RE: MOKI RADIAL Care and Maintenence
 

Here is a picture, looks sweet right?

//Taygher

RE: MOKI RADIAL Care and Maintenence
 

So, it's time for a little more intensive maintenance on my 150. Scott Prossen was checking out my engine at a recent event in Owatonna, MN, and he was laughing at how ridiculously filthy my engine had become.

When I would lube the rockers and push rod ends before each day of flying, I was basically saturating everything with light machine oil, and I was even saturating the valves. Apparently, this is not such a good thing and I was only supposed to be applying a tiny bit of oil to the little "oiler holes" on each of the rockers. Moreover, and prior to using machine oil, I was spraying white lithium grease in and around the rockers and valves... an even bigger mess!

Well after talking with Scott, he suggested that some carb cleaner and high-pressure air could be used to clean-up the valve train (and the engine in general). Honestly, his suggestion was to pull the engine and have Goetz and his crew get it cleaned and tuned up for me. But, since I plan to attend and fly in the Indiana Warbird Campaign this coming weekend, I thought I might be try to clean up the engine myself before I pull it and ship it off for a thorough evaluation.

So, I'll tell you my plan, and hopefully if I'm way off base someone will chime-in and stop me before I get started.

I picked up a product called Sea Foam Deep Creep. One cylinder at a time, I was going to remove the plug and push rods, saturate the valves and rockers with the Deep Creep, and then repeatedly work the valves up and down to fully free them up and loosen any carbon deposits. Afterwards, I will use compressed air to blow the excess fluid and dirt from around and out of the cylinder.

After all is clean, I would then oil the rockers using the oiler holes only, as well as a tiny aount on each push rod end.

Does this sound reasonable?

Thanks in advance for the feedback.

Noah

Here is a photo of the Sea Foam product:

RE: MOKI RADIAL Care and Maintenence
 

Friends,
something new arrived today in my office. :)

This is the brand new MOKI 180, Serial No 18002.
The second engine in Germany. Airworld (the distributor in europe) had recieved 2 pre-series engines. One they do test on their own, and due to my good relationship to Airworld I am the one to test fly the second engine. No, not for free, it is regularly paid. I am afraid my poor budget has to suffer this blow ;)[:@]

Before everybody rushes to get one, the official market introduction is planned for November.

The 180 is made of 2 already existing components: it uses the 150 crankcase and -shaft, and the cylinder / head / piston assemblies from the new 250 7-cylinder engine. Clever idea!
Thus making it an engine with a short stroke to diameter ratio (same stroke as a 150, but bigger piston), giving it20 percent more displacemet than a 150, not being heavier or bigger (!!)
RPMs are supposed to be 300+ above a 150, depending on the prop. The Airworld engine has about 10 hours on the clock now, mine will fly within the next 14 days ( in my Ziroli Hellcat).

To be continued :)

RE: MOKI RADIAL Care and Maintenence
 

We will call Airworld today !

RE: MOKI RADIAL Care and Maintenence
 

Hey Detlef, I wonder if the 180 will need turbulating! I am sure you would come up with one if needed. -Tom

RE: MOKI RADIAL Care and Maintenence
 

Tom,
I promised to test the engine out of the box. At least at first.
Advantage of this way is to see what todays state-of-the-art is with Moki.

But if the engine behaves like I expect it to (it will be not far away from the behaviour of the 150 I guess), I know what to do, of course http://www.rcuniverse.com/forum/js/f...wink_smile.gif

The mixture distributioneffect is mainly based on the chosen carb and the design ( and size) of the crankcase. The 215 / 250 behave the same, as the have those components in common.
So the idea that the 150 and 180 are quite comparable in this pointis no risky guessing http://www.rcuniverse.com/forum/js/f...wink_smile.gif

But we will see what the engine tells us.

RE: MOKI RADIAL Care and Maintenence
 

<div>Last flight I noticed a slight change in sound on my Moki 250. I landed at once to inspect. The engine made a different sound while accelerating from idle to midrange. After a while I noticed that 1 cylinder was "shaking" when accelerating the engine.</div><div></div><div>I found that 2 bolts that hold the cylinder are broken! [:o]</div><div></div><div>This engine has made 35 flights and was purchased this winter. I use an APS fuel pump and Kunkels turbulator. Until this mishap the engine has run fine, and the throttle response has been fantastic.</div><div></div><div>Has anybody had the same problem? Any ideas what could have caused this? Tomorrow I will contact Airworld and discuss this.</div><div></div><div>Thanks,</div><div>Clarence Carlsson, Sweden</div><div>PS: This thread is fantastic-I have learned a lot about these engines and it has convinced me in buying this engine. Thanks all who have contributed.</div><div>[youtube]http://www.youtube.com/watch?v=g-qMLvoIWME[/youtube]</div><div id="myEventWatcherDiv" style="display:none;"></div>

RE: MOKI RADIAL Care and Maintenence
 

Do you guys that fly the Moki radials use anti seize paste on the spark plug threads? I'm thinking this may be a good idea on my 250.

