kevntri

My Feedback: (15)

I bought a used Extra with a Moki 2.10.
I got it running at 7200rpm and a good idle. The problem is the transition. At 1/2 stick it gets very rich.(gurgles like a 4 stroke)
Which needle should I be working on?
I have tried adjusting the low speed and any changes from where it is and it won't start.
Has anyone seen this issue before. My arm is about to fall off from flipping.
I an running FAI fuel with a F plug and no pump. The lines are short and the tank is right behind the firewall.

Thanks,

Kevin

alb1661

My Feedback: (3)

You should lean the high speed needle to max RPM, then turn it counter clockwise an 1/8 of a turn. Then adj. the low speed for good transition from low to high. Also moki's like to be started wet when cold. So, choke it by putting your finger over the carb before trying to start it. Your finger should feel wet. Be careful that's a powerful engine. I have 3 2.10 moki's and they all needed a perry pump and a glow driver to operate properly.

Good Luck

Steve

ExperimentalAviator

My Feedback: (15)

Kevin,

I have two Moki 2.1 engines that are set up the same firewall forward. I use the O.S. "F" plug and Omega 5% fuel. I tried FAI fuel but the throttle transition was not great and I could tell that the engines weren’t putting out full potential.

After watching another club member use the Omega 5% fuel I switched over and have never looked back. Both of my engine set-ups are side mounted with no glow driver needed and I use an APC 20x8 prop. My friend’s engine is mounted inverted, swings an APC 20x10 narrow APC prop, but otherwise has the same Cline Fuel Controller and fuel line routing as mine. His engine has not flamed out either. My engines are mounted on high drag airframes and my friend’s engine is used in a Mustang.

Get your high end needle set and then work on the low end. I still get the occasional “gurgles like a 4 stroke” just below ½ throttle, but I don’t operate at that setting very much so I haven’t worried about it. I tend to run my high end needle on the rich side since my engines are cowled up and I run wide open throttle most of the time.

Mike

kevntri

My Feedback: (15)

What is the Cline fuel controller? Is it a pump?

ExperimentalAviator

My Feedback: (15)

It's a fuel metering device; a one way check valve. Go here for more information.

http://billsroom.com/pcfs/products/CFS/fuelsysdesc.htm

I highly recommend the Cline PC fuel system for large two stroke applications. It also allows for the fuel tank to be located at any elevation. The fuel clunk in one of my tanks is 18 inches from the carburator inlet and it works flawlessly.

GotSky

A well tuned Moki needs nothing more than some 0 to 5% fuel and an OS F plug. (I use 5%) at 400 ft elevation Sideways, inverted or up right these motors are hands down the best on the market. I would suggest pulling the carb off the motor and give it a good cleaning. Remove the low speed disk and use a soft brissel tooth brush and some after run oil and give it a good once over. Check the O-Ring for seal when you put it back in. If it is lose then order a new one from http://www.hobbypeople.net/guru/HPS_317551801.asp
**************** part # 214539 - 10.180/21 - Mark Engines O-Ring - Mark 180/210/360 Carburetor $3.00 ***************

Also pull apart the needle and give it a good once over as well. Squirt fuel thorough all areas with some force.
Set the low end disk at the center mark
Set the needle at 1 3/4 turns out - adjust once you get her running
Use a 20x8 prop
Make sure your tank is using **large diameter fuel lines**.. This includes the clunk and brass tubes
Center the tank stopper/ line out let with the carb as close to the fire wall as you can.
Prime the motor ( get it really wet.. when you think there is enough give it a little more)
Hook up the glow driver and bump the prop backwards.. Watch your hand because she will get ya...

Low to high transition should be smooth the 5% fuel will help in this area. Make sure the low speed disk is seated all the way in the carb body. The O-Ring is all that holds the older ones in. If you are getting air sucked in it will mess with the low to high mixture. For the transition you should be using the disk for finite adjustments after you have properly set the high speed side. Very small adjustments should not make it harder to start...

Good LUCK!!!!

kevntri

My Feedback: (15)

I will work on it tonight and get it all cleaned out.
I have large line and the OS F plug already.
I always go leaner with the disk cause it sounds rich.
I will try richer.
I need to be about 3-5 degrees rich to get it to start. It will not start at the center mark.
I will give feedback soon......

Thanks to all

kevntri

My Feedback: (15)

I cleaned it all out and checked the needles...All looks good
I tried again to fine tune with no luck. I am still running FAI fuel. I don't have 5%
I have 6 inches of line from the tank to the carb.
If I lean the low speed out it runs good at mid stick but won't transistion and goes lean at full open.
I am about 6-8 degrees rich on the LS dial and 1.7 turns on the HSN to get the best performace. (still has a gurgle at mid)
Should I try a Perry pump next?

eagledancer

you might try a richer mixture at top end, i have found they like to be rich, yes a nice trail while flying is normal in my experiance with this engine

alb1661

My Feedback: (3)

Get a Perry Pump and put yout LS back to the mark. Start it and you will have to lean the LS a little. Have fun.

Steve

kevntri

My Feedback: (15)

Some more info....
My LHS doesn't have any pumps so I will have to order. They told me to try and plug one outlet on the pitts, run 16% oil with 5% nitro.
I tried adding about 3 oz of 20% nitro and 12% oil to a full gallon and I put a plug over one outlet. Not much change except maybe it moved the rich spot a little lower on the stick????
They did order 5% fuel for me.

kevntri

My Feedback: (15)

No luck on last nights try.....
It went lean after about 3 minutes and I had a dead stick. Good thing is I was in position and it stopped about 8 feet from me.

