wphilb

My Feedback: (10)

I pulled mine out and checked, it ran fine through an M5 with .8mm pitch. It also went all the way through a 12-24 inch checker but with more slop so I guess one could use that size in a pinch with some high temp thread sealer.

This was off my low SN Moki 150, assume your higher number SN should be the same.

Whit

bcrc

My Feedback: (19)

I have a Moki 150 that sits in front of a firewall and is 100% exposed. In the past I used 1" standoffs to give the carb some breathing room ( a little over 1"). Now I have added a Kunkel turbulator to solve the #3 and #4 cylinder problem. Temporarily, I have 3" standoffs. I would like the standoffs to be as short as possible. My question is this: How much room should I have between the back of the carb and the firewall. I have always heard you should leave 1". I have run 1/2" on a 2-cycle gas engine with no problem, and I have seen guys have it so close that the choke can barely open - I don't know what kind of luck they had.
Has anyone experimented with this distance? If so, please let me know your findings.
Thanks,
Brian
BCRC

IFLYBVM2

My Feedback: (360)

HI Guys-Where can I find a piece of the clear tubing that runs from front of engine to carb on the Moki 150 ? Mine needs replacing.
Thanks-Mike Oberst

reyn3545

It's 3mm festo tubing.. you can order it from most hobby sites that carry turbine accessories... BVM, TroyBuilt, etc..

reyn3545

quick question on the Moki exhaust ring.....

I took the cowl off tonight to start looking at the smoke system, and noticed that apparently there are nylon fittings between the exhaust tubes leaving the cylinder and the exhaust ring. These fitting (rings) have melted somewhat and started oozing out the top of the fitting that holds the exhaust tube to the exhaust ring. Is that normal? I was surprised that there was ever anything nylon in that area to start with!

butlern

My Feedback: (15)

those are teflon seals, yeah?

reyn3545

Yes, I guess it's probably teflon, not nylon.

RichardGee

My Feedback: (156)

This is "normal" due to the HOT running nature of Moki radials. IMHO, they would have been well-advised to substitute a soft copper washer instead of teflon, etc. These DO wear out and require replacement periodically if you wish to keep your exhaust system sealed up tight. A "leaky" exhaust system will not necessary affect your engine's running characteristics, btw.

reyn3545

OK.. thanks. I've tightened the nuts down a time or two, and I guess that and the heat is causing them to deform. I'll just keep an eye on things and see where it goes from here. So far, I've got maybe 20 flights or so on the motor, it's running like a top.

mogman

Mine have melted and oozed out a bit on my 400. Every so often I check the gland nuts for tightness(when cold!) So far no leaks.

357 magnum

I have just purchased a moki 180 with the new processor ignition and it dropped its banana about 4 mins into the first run just wondering if any one else has had this problem I have no problem the dealer just asked me to send it back but just a little concerned

reyn3545

I got the smoke hooked up today... works great, but what a mess that stuff makes! Something tells me I may be taking this stuff off after a few flights. I'll dial the smoke down a bit so it's not pumping so much juice through the system. If that doesn't help with the nasty stuff on the fuse, I'm going to quit smoking! I will admit, this thing does seem to put out a lot more smoke than a 2-cylinder gas motor.

ram3500-RCU

My Feedback: (221)

I would simply readjust your Solo prop. Adjust the pitch up until you get 3800 RPM on the ground. It will unload in the air to a safe margin, and you will have tons of pulling power. This engine makes it's power at lower RPMs..

affas

I have done some more baffling in my large Texan / Moki 250 now. What temprange is preferred when I do measure after landing? (Celsius)

bcrc

My Feedback: (19)

Hello:
I have an early Moki 150 that I have been running for about 5 years (maybe more - I can't remember when I got it). I've been following this thread since its inception.

Two or three years ago, I took the front housing off to check the grease. When I saw how "cheezy" the air pump was, I promptly got rid of it and got an electric pump from Gotz and have been using it ever since, with good results.

A couple of years ago, when all the info came out about the #3 and #4 cylinders on the 150 not running, I checked mine out and, sure enough, the #3 rarely ran and #4 about half the time.