RE: MOKI RADIAL Care and Maintenence
 

to luckyflyer : I use cupper grease
to clarence : never see or heart from this problem before, i can only imagine that the two bolts where not tightened enough, after running in it's better to check all the bolts

RE: MOKI RADIAL Care and Maintenence
 

It is hard to really see the broken shank of the bolt, but it appears there is corrosion shown in the fracture. Can you take a photo closer so I can see the fracture as straight on as possible? If corrosion is present, this could have started from a nick or crack upon assembly. The break looks similar to propagation of a crack caused by a stress riser. A closer look could determine this. This would explain why you do not hear of this happening on this thread.

RE: MOKI RADIAL Care and Maintenence
 

Anti-seize is always a good idea when installing steel threaded items into aluminum. This will prevent galling. Okay, you know I can not help myself. I want to explain galling. Galling occurs when two mating metal surfaces come into contact and transfer particles, or dissimilar metals come in contact and cause corrosion. These particles cause a seizing (tighten) of the two mating parts, in this case threads lock up.

The best prevention is anti-seize. It is also worth mentioning anti-seize is not a bad idea in any threaded installation.

RE: MOKI RADIAL Care and Maintenence
 

Gentlemen,

This question concerns causing case stress by using washers or shims to adjust the right and downthrust of the Moki 250 on an airframe.
Current build is an Airworld Gee Bee R3. The fuse already has offset and right thrust built in @ 2 degrees right.
Up/down is at neutral. Airworld recommendations call for 3 degrees right and 1 degree down.
My calculatons call for shimming .067 (right and down) or about the thickness of 1 washer to acheive the above.
A single washer placed behind the upper left mount hole would thrust the engine correctly.

Question: Is the engine mount ring designed to accept washers (shims) without placing undue stress on the case????
Anyone know of a better way to acheive the desired thrust.

Keep those posts coming,
Thanks,
Jaketab

RE: MOKI RADIAL Care and Maintenence
 

I just installed a new set of plugs earlier this week. One of the plugs offered a small amount of resistence for the first three or four turns ( would not spin out freely with thumb anf finger had to leave the socket on it ). I had some anti sieze compound in the tool box from when I worked on car motors so I very sparingly applied some to the new plugs. I will most likely put a couple of flights on her tomorrow and will pull a couple of the plugs to see how it effects their removal. I will let you know how it works out.

RE: MOKI RADIAL Care and Maintenence
 

Aloha Warbirdrcer, All,
Air show went great, now I'm about resolving my #3 cold cylinder on my Moki 150.

I've secured thermocouples to all 5 cylinders.
In any case cylinder #3 is running cold. I have my timing light set up so I know #3 ignition is firing.
As you can see from the attached plot, #3 is cold ~ 93F vs about 217- 227 for the other cylinders- (CH0 is Cyl #1, CH1 is Cyl #2, CH 2 is Cyl #3... (free software))
Higher temp ranges were when I was leaning the mixtures. Nominally 3700 RPM high, 940-980 RPM idle

I've pulled the intake tube for #3, easier than I thought, the crush washer is at the tube to sylinder head interface.

Question:
Is there a seal/compound that is supposed to go at the tube to crankcase interface?- it's a close tolerance slip fit, but I could see no seal of anykind- I'm thinking teflon tape or teflon grease or something of the sort. (No smaller dia crush washer that I can see in the case) Any recommendation?

My first experiment will be with a .010 dia hole in theintake tube located at the lowest point of the bend in the intake tube. More specifics, pictures and details as I get results.
Mahalo,
Mark

RE: MOKI RADIAL Care and Maintenence
 

Aloha All,
Never mind on the question- there is a o-ring on the in side of the case bore. (Better light this morning).
Does look like teflon or lithium grease used to lubricate the tube, o-ring and socket.
Let the experimentation begin!
Mark

RE: MOKI RADIAL Care and Maintenence
 

Mark,

Excellent thermal data. I am amazed at the consistancy of temperatrue between cylinders. It appears that #3 is not firing at all. Can I assume that you are using a 50:1 synthetic mixture? If not, that may well be your problem. If so, there are other isuues besides fuel mixture.

Also, do you happen to know your final needle settings?

