LRFitch

Guys, thanks for the info and link. I think Vogelsang is likely my best option.

Larry Fitch

x0xorena

My Feedback: (2)

RichardGee

My Feedback: (156)

Gents, the answers to my questions are probably somewhere within these 163 pages, so I apologize in advance if these questions have already been answered:

Difference in weight between the 215 and 250? I find conflicting info online.
Much difference in power or will they both spin the same props, just with slightly different top rpms?
Is the new Blue Box Moki ignition an improvement over the old black cylindrical version?
Is it possible to run these reliably on the integral fuel pump, providing the pump line is cleaned every few flights?

Thank you!

Remaking

My Feedback: (15)

I have had 3 of each so will take a stab:
Not sure of the exact weight but they are close.
The 250 is noticably louder, makes more power but yes they spin the same props.
The blue ignition box is WAY better than the black Top Hat. I've had 3 of 4 black ignitions fail on me. When replacing with the blue its a whole new engine, and you can run any battery.
I run an electric pump on all my Moki's. Turn on the pump and 3-4 flips and it starts. Trying to pull prime with the Piston pump and choke takes forever. Sometimes 20-30 flips. Plus the engine runs more evenly without having to change mixtures with temps.

msouers

Hi Greg,

Where did you get your bombs and how did you attach them?

Mark

RichardGee

My Feedback: (156)

GREAT Info. THANKS MUCH

IFLYBVM2

My Feedback: (360)

Hi Richard-
I also have several Mokis-both 250 and 215. Power wise, I have a strong running 215 that turns within a couple hundred of the 250. It depends on the engine if course, but doesn't seem to be that much difference between them.
Weight wise, the 215 should be slightly heavier, as the 250 is a bored out version of the 250 with identical external dimensions, so far as I can tell.
Over the years I have surveyed at least 50 modelers about whether or not they use an external pump: I have found almost an exact 50/50 split. Some guys, including some high time Top Gun caliber pilots I surveyed, have never used them and their Mokis run flawlessly. Important to have the tank position at least even or slightly above the carb if you don't run the pump though. I personally subscribe to this line of thought-if you consider the addition of the pump itself, it's battery and switch, you are eliminating 2 or 3 possible choke points in your setup. Keep it simple...
On the other hand, the other half of guys would not think of running without a pump. At the end if the day, I guess there are no wrong or right answers here-just what you feel comfortable with. I did speak to at least 3 guys who had pump failures-luckily all 3 on the ground.
Just my opinion-your actual mileage msy vary, as they say.
​​​​​​​ Regards-Mike O.

RichardGee

My Feedback: (156)

Mike O.
Thanks for your response. I too ran a Moki 250 in a CARF P-47 w/o a pump. I was very vigilant to keep the clear pump tube clean of grease and never had a fuel delivery problem as far as I could tell.
I never measured cylinder temperatures, but the engine always started easily and ran well with plenty of power.

Greg Wright

My Feedback: (6)

Hi Mark.
I got my Bombs from Ziroli and used the BVM bomb releases to hold them in place.
If i ever decide to make them droppable i will just have to run some airlines to the releases and add a small airtank and valve to make them work.

Papasal

Good morning all, Papa Sal here from Reno, NV. Thank you all for this excellent fourm! My question is : do you think a Moki 180 will have enough power to fly a33%Yak 55M @ 28 lbs. Or would the 250 be better? Thank you all for your inputs.
Papa Sal

RichardGee

My Feedback: (156)

Absolutely! A 250 would be serious overkill in power and weight. A 33% IMAC plane is a 100cc aerobatic aircraft. A Moki 150, 180 or Evolution 160 are the approximate equivalents of a 100cc two stroke as far as HP. A 250 radial weighs twice what a 100cc twin weighs and spins twice the propeller. Much more appropriate for a 40% aerobat.

BobH

My Feedback: (2)

A lot depends on the plane's weight. If it's light enough the 180 could work. The 215 would be better with more margin of error and the 250 should leave no doubt about performance.

