MarkShapiro

My Feedback: (52)

Going to be using flexpipe over the exhaust ring outlets to channel exhaust out of my Bearcat. How are you guys securing the flexpipe to the exhust pipes?

germrb

My Feedback: (3)

Mark,

I assume that the pipe diameter is close to or the same as the OD of the exhaust ring outlets. I have been using stainless steel flexible piping on my WACO. I split the flexible pipe every 90 degrees and about 3/4" long and use standard hose clamps. I also fill the split ends with some Permatex Ultra Copper gasket sealer just to eliminate leaks. I haven't had any problems or serious leaks.

TheRickster

My Feedback: (12)

Ran the 215 somemore on the bench.. I ran it about 5 minutes at mid throttle then opened it WOT and it tached 4800rpm still a little on the rich side with a Bolly 32X14.. It idles very nicely at 700 or so and all the plugs are burning a dark tan color so far.. I am thinking about trying to find out what the tubing fitting size is and just running 5 straight pipes on it like the real Gee Bee was.. I bet it would sound great as well..

germrb

My Feedback: (3)

Rick,

Sounds like an excellent idea. First of all, it would immediately remove the majority of the heat from the cowl and allow the engine to run much cooler.

Someone had an early biplane (Fleet ?) at Frank Tiano's Monster Flyin last year with a 150 configured that way. It was surprisingly quite considering and sounded more realistic. Sorry, I can't remember whose airplane it was.

You shouldn't have too much trouble building some scale stacks.

SoCalSal

My Feedback: (16)

Exhaust tubing is 20mm outside diameter. That is the two down outlets from collector ring

germrb

My Feedback: (3)

Rick,

I found a picture of the 1/3 Fleet Biplane with the 150 stacks. It appears that he simply cut the existing stacks away from the exhaust ring. You could do the same thing and then weld some scale extensions to them.

Good luck,

wildbills21

I run the 215 on a BUSA Stearman and was thinking about doing the same thing. What are the pros and cons of running straight pipes so to say. Are there any major concerns running the motor this way.

Wild Bill

tony67

My Feedback: (51)

I have a 215 on the fifth tank of gas and noticed the breather tube going to the carb is not clear but kind of foggy.Would it be time to clean it out? does the tube pull off the end connectors and how.

Scott Prossen

Hey Tony,

Welcome to the thread. Lots of good info in here. Although it's a long thread you really need to read through it as you have time. There are some very good contributions that will help you to enjoy and protect your investment in that MOKI. Guys from all over the world have taken time to share their experiences with all of us and they are very helpful in operating and maintaining these little gems.

Yes, that clear tube should be cleaned as it provides the fuel pressure to the carb. It has been stated that even a 30% clog can have negative effects on the fuel pressure. Just push in on the blue ring portion of the Festo fitting gently and while doing so pull the tube out. Do the same on the other end and then clean out the tube. I take a tiny piece of paper towel and ball it up then push it through the line several times with small diameter wire. Do it until the paper towel comes out clean. Then replace the tube by just inserting the ends back into the fittings. Slight pressure will allow the tube to fit right into the Festo. To check it just give the tube a slight tug to see if the Festo has gripped onto it. If so, then you are done. Make sure to check everything else when you have the cowl removed and enjoy many more hours of that beautiful 5 cylinder sound!

Happy Landings!
Scott

tony67

My Feedback: (51)

Thank you very much for the quick reply Scott and for starting this thread.It came right off just like you suggested.I have learned so much from everyone's experiences thank you all.

I have a two blade solo prop that I just tried running and with it dialed at 14 pitch (so I think) I am only getting 3800rpm and was getting 5300rpm with a Zoar 32-10. I find that when I dial down to home it does not stop at once but will sort of tighten to a stop but at the highest setting (24 pitch it stops at once when it reaches max rotation.So if I start to rotate and count the units from home (1 on the dial) to 10 3/4 I should be at a pitch of 14 yet I am only seeing rpm's of 3750 was hopeing to see 4200 -4300rpm.
Is there any way for me to get a true point of referance of pitch with this prop and go from there.
I may just set the rotation to get a rpm of 4000 to 4300 and leave it at that but would be nice to know at what pitch I am dialed in at.
Thank you

nine o nine

My Feedback: (1)

I've found that after much run time and cleaning the pulse tube several times that vaporized grease has gathered in the carb inlet side and finally clogged the fuel inlet screen. Something to watch for......... Mitch

taygher

Hi guys,

I have a question that perharps already has been answered somewhere in this thread.
(When a thread gets this big it's bound to happen at some point, right?)

I am running a Moki 250 in a 3m C-ARF Yak, no mods, Biela 2-blade 32x18 and 50:1 fuel mix with Klotz R50.
I have 28 flights on the plane and when flying it yesterday I was able to sort out the manouver that causes the Moki to hesitate for a short while.
It has happened before but not that often so I never really thought about when to expect the problem to occur.

In my case the engine gets really quiet for a short while after a 4- or 8-point roll, once yesterday for too long.
Just as my brain screamed -DEADSTICK!! it came back to life.
The engine runs great i every other aspect, I have tried various manouvers such as stall turns, avalanches and fast rolls (several in a row) and nothing disturbs the Moki other than 4- or 8-point rolls.

Has anyone experiences something similar?
I am thinking fuel lines and/or clunk but then the engine should run poorly in other situations as well.
Can the H-needle be on the lean- or rich side or do I need a fuel pump?

I hope you experienced Moki-owners can give me some ideas about this.


