flyn2high

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I purchased a Moki 5 Cylinder 250cc Radial Several years ago for a scratch built Hellcat project. I discovered that my ignition module was defective two days ago. I replaced it with one out of an older Stearman of mine that had a 215cc radial.

The Hellcat runs great now. However, the Stearman is short an ignition module.

I know that the new Moki radials use a high voltage module that gives a stronger spark to help in rich fuel/oil mixtures and many have upgraded. I would be interested in purchasing the original top hat design ignition module unit if it is in good working order.

Please send me a private message and let me know how much you want for the unit.

reyn3545

Lou,

The new modules don't really do anything to deliver a stronger spark to the motor. The new modules still use the old coils embedded in the back of the motor, and it's the coils that power the spark plugs.

The new module (from what I understand) is updated to accept a wider range of unregulated batteries, and it does a better job of advancing the timing for engine starts. It might also have updated LED's like the RainbowTronics unit, to tell you when you are powered up, when you have over-revved, when you have low voltage, etc.... but, since the system still uses the original coils, it doesn't provide any additional energy to the plugs. According to Goetz, the new module is a direct swap-out for the top-hat modules.

flyn2high

My Feedback: (2)

Thanks reyn3545:

Goetz was offering me a High Voltage Ignition Module that is supposed to be able to provide a strong spark in higher levels of oil and gas. I was assuming it was the newer Moki Module. Do you think it is a better option over the new flat pack moki module? As you said the coils are in the engine and that will not change so the spark I get will be dependant on the internal coils.

Right now after tuning the carburetor and going to a 50:1 mix it is running very nice on all cylinders. i'm not sure i need to go to an exotic ignition the way it is running now. There is still black oil coming out of the exhaust but it only had about 3/4 of a gallon run through. My Stearman did that for quite a while before the exhaust cleaned up. I was running 40:1 oil on the stearman and had to clean the plugs every third flight.

reyn3545

If you've got it running reliably on 5 cylinders, even if it is idling on 4, I don't think you're going to see improved performance by trying anything else. I've got only a gallon or so through my 250, running 50:1 red line, and it's still producing its share of black gunk. Red Line will always produce residue, but it's about the best synthetic that I've seen for preventing carbon buildup inside the head.

I have a fuel pump and turbulator on mine... I've always used fuel pumps on these motors, and the turbulator was on this motor when I bought it. I'm not sure if I really need either, but Goetz recommended them, and the turbulator did push the carb needles to a better location on my plane. It's running great now, although even with the turbulator, it will drop a cylinder if I let it idle for a while. It comes back when the motor revs up, so I'm not too concerned.

wphilb

My Feedback: (10)

Lou,

Nice to hear from / about you, I miss flying with you and Roy etc.

I think Gotz was talking about the Rainbow Troincs upgrade ignition, not a newer Moki factory unit. You might want to ask him about that. I am running the RT upgrades on both my engines and like them, especially ease of starting. You do have to either remove the old coils from the back of the engine, or just cut off the old spark leads close to the engine mount but I found the upgrade easy to do or Gotz has a guy who can do it for you. Both my 150s are relatively early serial number engines and benefit from the stronger spark of the RT unit.

Whit

reyn3545

I put the Rainbow Tronics unit on an older 150 that was having issues... cured the problems immediately. And like Wphilb said, it's a very simple install and it does replace the coils inside the motor housing. I hope the new blue coil has some of the intelligence and LED feedback that the RainbowTronics has, and I wish it also replaced the internal coils.. those are really old technology, and if you ever look at them, you'd think it was someone's first soldering job.. maybe it was!

reyn3545

Did RainbowTronics ever expand to other motors, or only the 150?

flyn2high

My Feedback: (2)

Thanks for the great information. Rainbow Troincs ignition is only for the 150/180 right now.

I think I am going to stay with my setup as it is running sweet. I am using a pair of A123 batteries with a Formeco regulator set to 5.95 VDC. I also have the pump installed. I did not plan for and there is no room for a Turbonator. I could not fit the 50 oz dubro tank in but I did manage to fit two 24 oz tanks that are set up so one feeds the other. I think that should be fine.

The video of my first flight and forum build is at http://www.rcuniverse.com/forum/gian...l#post11828625

reyn3545

Thanks for sharing... very nice work on the plane, and it looks like a great flying field also. I used to come up to Holtsville pretty often when I worked for Symbol/Motorola, but not anymore. Now Motorola is selling what's left of Symbol to Zebra Corporation... maybe it will regain some of the spirit it once had.

wphilb

My Feedback: (10)

Lou,

Very nice plane! That's a lot of motor, I see you have it well baffled, how well is it staying cooled?

Whit

wphilb

My Feedback: (10)

I got another five flights on the Telemaster / Moki 150, very pleased. 4800 RPMs on the 28 x 14 temps from 170 F on number 3 to high of 217 on number 1 after shutdown. Was reliable every flight even with long idles during touch and goes, rare misfire but sounds good to my ear.

Two issues, spark plugs were put in by Superman, can't get them loose, I want to check condition and clean if needed, suggestions? Also number 4 cylinders exhaust valve is sticky even though well lubed, how can I free it up again?

Whit

reyn3545

Is it the rocker sticking, the spring, or the valve sticking in the guide? If either of the first 2, replace the rocker, pin and spring. For #3, if you've got a carbon buildup in the head (not likely after so few flights), I would run a few gallons of Red Line synthetic oil and see if it improves. I've used it in old 2-stroke gas motors that had carboned up inside the combustion area... after a gallon or so, the cylinder and top of the piston look like new. Red Line will always leave just a little residue out the exhaust pipe, but it seems like a fair trade-off to me.

wphilb

My Feedback: (10)

Not sure, if I remove the rod and move everything by hand, the rocker moves just fine but when you manually press the rocker against the valve and spring it's significantly harder than the others. I have squirted some of the TRI Flow lube inside the cylinder while compressing the valve and spring and can get some black gunk out and then it's better for a bit but still stiffer than all the others.

