Hinckley Bill

My Feedback: (569)

I'll save everyone the effort of 'googling' for the recommended documents

BobH

My Feedback: (2)

Obviously you are not an engineer. Engineers, at least decent ones, are paid to produce a product that delivers what its intended design promises. What you seem to be saying is "hey thank you for making the new car I just bought. No matter I now have to supply the fuel delivery system for it".
If that makes sense to you in your world good for you. It doesn't in my world and I am an engineer.

Maxam

My Feedback: (62)

The Moki does come with a fuel system. It requires routine cleaning. The fuel pump is an improvement. My profession is none of your business. I am however capable of making my radials run beautifully in my world. I have clearly explained my experiences on this forum as well as the UMS/Seidel forum over the last ten years to help others as others have helped me. That is the point of these forums. I am sure Moki can afford a team of top engineers like Pratt and Whitney. Certainly Moki sells as many engines as GM does cars, right?

Captainbob

My Feedback: (4)

If the design is so good then why is there such an overwhelming list of complaints on the same issue with this engine, and consistently over last 10 yrs.?
Don,t get me wrong the Moki 250 is a great engine, but using an off-the-shelf chainsaw carburetor was a bad idea. The grease clogging of the impulse line caused in- flight engine failures and ensuing crashes. The fix for this was to offer an electric fuel pump to bypass the already on-board ,existing, Walbro pump at an outrageous price.
The Edsel was designed by engineers too!

BobH

My Feedback: (2)

There are a LOT of people who buy the radial engines who DONT have the pre-requist skills to fiddle and futz to get them to run properly. Is this the fault of the buyer? Probably for some of them yes. For others probably not. It's a DESIGN FLAW regardless of what some one is able to personally achieve.
Case in point if a fuel pump really does make the engine run properly then why doesnt it come with it in the first place? If you are spending 3- 4k for an engine what's another couple hundred bucks.

I dont care what your profession is that wasn't my point. You may be a wonderful fellow for all I know we just have a different opinion on value.

Captainbob

My Feedback: (4)

Sounds to me like we're in total agreement Bob.
To be told by the manufacturer or distributor that in order to get my engine to run right that now I need to spend 250.00 on a part that becomes another "single-point failure" in the system is a slap-in-the-face.

Hyjinx

Hey TomSounds like we should be adding one or two of these flawlessly engineered maintenance free radial IC engines to our working collections. Seems like these engineers really have it figured out. lol. Please stay involved. Read you on the other radial forums eh.
Aaron-
Oh an yeah. Where do I get one of those pinnacles of engineering prowess fellas. I would like to add one that does not require anything but adding gas to a tank.😃

RichardGee

My Feedback: (156)

It has been my observation that many who can afford to purchase a radial, aren’t qualified to operate a radial.

A model radial demands far greater attention to maintenance, tuning and cooling than single cylinder 2 and 4 stroke engines.

While I have criticized the Moki ignition AND the alleged need for an auxiliary fuel pump, engineering improvements will not close the gap with a lack of operating knowledge and experience.

As a modeler of 50 years, engine collector, and owner/flyer of 6 radials (gas and glow), like Tom, I am grateful that there are enterprising entrepreneurs willing and capable of offering these miniature mechanical marvels.

IF you are hell-bent on owning a Moki, then you must accept the extra costs and potential maintenance issues that come with it. IF not, consider a Valach, UMS or Saito radials.

On the used (glow) market, there are O.S., Magnum, ASP, Seidel and Technopower radials occasionally for sale.

I feel lucky to have this many choices in which to indulge my love of round engines.

Moebius44

My Feedback: (1)

Wondering if anyone knows if the Moki 300 use the same hub / bolt assembly as the 215 / 250?

Thanks...

EDIT: reason I ask is I have a NIB 215 with some (2-3 blade) props I'm about to post for sale and wondering if I can keep the prop drill jig...

