Greg Wright

My Feedback: (6)

I have 2 Moki 250's and they both get full power at full throttle. What they don't have is any kind of throttle range between half and full so what i have had to do is put a throttle curve in the upper range of the throttle stick so that i can have some throttle management in the upper stick settings.

Maxam

My Feedback: (62)

A bit of clarification, It is no problem to adjust the needles so the engine will keep increasing RPM to full open throttle with a fuel pump especially. The problem is then the engine will run too rich from 1/8 throttle to 3/4 so 1 or 2 cylinders are not really firing in this range (the engine sounds "blubbery"). When the engine is adjusted to travel to 3/4 (full on radio) the high speed needle is screwed in a significant amount to achieve proper tune at "full" throttle. The RPM loss is very little and the benefit is an engine that runs much better with some richness from 1/4 to 1/2 throttle, and better everywhere else. -Tom

Straightleg

This is true, GeorgiaFlyer! You can also ad mechanical expo to the servo arm, to ad up !
In this way you get the best stick resolution.

/terje

ukmike

Hello all.
Have just received a Moki 180s from Airworld in Germany and the ignition unit supplied is the blue alioy cased type.
It has no instructions as to the wiring of the MPX power connector or what the two led's are for.
Would appriciate any help ?
Mike.

GeorgiaFlyer

the three end pins get soldered together, one side for positive (red). The other side for negative (black)

CH Ignitions

My Feedback: (11)

I have seen those behaiviors on some engines I convert.
I will not expect that from a MOKI engine.
The couple Moki I had in hand they all went FULL RPM on FULL Open carb.

Just try this:
When you are at 3/4 and you see that you start loosing RPM ; close the choke a little and see if RPM picks up.
and keep going like that and see if you can open throttle full and keep RPM's and not loosing.
Then you may have a carb issue may not get enough fuel . Try to clean carb, check the metering valve....Assuming that moki paird correctly the carb with the engine.
If the air does not have enough velocity passing trough the venturi and suck the fuel out trough the HI circuit...the venturi may be to big or a dirty HI circuit.

Adrian

badangle

My Feedback: (1)

I posted an see to sell Moki 180 radial under "Engines&motors-Gas engines- radial"

ukmike

Thanks for that Georgiaflyer.
BTW, one led illuminates when the ignition is on and the second led lights when each coil fires.
Mike.

Maxam

My Feedback: (62)

I went to the Dawn Patrol at Dayton AFB Museum yesterday. Many great model planes. A gentleman had the Moki 250/7 engine. I was quite impressed with its smoothness and running qualities. Sounded excellent and idled way down to I would guess 400 RPM. Good transition with throttling and without baffles in a WWI style cowling ran cool! The owner is thrilled with his engine and has over 100 flights. The engine is good looking too. -Tom

snauwaertj

Hello,
Today I fired up my new moki 400 for the first time. I use Aspen for feul and a emcotec feulpump to feed the carb. The first time I made it run, I noticed it ran way to rich. So after leaning the L needle a little I ideles @ 600 rpm.
Then I checked all the exhaust themperatures to see if they all fire.
The exhaust on cilinder number 3 stayed cold. I cleaned the sparkplug and checked if it ignited, and it does. I repeated this a few times, but cilinder number 3 refuses to fire when the engine runs.
Is there someone who can help me?

kind regards Johan

Straightleg

Replace with a new one.

snauwaertj

Today I fired up my 2end Moki 400, exactly the same setup.
Afther a bit off running, I had exact the same problem, cilinder number 3 does not fire on this engine to. This can not be coincedince so I started leaning the L needle, this gave improvement. The same time I richened the H needle to make sure it does not lean to much.
The question is how much leaning can I do on the L needle? Can I lean just until acceleration starts to fail an then go a little bit back to the rich side or will my engines not like this on the long therm?

mick15

Would you care to explain your starting procedure?

m

snauwaertj

1 Feulpump and ignition on, choke valve closed and half throttle swinging the prop until the engine barks.

2 choke valve open, high idle swinging the prop until it runs.

mick15

Yes and that could well be the problem, These engines only fire on the two lower cylinders at hand start speeds, furthermore number three first.

What happens is the No3 plug gets wet and the incoming charge aggravates the situation.

