reyn3545

I made a little progress.. but from reading the threads, it seems like progress might come and go.

I leaned out the low end to about 3/4 turn (maybe a little closer to 1 full turn from closed), that seemed to help. I richened the high needle just to compensate a little, but still haven't ran it up to see how the response is. I have too much prop on this plane right now.. I had a 30x13x3 laying arond that wasn't drilled and I wasn't going to use it on my DA200, so I decided that it would work until the wood prop shows up next week.

Here's a few seconds of pretty smooth idle, with good temps on all exhaust ports!

http://www.youtube.com/watch?v=qpxGVD_IsK4

Maxam

My Feedback: (62)

Reyn, First the turbulator is not usable on the newer 150's. Detlef Kunkle, the inventor of the unit, explained the newer 150's have a modification in the inlet tract making the turbulator ineffective. The leanest setting on the idle screw is an effective way to get the cylinders to run to a better degree. Now both needles do affect each other so adjust while the engine is running. Tune the idle screw to get a smooth idle and then throttle up to adjust the high speed needle. When throttling up does the engine "sag" and cut out? then richen the idle screw an eighth turn. With the engine at full throttle, adjust the high speed needle for highest speed and then back off 1/8th turn richer. It is hard and scary to adjust the high speed needle at full throttle. Placing fuel line tubing over the adjusting screw (1/4 inch longer than the screw) will help hold the screw driver in place while tuning. You will find with a careful ear listening to the engine there will be a back and forth tuning of both needles to achieve the best running and transition. Gotz from Vogelsang Aeroscale sells a slightly hotter spark plug that will assist in getting the colder cylinders to fire better. I hope I have been "clear" in my explanation. Experimentation for cause and effect will hopefully help you begin to understand this. There also is available an ignition system with a hotter spark for the 150. -Tom

Ha! i just saw your post! Also when you get down to 50/1 oil ratio, the cylinders will run better.

reyn3545

I bought my 150 "second hand" but unmounted or started... how do I know if I have the old or the new version?

Maxam

My Feedback: (62)

Moki 150s dated pre 11/00/2009 are the ones that will accept the turbulator. I had a 150 made before this date and the turbulator helped greatly as it does on my 215 now. -Tom

reyn3545

My 150 has been giving me fits. At idle, the #3 cylinder frequently loads up, and as I get over about half throttle, it sounds like the entire ignition starts to cut out briefly. I installed the Denso plugs, that seemed to help greatly with the idling issue, but the high-speed cutout problem is still there.

I think its time to try the Rainbow-tronics ignition... has anyone had success overcoming similar issues?

wphilb

My Feedback: (10)

My Moki 150 is one of the first 50 made, and Gotz was unable to get it to run on the old igntion, used all the tricks in the book. Knock on wood but ground testing on the new ignition (as detailed earlier in this thread) has gotten it to run the best I've ever had it running and seems to have solved the #3 cylinder issue. Talk to Gotz, you might send the engine to him and ask his guy to test run it for you and see if a new igntion resolves the problem.

I have yet to test fly the engine on the new igntion, getting my test airframe setup and awaiting suitable weather.

Whit

reyn3545

I talked to him this past week and we agreed that I'd try all the "easy" stuff first... plugs, the right prop, leaning out the low end on the carb, etc... problem stays. I feel like I've already spent $500 worth of time on this thing, and I'd rather spend $500 and fix it than $500 more time to not fix it. Every time I think it's running better, it's not. It is idleing better, the #3 cylinder is up to about 150 degrees at the exhaust port, about 20 degrees colder than the others, but when I throttle it up, it starts to cut out pretty erratically. It's not the high end tuning, it sounds more like the ignition is missing.

wphilb

My Feedback: (10)

Reyn3545,

reyn3545

I don't get up that way much, but it might not be a bad day trip. Do you have one of the Rainbow-tronic ingnitions?

wphilb

My Feedback: (10)

Yes, that was my point, I have one that's not hooked up to another engine, we mount yours on my test stand, pull off your spark leads and zip tie them out of the way, hook up the Rainbow-Tronic and see if your engine runs better. This only works if the day trip costs you less than the ignition though!

Whit

reyn3545

I think I could drive to Canada for less than the price of the ignition!

I think I'm tied up this weekend with Boy Scout projects, but maybe the following weekend... If it looks open, I'll PM you to see how your weekend looks.

Did the new ignition help your motor?

wphilb

My Feedback: (10)

The new ignition made all the difference on the ground, it's like a new engine, however I have not yet flown it so I can't say it's fixed until flight tests are over. That requires my test airframe to be finished which in turn requires my kids to stop bringing home new germs from daycare/school. It's a plot, I can sense it....

reyn3545

Ahh... I remember those days. Now, I can't pull him off the internet. Good kid, though. I appreciate the offer, I'll check with the "boss" for my schedule!

reyn3545

Here's something you don't see every day...

