Jaketab

My Feedback: (2)

Coil housing and intake tube

Maxam

My Feedback: (62)

Removed

Maxam

My Feedback: (62)

OK, To set the record straight, Gotz from Vogelsang Aeroscale had a complication from surgery so he is now recovering and working hard to catch up. He has taken care of my issues with great care and professionalism. A true gentleman. -Tom

Scott Prossen

I knew he would have a good reason! He's always been the best of people to deal with.....A true professional!!

Scott Prossen

jetpropdlx

Can you tel me , what kind of valve do you mean ??
My moki just returned from airworld for service and i did install the turbulator and fuelpump (380) .
After turning on the fuel pump, fuel starts leaking out of the Carborator after a few seconds
(i bought this old moki 215 from Mick B. 2 years ago and hope to get the model for it finished this year )

any idea how i can solve this. When the pump is on to long the engine is over primed and is hard to start
At this time i installed two switches one for the ignition and one for the fuelpump and removed the servo for the choke.

once running, it runs well ( 32x10 @ 5000RPM )

Thanks in advance

Eric

mick15

Yes collected it from Pampa jets I remember it well. How are you Eric?

It's about time that engine saw some more air time!

As said earlier the demand valve is not closing, you need to remove the two covers and have a bit of a clean out. The one you are interested in is the one with the metal insert, lift it off to reveal a small rocker held in with a screw. Remove that and the needle valve will come out it probably just needs a clean.

m

Jack Diaz

My Feedback: (1)

Hi Scott, ditto on your comments about Gotz. Very responsible person.

He is facing a major headache when it comes to repairing engines, though: AirWorld is not supplying parts.

To illustrate the point: I sent him my 250 on november for maintenance. To this date, and regardless of many emails and phone calls to AirWorld on the subject, we still have no idea when the required parts will be shipped to him from the factory.
So, I decided to buy another engine (I got it already). I may sell the other one after it gets overhauled.

On another subject, I have one question. When you guys refer to cylinder temperature: where is it measured? on the black cylinder side, or on the cylinder head?
There is a difference of about 20 deg F between both measurements (engine running).

See you at Top Gun

Jack

BIGDAMMODELS

I check between the rockers and at the exhaust pipe nut closest to the cylinder head..but would think that if you check each cylinder in the same general area it would give maybe a different temp reading than the other per say, but readings should be very close to each other provided the same check point ...good to hear Volgelsang is ok...and good luck at Top Gun...hope to see you there...any clue as to why Moki parts are being delayed?...Bill

mick15

If a company refused to supply spares for one of it's products in the UK it would be found to be breaking the law.

m

jetpropdlx

Hi Mick,
yes, I can't wait to get this bird ready and fly the moki

I'll will check the input needle later this week or in the weekend.

Thanks mick ,

Jaketab

My Feedback: (2)

Reference to my #4 cylinder not firing, I discovered something today about the CDI. Not good with electronics, but I'll attempt to explain.

Checked the 10 pins on the back of the CDI with an Ohm resistance meter in the K-scale.
These were each tested against the center pin in the round quick connector.
All pins read .000 to .010 thousands except for one pin.
It read 22.66 thousands.
The pin giving the higher reading was on the bottom row, 2nd pin from the right.

In other words - one pin was different from the other nine.

Could this mean anything???

Thanks - J Tab

Blackwidow

Guys,

Does anyone know what the max current draw is on these Moki 250 iginitions?

Isearched theforum and the question has been asked several times but Ihave not found the answer.

Thanks in advance for your help!

Straightleg

I measured it some years ago, and if I remember right, it was close to 1 amp at full throttle

/Straightleg

jetpropdlx

Today cleaned the input needle valve and adjusted the "L" needle
After that everything was fine re-installed the choke servo
Thanks for the advice (mick and Gerd)

@Jack Diaz,
My moki has been away for almost 4 months for service at airworld.de

wayne d

My Feedback: (5)

Hey Guys
Yes we are still making props. We only do this part time as my wife and I have full time jobs.
I'm sorry if I have not returned your Email. It may not have gotten to me for some reason. Phone calls are hard for me to return, I work midnights during my full time job so I sleep most of the day. By the time I get to the phone, after all the normal activities for the day its late. Sometimes to late to call. Email is always the best. At least I can answer them while I'm at work.
Just to let you all know, I was out for almost 3 months with some heart problems late last year and that has put me so far behind the eight ball its not even funny. Thats one of the reasons we have the business for sale.
Hope you all understand.

