 60 watts of heating. There is nothing much could go wrong with the device except for going open-circuit, and you have already checked for this. Try and measure the current when on test.

 

Icing.....

 

In my experience ( 600 hours of Jabiru flying ) ice sure can happen, but rarely , so it can catch you by surprise when it does. I have had 2 instances of carby ice and in each case I had not thought to apply carby heat before the event like I should have.

 

On prop balance...there is 7000 G's of centrifugal force at the prop tip. So there is 7 kg force for every gram of imbalance, and I reckon you were a bit lucky to get away with losing that leading edge metal sheet. I bet it weighed more than one gram, although not all of this weight is at the tip of course.

 

 

[Methusala]

G'day Bruce. I weighed the remaining leading edge foil at 5g. I think that the greater force would have been the chaotic aerodynamics of it in the process of peeling off. i agree that it could have been more destructive than it was. I will try to measure the actual current draw. Perhaps the heating elements are designed to operate at more than 12v? It is recommended to run 1 element at cruise and add the 2nd when taking off, descending and when icing effects are apparent. Off of course when starting.

 

 

[Richard Budge]

Yes, I agree, I've always found it not only difficult to read, but just as awkward to put oil in. I found that by inserting the stick so that it's just resting on the thread, you should see just a little knob of oil at the bottom of the stick, but do it several times to be sure. It's a real pain in the ass. One day while flying I noticed the oil pressure well down into the yellow arc, and I was concerned enough to put the a/c down immediately, just to find it was well low on oil, and yet less than an hours' flight ago, I "thought" the engine had plenty of oil. Generally a poor design and a well known problem.

 

 

[Bruce Tuncks]

Don, the pics show the two elements connected in parallel. If they are each 2.4 ohms, they will each draw 5 amps at 12 volts.

 

Now 12 volts is a nominal figure, the 13.5 volts they quote in the ad is more like what you would see in flight with an alternator going. This will give a bit more heat.

 

You may need to check to see if the alternator has the capacity to provide an extra 10 amps if both elements are to be used.

 

Good luck and tell us more when you get it going. You should be able to feel a warm carby on a cold day.

 

 

[Methusala]

Bruce, the current draw at 10 amps would be approx 130 w. The book says that the Jab alternator is good for 180. Should only have the 2nd element operating for short periods. That's the theory anyway. Don

 

 

[biggles]

The d.c. output for Jabiru 2200 engines, up to engine S/No. 22A-2661, is 10 Amps,.... Bob

 

 

[Methusala]

Biggles, my error, 140w equal to 10 amps is correct. Judicious use of electric heat is required. A/c is fitted with a volt meter. Still very much in experimental mode. Supplier reports many of these units have been supplied (mostly in the States I imagine) with few problems. Always learning. Don