So, this summer, I decided I was going to fix it. Note that through all these trials and tribulations, I was running 50:1 Amzoil, and each step of the way we were varying the carb settings as needed (as has been noted many times in this thread, the leaner the better). A friend of mine and I are good with carbs, so we know what we are doing.

First, I switched to the Denso U20M-U plugs and that didn't help.

So, I bought a Kunkel turbulator from Gotz. That helped a little, but #3 only worked some of the time and #4 most of the time. Then I rotated the carb 180 degrees, and with the turbulator on, it worked a lot better. We could sometimes get all cylinders to run all the time and at all throttle positions, and in the air. The engine didn't sound that much different when running on all 5, but there was a big (probably a 25%!) increase in power. Then, just we we would think we had it licked, the next day, #3 wouldn't run. We tried removing the turbulator, leaving the carb upside down, and it didn't work as well. I also noted that I could rotate the carb mount to each of 5 positions. Thus, with 5 positions of the carb mount, 2 positions of the carb at each position of the carb mount, and with/without the turbulator at each one, I had 20 ways to try to fix it. Also, Gotz told me that if the turbulator didn't fix it right away, to try rotating the vanes about 45 degrees. So, now we had 40 possibilities! Needless to say, I didn't try all 40 !!! However, we did try about 8. It ended up that the best position was: turbulator on (vanes in original position), carb mount in original position, carb upside down (rotated 180 degrees). But, as I said before - we could get it running like a champ, and the next day #3 and/or #4 would cut out.

So, at this point it is clear, that even with the turbulator/etc, it is borderline. What i am wondering is this: back at about page 65 of this thread BIGDAMMODELS and GOODNMW were working on their own "turbulator" vanes deeper down in the intake tube. DID ANY OF THESE MODS WORK???? Does anyone have anything that worked solidly???

I like the idea of the new Rainbow-tronics ignition. First of all, it needs a stronger spark, and it is terrible design to put the coils inside the engine with all the heat/oil/etc. I am probably going to get one, but that doesn't really fix the problem that different cylinders are getting different mixtures, so I would like to fix that the best I can before getting the new ignition. Does anyone have experience with the Rainbow ignition?

Thanks,
Brian

CH Ignitions

My Feedback: (11)

Hello,
Would you be willing to send that engine to me and install my ignition on it and test it?
Will not cost you anything, just shipping back and forth.

Alf, same offer stands for you.

Thanks
Adrian

reyn3545

I put a Rainbow ignition on my 150 about 2 months ago, and have never looked back since. It starts easily, runs flawlessly at any speed,

I was having the same problems as you, but with a newer model motor (BTW, it's a RCS, but they are the same motor). No value in using the turbulator, so I skipped that step. I worked with Goetz on a couple of phone calls, trying to get the motor as lean as possible to run well on all 5 cylinders. I tried rotating the carb, went to the hotter plugs, etc..

When I switched over to the Rainbow Tronics system, it did run like crap at first... but I quickly figured out that I had swapped the #4 and #5 plug wires. After that little snafu was resolved, it's ran like a top ever since.

I think, unfortunately, that the quality of the original ignition system varies quite a bit. Some people get a good one and never experience a problem, and some people get a flaky one and never quite get the issues resolved. I hate the idea of spending $500+ to get a "new" motor to run properly, but I hate worse not spending the money and having a plane that runs poorly.

I also bought a fuel pump, but haven't decided to put it on yet. I suspect some day I'll either get around to it or wish I did... I'm not crazy about that piston pump either. Looks like a neat idea on the surface, but if there's no way to keep the gunk out of the air tubing, it's a dead stick looking for a place to happen.

heinzulrich

Well, here I thought had all my problems solved by installing three pumps in three different air craft, one had a 215 other had 250 and my waco has the 400 in it, And yes, you guest it all , #three cylinders are not working. The 250 & 400 are 1 year old engine and the 215 about three.
Here is my question, has any one rotated the engine orientation and observed if the #3 cylinder in the new location is doing the same thing or if the problem is still in the same location...
Heinz

reyn3545

I don't think the Moki 400 is designed to run at your latitude.. I think you should sell it (cheap) to me!