IFLYBVM2

My Feedback: (360)

Anybody had any luck getting in touch with Vogelsang lately ? His email auto reply says out of town until March 10, but today is 18th and phone just goes to voicemail too.
Thanks-Mike O

IFLYBVM2

My Feedback: (360)

FOUND him...

jairaksinen

So I did some experiments on my moki 250 over the weekend. I have a spare set of cylinder heads which gave me the opportunity to tune them a bit. Well I did not, but a friend of mine did some smoothening of the intake and exhaust ports. And then the intake copper seals were changed to match the intake channel size. Lastly the effect of the TBM velocity stack was tested.

So here are some results

Prop fiala 30X16 3Blade
Outside temp -4C
At sealevel

With original head and without Velocity stack 4650 rpm
With original head and with Velocity stack 4650 rpm
With tuned head and without Velocity stack 4830 rpm
With tuned head and with Velocity stack 4860 rpm

With tuned head, Velocity stack and new seals 4920rpm

So it looks like that there is more power, according to ThrustHP about 2hp more. Has anyone done the same? Any ideas if the engine can take the extra power?

reyn3545

I decided to purchase the Rainbow-tronics ignition for my 150 (turns out to be an RCS, not a Moki as advertised). I also got the velocity stack and moved to the hotter Denso plugs.

I had already taken the receiver and throttle servo off of my test stand and installed them in my plane, so just a manual throttle linkage for the testing...

I left the old ignition setup in the motor, installed the new hall sensor, tied the old plug wires out of the way, and connected the new ignition system.

A couple of flips with the prop, and it was immediately running smoother than it ever had before! It idles about 650 RPM, goes very smoothly through the range, and tops out at just over 5000 RPM with a 28x12 2-blade Laminated Xoar.

The #3 cylinder is still a good bit cooler than the others, so I may need to do a little more adjusting on the needles, but at least now I have a very stable, dependable ignition for the tweeking stage of the setup.

Thanks to everyone on the thread for their recommendations, and to Gotz, who I know is doing his best to keep up with a growing business! Time to put the motor back in the plane and get this thing in the air.

Jaketab

My Feedback: (2)

What's wrong with my Moki 250 ???
Blew the winter dust off it today. It started and ran perfectly.

After a short warm up - even the problem child #3 came up to temp with the others. Temps with cowl off were all in the 195-205F range.
Transition very good and top end was screaming.
I'm only guessing the problem is - that the carb needles are leaned and adjusted properly.
Additionally it could be those problem Denso U20M-U plugs too.

Have a theory about #3 cylinder running colder. Because of the rich mix it gets when new, it just takes this cylinder longer to run-in with initial temps being colder then the other cylinders ????

I'm running 50/1 Sthil with 90 octane ethanol free gas. Fuel pump and velocity stack. Ignition regulated at 5.1 volts.

On a serious note - one question please. Anybody have any experience with a Beila 32 x 22 prop on the Moki 250 ????????

Long live the well tuned Moki.
Jaketab

Maxam

My Feedback: (62)

Jaketab, Ya know I had the same problem with my 215. It started up and ran perfectly with excellent transition (turbulated) and would idle down to a walk. Here is to a great flying season!! That prop sounds like you won't be able to land! -Tom

Jaketab

My Feedback: (2)

Tom,

Landing the Gee Bee R3 has always been tough for me. Best conditions with headwind at 5 - 10 mph.
She comes in heavy and fast, but the flaps deployed at almost 90 degrees so a good job of slowing.
I had Beila 32x18 and it worked very well. I wanted to prop it down to keep from over rev.
Was afraid a 32x22 prop would be too much load.

Thanks - Jaketab
AKA - Jake Tabaretti

Maxam

My Feedback: (62)

Jake, Yep my 215 even rev's up quite a bit with a Fiala 32 x 18. I am going to try a 33 x 16 so I can land easier. I am flying a 37% Yak 55 SP. I hope that 32 x 16 keeps the engine rpms down. -Tom

reyn3545

OK, I FINALLY got my plane off the ground today. The Moki 150 was running pretty good, but it doesn sound like I get a sporatic ignition cut-out at mid-to-high throttle. I don't think it's just the #3 cylinder loading up, it sounded like the entire ignition was very briefly cutting out.

This is my first Moki, and I have it installed (for now) on a Pilot 35% yak. The plane weighs about 33 pounds dry. It flew very managable, but much slower than I had anticipated. If you get some height and build up some steam on the downhill (warbird style flying), it seemed to do pretty well, but still cutting out a little.

Obviously, I still have some tweeking to do on the motor, but for initial flight, it seemed to go pretty well.

Now, if I could just find a Meister Corsair that someone wanted to give away....

wphilb

My Feedback: (10)

That would be a real find...

heraldoboldrin

I receive my first moki this week.. S7 250.
I will use Lipo 2s on the ignition with regulator (6V is too much or will be better 5.3V)?
I read that i have to put oil every day on the valves.. where exactly?

regards

Heraldo