Try this:- Rest the carb needles. Clean the plugs. Ignition on choke closed turn by hand holding on to each blade in turn, when you feel the first "bump" set choke to 50% open throttle a few clicks, Flick hard, engine should start immediately and continue to run on all five cylinders.

m

snauwaertj

Sounds like a great way to lose a hand!

mick15

Very droll, been using these engines for sixteen years, last time I looked I still had all my digits.

m

mick15

A few words to those who are concerned about loosing a hand or digits. A piston engine has crank angle advantage and disadvantage, when cranking slowly by hand the engine will fire at about 5degrees before TDC so the "bump" is at virtually TDC where the engine cannot produce any power, the power is delivered when the crank is at right angles to the piston. Therefore when turning the engine holding the propeller it is impossible for the engine to start.........................................trus t me.

m

Jim.Thompson

I want to trust you Mick, truly I do!
However, my big two stroke Stihl engine will kick back sometimes. It has done so and will throw the "chicken stick" out of my hand and send it flying 3 or 4 mtrs.
There is absolutely no way I could be persuaded to flick my engine by hand. I was warned that the trailing edge of a prop on an engine of this size (100 cc), can, and will take fingers off if treated with contempt!

Jim.

Dzordzik

Hi Maxam, I bought before some time Moki 257, 250cc 7 cylinder. Incredible engine, still in run-in process. I made some video - look if you are interested.

This is after 4 liters on 1:30, now 1:50 with Valvoline Synpower 2T oil (full synthetic) and with really big 34x14" scale prop. Absolutely no problem for this engine. Spin up is very fast and idle is around 700 rpm.

https://www.youtube.com/watch?v=T-FT...ature=youtu.be

Lowest idle is between 400-600 rpm, stable with fast spin up.
https://www.youtube.com/watch?v=yRqyxPW0o1s

Maxam

My Feedback: (62)

Thank you Dzordzik! That engine sounds really good. That prop looks impressive and a bit scary. Are the intake tubes bolted to the crankcase or slid into the manifold with white sealer like the moki 150. Good video. I have concerns with you using the display board as a mount....eeeek! They are made of a low grade particle board. Your video is motivating for me to get one of these engines. Thanks again! -Tom

Dzordzik

Hi Tom, thx for reply. About engine, I´m sure that with APS pump it will run better than now because I cannot set L needle as lean as with pump but pump is another thing that can go wrong, is expensive, not much reliable and must have another battery pack. As is it is working solution out of box. About board, I know this and I´m careful and before every run I was checking bolts and board structure.
Want to ask you, which capacity of akku you think I may use? Now, only for testing, I using 2S Life 850mAh wo problems but it is only for 1-1,5h run, not more.
About fuel consumption, this thing is very economical. For 1,5h of testing on ground It use only about 1-1,2 liters of petrol. Totally different that 2T boxer with same power.
About temperatures, I try to measure some temps on ground ad was around 90-98 Celsius after long idle on each cylinder. Don´t want to make long high rpm run on ground because insufficient cooling.
If you want I can make another video with temperatures on some cylinders? Have gun with Celsius and F switch ...

Maxam

My Feedback: (62)

About the APS pump. Mount the pump next to and level with the bottom of the tank. This will prevent pump leaks. I know this sounds strange but it is true. LiFe of 2500 Mahr should be plenty for the ignition. Yes these engines are economical, but then again I rarely hit full throttle. It would be interesting to see how even the cylinder temps are at idle, mid throttle and full. I never allow my engines to run above 210 F. If Redline two stroke oil is available in your country, it is the best and your engine will last seemingly forever. The go cart guys say Redline allows two years racing rather than one without engine rebuilds and they run their engines hard. -Tom

Dzordzik

You think place pump around bottom side of fuel tank? Or under fuel level? I plan use 2S A123 2500 or 2S LiIon. Have tested both? I have new (red) ignition.
If I remember correct, on idle was head temperatures around 80 celsius and with some mid and high rpm´s go higher up to 90-98 celsius. I think it is ok on ground because in the air temps will go down. Have plan to use temperature telemetry sensor with log feature.
No, redline I cannot buy in Czech Republic but I think Valvoline is very good and I have good reference for this oil from engine constructer from Valach Motors (big radial engines), this is Czech company too.
Want to ask you, how often and how much and where exactly you apply oil for valves?

Maxam

My Feedback: (62)

I only have the old black ignition modules so I use a voltage regulator. I place the pump beside the fuel tank even with the bottom. When the tank is full the fuel level is above the pump. Your temps sound fine. A good test is run the engine up to full throttle for about ten seconds and then shut down completely and immediately measure temps on all cylinders. Oh I know all about Valach. I had a chance to buy the VRM 800 for $5000.00 but I did not have the money at the time.