Which gasser should I be looking for???
41cc?
It says the Moki weighs 3.5lbs. I would like to keep the balance close if possible.

kevntri

My Feedback: (15)

This last run was good?
No cowl and held good. Slight gurlge just below mid stick is all.
I think it is just a tuning issue????
stay tuned

FBaity

My Feedback: (2)

I strongly recommend to use the information provided by ExperimentalAviator . I have used the Cline system on the 210 with great results and it doesn't cost much. Try it you'll like it.

Frank Baity
AMA 38026

RCdude13

My Feedback: (6)

I have 3 Moki 1.8's and 3 Moki 2.10's. I set up all of mine just as per the instructions. For fuel I use 5% Omega. I use O.S. #8 plugs which work better for me than the O.S. type F. You do not need a regulator if you can locate your fuel tank at the right height with respect to the inlet to the carb. Use large fuel line and tubing into the fuel tank and adjust the high speed needle to max minus 2 to 400 rpm. Adjust the idle disc so that the engine transitions from idle to wide open without 1) a huge puff of smoke (too rich therefore turn disc clockwise) or 2) engine dying (too lean therefore turn the disc counterclockwise). Note that the idle disc is VERY sensitive..a few degrees on either side of the neutral position is all they will ever need. I only use Moki's because I feel they are the most reliable, powerful, easiest starting and best running engines in RC. I go all summer without a dead stick.

Jeff Foley

My Feedback: (45)

I also strongly suggest you listen to Experimentalaviator.....I have used the Cline regulator, Omega 5% fuel and a 20-8 apc with great success. I also use the OS "F" plug.

kevntri

My Feedback: (15)

I ordered a Perry pump to try first $30
I will get a gallon of 5% and try it out.
Stay tuned

kevntri

My Feedback: (15)

I have the Perry pump and 5% in it now. (large line,clunk and filter)
Seems to transition stronger than before but still slightly out of tune at about 35% throttle. (this is the perfect position for normal flying)
It seems rich????
When I tune it at the bad point, I lean down the LSN...sounds good, but then it holds the R's at idle and is too lean at the bottom
I am at 1.2 turns out on the high speed and slightly lean on the low speed.
I ran it up to 7300 rpm and any leaner it started to puke out. I than backed it down about 1/8 turn.
The low speed runs good just lean or rigth on the mark.

It does seem to run better, just not what I am looking for yet.

Any more thoughts???????

Thanks,
Kevin

ExperimentalAviator

My Feedback: (15)

Kevin,

With my Moki's tuned slightly rich on the high end and "about right" on the low end my engines have a slight "gurgle" in the 25-35% power band. The only time I use that power setting is on my initial entry to downwind for landing with my Christen Eagle, so I just live with it since I spend so little time at that setting.

My high end power settings with a narrow blade APC 20x8 prop are 7200 RPM (set slightly rich). I don’t remember my idle RPM’s, but they are as low as you can get and still be smooth; and they do so reliably with just the slightest hesitation before making a rapid transition to full power.

I initially setup my first Moki using 5/32” fuel tubing made by Dubro, but later switched to a smaller fuel tubing (Large) with no ill effects. My friend is also using the same brand of Large fuel tubing on his Moki (inverted setup on a Mustang), and that engine also runs great. I don’t know if the I.D. of fuel tubing is standardized but we are using Prather fuel tubing, which I don’t think is available anymore.

The only negative that I have found with my Moki’s is that the engines want make an immediate transition from low power to idle power while in flight (on base leg turning final approach) unless the idle speed on the ground is set up as low as possible. That caused me to have to “go around” several times and forced me to set up my approaches where I had to come in higher and pull the throttle to idle further out. After getting the idle set to a lower RPM this has not been a problem, which is good since I prefer to fly my final approach with a touch of power and need the engine to transition to idle on demand. I do suspect that I could adjust the idle mixture just a hair more and maybe get rid of this problem, to the extent that the idle speed could be increased just slightly, but I have not tried to do so. An extremely low idle is usually not needed for a high drag biplane or monoplane with a big round cowling, but could be helpful on a slick airframe.

I am very satisfied with my Moki’s and they have never flamed out and turned my models into high wing loaded gliders. I could tinker with the needle settings more but just haven’t done so since these Moki’s have been dependable as is.

I hope that you can learn something from my engine setups to help get your Moki running to your satisfaction. Keep us posted.

Mike

JL1

My Feedback: (93)

Keventri, I wonder if that motor was fully broken in. Until they have at least a gallon through them they will not run well at all.

kevntri

My Feedback: (15)

Sounds like I am close.
This is an older motor so I am sure it is broke in.
I am reworking the paint on the cowl due to some flaking.
I will fly it soon and give an update

Thanks for the comments......

Kevin

eagledancer

just keep in mind these engines love to run on the rich side. dont try to lean them out too much or you will start having deadsticks
a slight (rich)smoke trail is normal on the one i have and the ones a friend of mine has
before i even put mine in the air the first time i put a gallon of fuel through it and i have been told they are not totally broken in until 3 gallons are through them.

kevntri

My Feedback: (15)

I took it to the field today. It started good and runs better. I think I am just not tuning it the best. I don't have a ton of time on the large glow engines. It ran about 220 degrees and had a good smoke trail. Just sound a little rich at mid stick. The problem is that is where I like to fly the Extra. I think I am going to sell this one and pick up a gas 50. I really do like the fit and power of the Moki though.
What should I ask for it with the new Perry pump, radial mount, Pitts muffler and carbon 20x8 prop?
It is in good used shape......


Thanks

JL1

My Feedback: (93)

At least $12 and I will be glad to take it off your hands

kevntri

My Feedback: (15)

I posted it at $180.00????
Sound about right with the spinner and stuff?