Blackwidow

Guys,

Wondering if you guys are using standard Tygone fuel tubing to pump smoke oil into your exhaust rings. The only nipple Icould find in my spare parts drawer that fit the thread is only about 1/2" long and Iknow it will be at the same temp as the exahust ring. Just wondering of the tygone can handle those temps or if Ishould either use a different (maybe automotive) type tubing.


Wayne,

Glad to have you "back" ! Ireceived the scale curtis electric prop hub and it looks GREAT! Can't wait to see it on the CARF P47! My 4 bladeprop and hub are still MIA from CARF. They may be on back order not sure yet. Anyway good to hear from you!

Scott Prossen

Hey BlackWidow,

I use a black Buna Type line that is heat resistant and smoke oil resistant. You can see it online on http://www.sullivanproducts.com/Fuel...sMainFrame.htm

I've learned early on with tygon and heat. It can melt and spray smoke oil all over. A real mess!

Good luck,

Scott

mick15

I use 3or4 inches of ordinary silicon fuel tube, works fine.

m

heinzulrich

OH yes, tygon and heat don't mix. silicon should be fine. Tygon cost me a motor rebuild.

BIGDAMMODELS

Hey all...some may have seen this....some not..but interesting nonetheless...as we have seen through the post here the Moki does have a tendency to fail on the #3 for some owners...this shared info fits well with the problems we have seen here with the cyl temp/ coil misfire/#3 issues...anytime a coil is subjected to such, a failure is for sure in the future for some if not all Moki owners...with such variables contributing to each situation let us be reminded that each and every bit of info shared will help us move forward in the betterment of model Aircraft and success with our investments to such...as I've stated in previous post this only helps verify that the issue is more gravity related...which explains why the engine run so well mounted vertical....I still feel that some tweaking with the overall carb and intake design would make for a better running engine with lesser issues on #3...Thanks for sharing this D...hopefully we all get some benefit and better understanding of Multi-cyl engines and some strange ghost type issues that maybe surprising to learn and help many at the same time....there's a RCU video on the tube...I tried to copy link but had issues for some reason....http://youtu.be/_rGSoGPW_W8...Bill





-Gene Payson
R Radial Test Corsair - This is a 100" Meister Scale Corsair which I purchased used from a local builder. It had many flights on it. The plane is just OK looking, with just one of the three sets of flaps, the covering not too good, and air retracts which did not work too well. However, it is a good test bed for the Moki 150 radial. YouTube Video HERE!

The first few flights were without the cowl. I used the standard spinner for use with an electric starter. The first time I started the engine I could not start it by hand. With the electric starter, after about 4 seconds with the choke off the engine started. After this, subsequent starts, even days or weeks later, did not require the starter, though I left the spinner in place just in case. We eventually removed the spinner and installed the cowl. While the plane was well balanced without the cowl, the weight of the cowl made the plane nose heavy. We are moving the batteries back to compensate.

We used Pennzoil air cooled oil at 32:1. This seems to be too much oil. We put the Hitec telemetry system with temp readout on the #3 cylinder. This cylinder is notoriously cooler than the rest and often times will drop out if the engine is set too rich or if there is too much oil. We were able to monitor the cylinder temp remotely using the Hitec system. The #3 cylinder remained cooler than the rest, though inverted flight brought the temperature up to normal. We proved that it was a gravity related issue. On yesterday's flight we must have flown too long upright, too rich and with too much oil. The #3 cylinder apparently dropped out because the temperature was about 110 degrees. Flying inverted for an extended did not increase the temperature. Therefore the plug must have fouled. More tests to follow.

We did see an improvement using a velocity stack in the engine, but we did not install one on the Corsair yet. We will install it later for testing.

Special thanks to Jon Hay and Jeff Tedford!

-Gene Payson

jeff naul

My Feedback: (16)

finally a break through with my engine! I've always ran 100LL AV gas. My dropping number three went away simply by switching to 87 octane. So far 6 flights with the castrol oil that Goetz suggested and havent stuck a valve yet. usually stuck a valve on the fourth flight when I ran klotz. flew again today and could tell that I had more power just by how it pulled through loops and my plane is heavier now. next I'm going to baffle per advice from scott Prossen. I couldn't tell of any power loss during the flight that I used to see. this was the second engine that getting away from AV gas fixed. Jeff

Pelle Gris

Hello.