GeorgiaFlyer

I agree with RichardGee, the 180 would be plenty for that size plane. search youtube there are some videos out there of others using the 150 and 180 on that size Yak.
Cheers!

heres a link to one

Papasal

AWESOME! Thanks Gents. Just as I thought. Thanks for all the input. My dream just may come true. BTW GeorgiaFlyer GREAT VIDEO! It warmed my heart to see that yak pull out of a hover with power to spare!

Big1Birdy

Hi All
I have a Moki S180 which I bought about 2 years ago, after initial test runs I put the engine away for the winter. When I got it out again the following year I could not get it to run properly. As I live in the UK I sent it back to Airworld in Germany, it was returned to me and they said that they had changed the carburettor! However I still can not get it to run properly.
The engine will start and it picks up speed for a few seconds and then dies back to a poor idle and then stops. What ever I do I cannot get it to run. I am using Stilh premix 50:1 fuel and the engine is a new with no modifications. I have read this forum right from start to finish but nothing I have read so far has helped me. I would really welcome some advice or suggestions from "seasoned" Moki owners.

Many thanks John

RichardGee

My Feedback: (156)

The problem DOES sound like it is related to fuel delivery. I assume you are NOT using an auxiliary fuel pump? With a new carburetor, the pump diaphragm is no longer the most likely suspect... I would suspect the air pump located at the front of the engine, driven off the cam. I am assuming the pump is frozen and not providing the pressure pulses required to activate the carburetor diaphragm. IF you ARE using an electric fuel pump, then my theory is ALL WET
If you add an electric pump and the engine again runs perfect, the problem is the air pump unit.

Big1Birdy

Hi Richard, thanks for you reply. I too believe that it could be a fuel delivery problem, I have tried testing the pump by getting it to suck water up and down a long piece of tubing, which it does. I have also tried placing the tank up to 5 feet above the engine, without success. Other than buying an expensive pump I don't know how to test it further.

Walter_Mitty

John ,
where are you ??
I'm 9 miles west of Cambridge , Pm me your numbers , and we can chat
Cheers
Phil

snauwaertj

Hello,
I just bought a used moki 100 flat twin, there don't seem to be many out there and there is very little to find about these flat twins.
Anyone here got some experience with these?
I would like to use it on a 2m40 FW190 A8. Biela makes a nice 24x10 3 blade scale prop and I was wondering if this would be a good choice for this engine.
Is an electric feulpump usefull on this engine?

Kind regards
Johan

Detlef Kunkel

John,
a simple quick test could bring some answers. Blow with all power that your lung has into the vent tube of your tank and close it. A human being can achive something like 0,2 bar of pressure with this.
When your enginge runs great (maybe some high needle adjustment due to the new pressure) with a fuel pressure of 0,2 bar, your pump system has a failure. then we can go on.

Dont unbolt all the engine before you get closer to the problem. Report when you did it.

Big1Birdy

Detlef,
Thank you for your suggestion, it has given me an idea whether I could connect my compressor to my tank vent and set it at about 4psi or 0.3bar to test the the pump. I was hoping that lifting the tank would have the same effect, I will give it a try.
Many thanks for your help.
John

Big1Birdy

Detlef
I got the engine running today by pressurising my tank to 5psi using my compressor.
I also have spoken to Phil Elner who has been very helpful and has offered to send me an electric fuel pump for me to try. So hopefully this will sort the problem, but I still don't understand why the engine's own fuel pump does not function correctly as it should.
Kind regards and thank you for your help.
John

Lletisso

Hello, I have a Moki 100bvt for four years and is a wonderfull engine! I run it with a 26 10 fiala propeller anb it takes 5400rpm. Also a fiala 3 blade 24 10.
I never instal it a fuell pump, and in four years never had an insue. I have mesured 15,5 kg of static trust. I run it with a 2 in 1 exaust sistem.
Here is mine:

GeorgiaFlyer

wow that really sound good!

snauwaertj

Sounds great indeed!
Do you dive that Corsair full throttle with the 26x10 2blade?
I was considering to put a CFK falcon 26x11 on mine, they are very light and people told me they spin a few 100 RPM more than other brands that are the same size.