I am running Yamalude 4S oil at 40:1 with 93 octane auto gas, happy to try Red Line can you tell me where to get it? Does it clean the engine or just allow it to burn itself clean? Don't care about exhaust residue, that's what rags are for! lol.

Thanks,

Whit

reyn3545

Red Line is a synthetic lube that is used mostly in racing motorcycles. They have it at most motorcycle shops, or you can find it online. It's the only oil I use anymore in any of my airplane motors, mixed at 50:1. I would guess the the oil allows the motor to burn itself clean... it will take several tanks to work fully. You'll see the same old black gunk coming out of the exhaust that you did when the motor was new. When that gunk turns to just oil residue, your cylinders and valves should be pretty clean.

Here's a link to the oil... it's their 2-stroke racing oil.

http://www.redlineoil.com/product.aspx?pid=19&pcid=16

Jaketab

My Feedback: (2)

Whit,
I had exact same problem. Yamalube at 40/1 may have contributed to a stuck #4 exhaust during the break in process of my 250. Running motor too rich will also stick valves. I only use Stihl Ultra at 50/1 with very good success. Point #4 cylinder straight down, remove plug, open #4 exhaust valve and spray Seafoam motor treatment into the cylinder. The idea is for the penetrant to run down the valve guide tube and fee the valve stem from the gunk. Manually depress the valve open and close to free it up. Give it an overnight soak with a good cleaner.

J Tab

reyn3545

I've heard good things about Seafoam... good luck, and keep us posted.

wphilb

My Feedback: (10)

Ok, I got some Redline on the way, and will get some Seafoam tomorrow and will let you all know how it goes. I'm pondering wether my problems with my first Moki 150 might be oil fouling combined with the inherent issues of the number three cylinder. It ran "OK" for awhile but then even with the new ignition it has issues but it's been run with Yamalube at like 40:1 for at least three gallons, prob more like four and the second one shows valve issues in under two gallons.

So, ah, one more minor problem. Apparently Superman installed the spark plugs on my Moki, how do I get them out? I tried using the supplied "wrench," really a stamped tube of sorts, with a screwdriver as the handle and while I had really decent leverage it would not budge with the amount of force I was willing to use on a spark plug... Any ideas? I was trying with the engine cold, was considering heat, either through running the engine or heating the head with a small torch. Bad idea? It's the nearly the Fourth of July here, I can wait until the fifth and get a ton of explosives cheap....

Whit

nine o nine

My Feedback: (1)

Hi Whit, Get the correct sized "real" socket on a 3/8" drive ratchet handle and give it a short rap with a light hammer. If that doesn't loosen the grip on the plugs.......maybe hire someone who's willing to pay for caused damage. (.) oops, thats a boob, I meant . Mitch

Maxam

My Feedback: (62)

I am happy with redline too. Years ago with my first Moki 150 I was having a bad time with stuck exhaust valves. An oz of seafoam / gallon as well as redline or Amsoil Interceptor oils made stuck valves a thing of the past. -Tom
I have problems with the thread subscriptions. I changed my RCU E-mail but the subscriptions still get sent to the now defunct E-mail. Any suggestions? Thanks.

Remaking

My Feedback: (15)

Want to post my experience with my 215 for those that may have similar issues, and to acknowledge all the help I received from Gotz at Vogelsang.
My motor basically would not idle on all 5 cylinders and shortly after start up would start dropping cylinders and would literally run on 1 cylinder only. If I could force it into the air it would run at half throttle fairly well, enough to fly it around, but would miss badly at full throttle, and then drop cylinders and die if I throttle down below 1/4 throttle. It would of course always quit on landing.
After weeks of trouble shooting with Gotz:
Changed to 50 to 1 Castrol oil and mix
Different prop 33x16
New Denso plugs
Adjusted valves numerous times
Rebuilt carb
Added elec. fuel pump
New fuel lines
None of which did a thing, we decided to try the new blue ignition module, as my 215 had the old black Top Hat style.
I disconnected the old module, laid a piece of foam on top of it to test the new one on, hooked up the new module and connected it to a 7.4v Li-ion battery and flipped her over.
It was like a completely new and transformed engine! The difference was night and day.
It idled down at 940rpm, rev'd up to 4100, never missing a beat! I let it idle for 10 minutes just to listen to it, as I had never heard it idle for longer than 30 seconds!
Fantastic!

Gonzalo38

Interesting info.....

The other day I was exchanging some emails with Gotz and ask him about the new blue ignition. He told me it wouldn't make any difference in the engine compared to the older ignition. Maybe it was that your old ignition was bad ?

Remaking

My Feedback: (15)

Yes, of course the old one was bad.

Operating, but not correctly.

The new one does allow up to a 9v battery and is supposed to supply a hotter spark.

wphilb

My Feedback: (10)

Gotz has been very helpful to me as well, exchanged lots of emails and some phone calls at no cost to me. When possible I get props / plugs etc from him also the new ignition because he has been so generous with his time. He took some time out of flying at a meet to help me with my engine, which btw was not bought from him. I wish more guys in the hobby were like him.

Whit

Remaking

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I agree 100%!

DrScoles

My Feedback: (18)

Just got my second 250, its a bit dusty and grimy. Any contraindications to using brake cleaner on it? Obviously stay away from carb inlet, but other than that???