Sorry to hear about your experience... I had heard that the pumps helped quite a bit, particularly on the smaller engines.

Der Goetz

My Feedback: (9)

Hello everyone,

I never post here for which I apologize, I should come here more often and chime in with my 2 cents.
Anyone of you can call me or email me at [email protected] should you have any Moki questions that you would like to discuss. It does not matter whether you purchased from me or not, we are all plain RC enthusiasts, working together to make things work. Should I NOT have the answer for you I will do my research and get them to you. No made up stories or BS here for the sake of "being a know-it-all".

As for our Rainbow ignition, yes, I do have it in stock and so far it has beaten every single 150 into submission. We had two motors here, old generation ones that were sold before I opened shop, and they were dead on #3. Not borderline but dead. And I tried all the clean and dirty tricks in the book. What really brought it home was the fact that you were able to rotate the radial on the test bed and the problem would stay at 7 o'clock, no matter what cylinder was in that position at the time. Long story short, that was what made me talk to my friends in Germany, Detlef Kunkel and Uwe at Rainbow amongst them and Uwe came through for us with his amazing ignition. And when you think that his Moki ignition is wonderful you should really take a close look at his 2-stroke ignitions for your DA's and 3Ws as well as his glow modules. I am running his ignitions on all of my DAs and 3Ws at 3s LiFe, no more 6Volt ceiling, a spark like an ox, LED pattern coded information/status read out and and and.


Long story short, the Rainbow ignition has come through every single time for us, my customers run it on old 150s in order to make them run on all 5, they run them on the current 180s to get the extra power, the extra convenience, the extra features.

You can always write me a [email protected] or try calling me at 919 533 6275
Emails are best as I manage to do 70 to 100 Emails a day, the phone is my angry step child
And I promise to come here more often. Or just send me an email should you want me to chime in on the forum, here in Scott's thread.

Best regards
Götz

heinzulrich

Nice try you get an "A" for trying..
Any how, I was wondering if the "Valachmotors are having the same problems???????
Just a thought... or are they made by the same company.....

reyn3545

I do have a quick question about starting these motors... I assume that in order to avoid useless flips, you should orient the motor until the #1 cylinder is about to fire, and flip the prop through the point that it does fire. Doing that, you should at least have a 50% chance that you will flip through the ignition stroke (not the exhaust stroke) for the #1 cylinder.

I'm assuming that the crank has only 1 timing point for the ignition pick-up, and all the others are based on timing from that.... is that correct?

Right now, I just keep flipping until it starts, but it seems that there is one prop position that works most of the time... I'm assuming that this is where the crank goes through the #1 ignition point.

reyn3545

Thanks.. I'm way too cheap to buy one for myself, but those are great sounding powerful motors!

butlern

My Feedback: (15)

Rainbow ignition did not do the trick for me... I have a September 2009 version of the 150cc.

Before the Rainbow ignition, I struggled a lot with this motor dropping cylinder 3. Eventually I just started leaning the motor hard, leaned to get best performance on all 5 cylinders at higher rpm, and it eventually ran well wide open. But, my issues persist and are related to lower rpm/idle. I tried Denso plugs, too, no love. Based on feedback here I installed the new Rainbow ignition (did not remove the original set-up, just held all plug wires out of the way with zip-ties) and the motor runs worse than ever.

I must say it's been so hot and I have so little free time that I have not spent much time trying to figure out why the motor runs so poorly on the Rainbow ignition, but I'm tempted to pull it all out and go back to my original stock set-up. I was hoping that I simply mis-installed two (or more) plug leads (firing out of sequence), but that's not the problem.

Running the new Rainbow on 3 cell LiPo 2200 mAh battery, by the way.

A bit frustrating... I have not flown the plane since (about 2 months). It's all collecting dust.

reyn3545

If your problem is at lower speeds, have you checked the pressure line going from the front of the engine to the rear? It may not be pulling enough pressure/vacuum to operate the fuel pump on the carb. You've probably checked and eliminated this as a possibility, but I thought I'd make sure.