RE: MOKI RADIAL Care and Maintenence
 

Aloha Bob,
Running Castrol 927 Sythetic at 50:1 (marine gas no ethanol)
Needle settings at High: 1-7/8 from closed Low ~ 15/16 from closed.

Have had some success with the bleed air. working to put it into a presentable format. I seem to be able to get #3 working as some RPMs, but as expected not all. And eventually the #3 fouls out.
One other interesting observation so far- with the small hole in the #3 intake tube, after a run there is black oily drips coming out. Without the hole that obviously ends up in #3 cylinder.

My experimentation is a little delayed- I had purchased som AN900-6 crush washers, but it looks like should have been AN900-5s, 6s too big. Pleasantly removing and reinstalling the intake tube is wasy, even with engine installed on plane. (Nice design!).

Mark

RE: MOKI RADIAL Care and Maintenence
 

Mark,

Thanks for the needle valve data. I'm trying to develop a database on 250 & 150 engines. Every engine is different, but they should be somewhat similar based on altitude. I forgot to ask for prop size.

I would like to understand your themal data a bit better. I assume that it is from a ground test run. Can you provide a run sequence? The long tail off looks like the engine was shut down and allowed to cool, but I'm guessing.

Thanks again,

RE: MOKI RADIAL Care and Maintenence
 

Jason,

I don't know if my printer settings are set incorrectly but this does not match my new Moki 250 mounting plate. If I align the 1 o'clock position hole, the other two holes are too far in. Any ideas?

Tim

RE: MOKI RADIAL Care and Maintenence
 

Tim,

The file I posted was a scan of the dimensions for reference. I just tried to print the scan and had the same issue, so something changed when I scanned it for upload. Send me a e-mail @ [email protected] and I will send you the .DWG file, no problem. I created the file using Draftsight. I use it for all my CAD design and it is free to download. You can print 1:1 using custom setting, so it will be scaled properly for you. Talk to you soon, Thanks and take care.

Jason

RE: MOKI RADIAL Care and Maintenence
 

Thanks for the quick response Jason. I just downloaded Draftsight and you can send the .dwg file to [email protected]
Thanks for your help!
Tim

RE: MOKI RADIAL Care and Maintenence
 

Tim,

No problem, glad I could help. I sent you two files, one with the dimensions and one without. If you need any help printing the file in Draftsight, please don't hesitate to ask. Take care and all the best.

Jason

RE: MOKI RADIAL Care and Maintenence
 

Hi,

Seems like my Moki 250 is running a bit hot and it is going a little rough.

Anyone out there with a 1:1 drawing of a template for cylinderbaffling so I do not have to try making my own?

RE: MOKI RADIAL Care and Maintenence
 

This is all a bunch of horse apples!

A 59-page thread full of well-intended discussion and suggestions on how to improve an engine brand with an ABYSMAL performance and reliability record.

I would like to see an accounting of all Moki radials for the last several years. I'll bet 90% of them either: A) hardly ever fly, or B) have failed in some way, causing expensive crashes.

Turbulators? After-market fuel pumps? Individual thermo-couples? All kinds of parts that fall off when they shouldn't?

Radials have been around for >100 years. Moki clearly hasn't learned how to make the technology work on this scale.

Granted, the sound is seductive, and some guys, like the starter of this thread, have it figured out . They're awesome to watch!

But I'm not that smart. Modeling is my HOBBY, and when I spent $4,000 on a motor, I expected it to WORK, like all the other expensive motors on the market.

Like the motor in my car, which cost about the same.

Is that too much to ask?

When somebody comes out with a $4,000 radial that runs reliably, then I'll buy it.


Signed:


mt
(bitter loser of a beautiful Focke-wulf whose Moki 215 ran great on the ground, but puked over a large clump of trees.)

RE: MOKI RADIAL Care and Maintenence
 

Horse apples! That’s an interesting turn of phrase, not sure what it means though.

Yes this thread is rambling and sometime meaningless, but that’s the nature of folks, many of us spend time searching for problems just so we can find a remedy for them instead of getting on with the job of just flying!

I have an eight year old 215 in my 3W Yak54, it has had literally gallons of fuel through it, admittedly I did have some initial fuel feed problems resulting in many dead stick landings. I was probably one of the first flyers to fit an external fuel pump, since then it has never failed.

Ninety nine percent of the problems with these engines is inadequate cooling it’s not a case of supplying the engine with cooling air it’s getting rid of it once it has done its job. This problem is as a result of the type of model they are usually fitted to. I am flying a Scalewings La7, Moki 250 right now exhibiting just these symptoms. So I am afraid your opinion of these motors is just not true, set up correctly out of the box they will run for ever!

m