I posted a question regarding the Moki 250 in the gas engines forum, but got no replys. I´m not trying to spam the forum, but maybe those that may know the answer, have not seen it there, so I´m posting it again here.


I´m considering buying a Moki/RCS 250 radial, and I have worked myself through most of the huge thread concerning this engine in the "Warbirds" forum.

One thing that many suggests is to use an electric fuel pump, like the APS 380, to stabilise the fuel supply, and avoid the possible problem of a clogged vacuum pulse tube, which could lead to a lean run, and possibly shut the engine down.
When doing so, you are instructed to remove the tubing from the engine driven pump to the carburettor, and rely fully on the electric pump.

In my view you then have exchanged one failure source with another possible source of failure.
If the engine driven pump fails, the engine stops. If the electric fuel pump fails, the engine stops.

Is it not possible, to use both at the same time, thereby providing true redundancy?

Looking forward to your input.

mick15

Tinus, as a long time user of the Moki, both 215s and 250s I will attempt to help.

When I first used my 215 it had a number of problems, well understood today one of which was the pulse generator system my first twelve or so flights resulted in dead stick landings. My remedy for this was to fit a fuel pump confident in the belief that I was suffering from fuel delivery problems. I had at this time been moderately experienced with turbine-powered models so I had a high quality fuel pump spare, I was able to experiment from stuff I had in my handy draw.

The final cure turned out to be thus :-

Jetcat fuel pump (Hausl) driven from a Flightpower 7a speed controller from a channel mixed with the throttle. This channel has a rotary trim enabling a degree of in flight mixture control. The delivery is from 4mm tube and has a 3mm bleed off loop back to the tank to prevent over pressurisation, you only need 4psi max. This set-up cured the problem completely. You know how it is, you find something that works so you tend to stick with it. I did try to run both systems but this led to too much fuel pressure and rendered the carb difficult to adjust, plus if one part of the system were to fail the engine would stop anyway because of the resultant mixture weakness.

The latest system I am running on my 250 is basically similar, Flightpower controller driving a Flightworks 100 pump modified for petrol, plus I now don’t bother with the throttle mix I just trim the channel with a rotary knob, seems to work well.

To sum up, I use this system because it has proven reliable, I fully appreciate there are people having good results from the standard set-up, this also makes cold starting easier because you can get instant fuel pressure.

m

Pelle Gris

Thanks for the clarification Mick.
I thought that there must have been a good reason for not using both system at the same time, and an elevated fuel pressure, with both systems operational, would indeed leave you in the same mess if one of the systems failed. Too bad though.

I have talked to two friends flying the Moki 250, both using the APS 380 fuel pump, and both agree that the engine runs more reliable, and with much crisper throttle response with the pump.
So I will most likely follow suit and use both fuel pump and turbulator.

One more thing.
I know the websites of the companies selling both the engine and the fuel pump, but have been unable to find anyone selling the turbulator, other than Vogelsang in the US. But being located just north of Germany I would rather like to avoid having to order the part in the US, and having it shipped back to europe. My modest contribution in the fight against global warming...:-)
Do any of you have a lead on where to buy it?

If I buy the Moki it will be going into a 1:3 Scale PZL Wilga I have been working on for some time. It was originally destined to recieve a King 140 twin, but (luckely) it developed some problems, and I thought the best cure for the following depression, would be to buy a nice shiny new toy. :-)

Detlef Kunkel

Pelle Gris,
I agree with Mick concerning the double pump use. Don´t do that.
If you ever had the chance to compare a 215/250 with pump and turbulator to an engine out of the box, you will see a noticeable difference.How smooth the running characteristics are, how easy to adjust both needles as they show aprecise clean peak position- it couldnt be easier . I have also the new Moki180 here and will be going to run that in my Ziroli Hellcat. Concerning the running behaviour- its just the same.
Yes it runs out of the box- but thats all. Compared to the tuned version now, you would´t want to go back to the "out-of-the- box-" status.
Its a pleasure NOW.
The chance to have a failure it the electric pump is nothing compared to the permanent problems with the built-in pump. It doesnt produce enough fuel pressure, and is very sensitive to pollution with grease in the tube line. The engine gets hardly enough fuel, and the main needle is NOT the regulating factor- its the pump performance. And thats not the way Walbro designed their carbs.
Try to make it run TOO RICH - you cannot, as the pump does not deliver enough. It will drop a hundred rpms- thats all.