Thanks and best regards,
Taygher

TheRickster

My Feedback: (12)

Would seem that it would have to be a clunk following issue not following the fuel during slow or hesitation rolling maneuvers. A fast roll would tend to sling the clunk with the fuel. Maybe the clunk line has swollen some and the length has increased and the clunk is lodged on one side or the other thus not allowing the clunk to follow..

Rick

taygher

Hi Rick,

Thanks for the input, I will check this asap.
The Yak is my first gas powered plane and I have no previous experience with tygon fuel lines.
I like to have the clunk line as long as possible in my planes and I don't think I made an exception this time.
If tygon expands a little after a while when being in contact with gas this could be the problem!

It will be really easy to see if this is the case by just lifting the tank out of the plane and holding it in some suitable positions in front of a lamp.


Best regards,
Taygher

germrb

My Feedback: (3)

For those of you who haven't found this YouTube video,

http://www.youtube.com/watch?v=Kj6vZ...layer_embedded

Enjoy,

nine o nine

My Feedback: (1)

While working on an article for Model Airplane News this video was shot...love the sound of that Moki. Mitch
http://www.youtube.com/watch?v=Yv6MTjfLMCU

germrb

My Feedback: (3)

Mitch,

Very nice to see a professionally made video for a change. Excellent!

By the way, have you any data on in-flight engine temperatures? I'm still struggling to get all the cylinders of my 250 reasonably uniform and in the 200 - 220 F range. I got a fuel pump from Goetz, but haven't had an opportunity to get it installed.

Looking forward to the MAN article.

Best,

jfassino

Turning up the volume on a Moki sounds good to me. anyone have a decibel reading on a Moki without a collector ring? We have a 99 db limit at 15 feet for our field.

Jim

TheRickster

My Feedback: (12)

I decided against the open stacks.. I pulled the collector ring off mine and put larger dumps on it, .875" and it gave it a little more crackle ..

Here is a Valach radial with open stacks, I did not care for the sound myself..

420cc 5 cylinder [link]http://www.youtube.com/watch?v=bRINLtDfR14&feature=related[/link]

800cc 7 cylinder [link]http://www.youtube.com/watch?v=CvB3ZbRLeo4&feature=related[/link]

nine o nine

My Feedback: (1)

Bob, I don't have a temp gun so I really don't know what my 215 temps are. Sorry I can't help there. A friend's motor is set up with baffles and we've spent considerable time tuning it and found that it seems impossible to get the lower two cylinders as warm as the top three which run about 220-230. As long as the lower two are firing and you get decent RPMs I wouldn't sweat the difference in temps. I have no experience with a turbulator but it's supposed to help even the mixture for a more balanced temp of all the cylinders. Anyone with factual data using a turbulator before and after??? Mitch

MarkShapiro

My Feedback: (52)

Hey Mitch,
The WACO is awsome. Did not make it to Top Gun this year, so I hope to see you, and the WACO, at Monster planes this year. Bringing a couple of models myself this year, so I should keep you busy tuning my engines .

nine o nine

My Feedback: (1)

Wish I could come Mark but it's not in the cards this year. Have a great time....wish I was going. Mitch

nine o nine

My Feedback: (1)

I've seen and heard the 150 Fleet with the open stacks and I think it's quieter than with a collector. It just might be an impression but I think the exhaust is dissipated rather than concentrated. Mitch

MarkShapiro

My Feedback: (52)

That's too bad, Mitch. We'll miss you. Hopefully next time.

Scott Prossen

Hey Moki Dudes,

Been a while since I've had any real MOKI content to contribute. What I have has already been covered but here it goes anyways!
Over the past several weeks I've been flying the AirWorld FW190/ Moki 215 combo that I purchased and posted a picture of in post #755 on page 31. Couple things from this experience that I want to mention.

1.) Battery / Ignition voltage; I am trying LI FE type batteries for the first time. They are 6.6 volt and I have them plugged direct into the Rx. I'm using the same on the ignition but have run it through a voltage regulator reducing it to 5.4v. Went up flying and had all kinds of missing and spitting from the engine. I tuned and tuned and ran all new fuel lines.... yadda yadda yadda. Flew again and had the same problem. Long story short...I got an adjustable voltage regulator and dialed it lower to 5.0 - 5.1v Problem solved ever since. I was not completely aware of how sensitive these ignitions are. Can't believe .3 - .4volts would make all that difference but it did. BTW, I love the batteries. Very light, powerful, stable, holds the charge forever or so it seems, and I can charge them in about 15 to 20 minutes in the field.

2.) APS fuel pump; This plane came to me with an older version APS fuel pump already installed. It is a fantastic addition to an already great engine and here's what I see as the benefits. It makes the first cold start of the day very easy. Pump and ignition ON and full throttle/choke and in three flips I get the pop. Choke OFF and throttle to idle and within 3 more flips I'm in business. In other words there's no need for a lengthy priming series of flips. The engine response is extremely fast with these pumps. Not sure thats important...just something else I noticed. The RPM at the top and bottom change for the better as a result of its use. The low gets lower and the high gets higher from the fuel pressure being always there which in turn allows you to lean out the H/L needles. The fuel distribution seems slightly better as well because the temps of all the cylinders appears closer from 195 to 220 F. The plugs have a better look over all as well.

Both these items have been covered before but I thought someone might benefit from what I found this time around. Love the LI FE batteries and voltage regulator and I am going to put an APS fuel pump on any new MOKI installations I use. I may also go back and put them on the others I am already flying for the ease of starting issue and smoother running condition. Love that idle around 700 RPM...Padum Padum Padum!!!

Round engines rule,
Scott