Jaketab

My Feedback: (2)

Carb Kit for Moki 250 ??? Need to rebuild the carb on my Moki 250. Can someone please tell me the Walbro carb kit part number.?????
First flight of the day - engine ran perfect. Upon start and warm up for 2nd, flight the engine started bogging and quit. Lucky me this happened on the ground.
Engine bogs and quits when you try to advance throttle. Sounds as if starving for fuel. Maybe ingested something from the fuel.
Chased the needles with no luck.
I'm hoping for a simple carb fix.. Won't know for sure until I mount the engine to the bench stand.

Thanks - J Tab

Maxam

My Feedback: (62)

Jtab, if you are comfortable with removing and taking the carb apart, Check the fine screen on the pump side, remove the diaphragm side, taking out the needle and spring, use compressed air thorough all the jets BACKWARDS. Use a small tubing so you can get to the three idle jet holes and the main jet. If I recall you are using ethanol free fuel?
Do these operations sitting comfortably at a desk. Watch that tiny spring under the main jet needle!!! Brake cleaner is most effective or carb cleaner obviously! Pay attention to the orientation of the parts as you take the carb apart.
-Tom

Jaketab

My Feedback: (2)

Tom - thanks for quick reply. Yes, I plan to remove the carb and clean. Done it many times. Plan to rebuild when I have it apart. It's a pain to break down my CARF AT-6.
Maybe and air leak ???
I just checked Vogelsang's web site. I believe it's the Walbro WT 225. He should have it.
I use 100 LL AV Gas in both my Moki's and Valach 210. So far never a problem until now.

Thanks - J Tab

BTW - it's called a Jesus spring. When it pops up in the air and you lose it you say, "Jesus, where did that thing go."

Maxam

My Feedback: (62)

Jesus spring...Priceless!! Another thought, I like you had a perfect flight, then the next one the engine quit at low throttle. ?????? Inspection of the carb later while still on the engine; the low needle was only 3/4 open!! Should be around 1and 1/4 open. The only thing I can guess was the spring was wound from an adjustment and vibration allowed it to turn the needle in. I have trouble believing that but that is all I got! -Tom

Detlef Kunkel

Jtab did you check the pulsation line from the pump to the carb?
What about your fuel tank? 110 % sure that there is no broken line, closed filter / pendulum or something?

From one (good) flight to the next suddenly an unusable carb is really rare

Jaketab

My Feedback: (2)

Running fuel pump so pulse line is disconnected. I need to remove engine and inspect plane and fuel system throughout before any diagnosis.
Possibly some fibers from the felt clunk made their way to the carb? Possible vent line partly blocked. I have a long vent line in this plane..
Yes, I agree a sudden unusable carb is rare. My other 10 year old Moki with Top Hat ignition runs better with age and has never had a carb rebuild.
Will report back in a few days after I break down the plane and inspect. Thanks.

Jaketab

My Feedback: (2)

Surely goodness this could not be the problem ???? Dodged a bullet when the engine failed before the 2nd flight.
The threaded ring on the distributor connector was completely unscrewed, but the connection was still loosely intact.
Something for all to check on the Moki ignition.
I'm still not 100% this may have been the problem. Further investigation will tell.

Regards - J Tab

RichardGee

My Feedback: (156)

ALWAYS TAPE and Blue Loctite the ridiculously large and cumbersome Moki ignition connector so it does NOT come unscrewed from vibration.

Robert-H

Felt from a felt clunk! I would never use a felt clunk after I found tis inside my Walbro

Maxam

My Feedback: (62)

Wow! That is a helluva fuzz ball!

Jaketab

My Feedback: (2)

Referencing my recent Moki troubles, I found the $225.00 APS Fuel Pump went south. The burning smell of overheated wires is what eventually clued me in. The pump was running enough on start up to feed the engine. After a short period of running, the pump overheated and quit thus killing the engine. On last attempt to start the engine the pump took it's last breath. This is what made me believe it was a carb fuel starve issue. (No - the pump was never run dry and it's fairly new.)
Turns out the loose ignition connector was not the problem, but had it not been for the pump going bad, the loose ignition connector may have eventually done the plane in at some future point in time.
All in all lucky break, but not at all happy about the cost of a new pump.
Regards - J Tab

BTW - you non believers in the fuel pump can go ahead and snicker now. LOL

Maxam

My Feedback: (62)

There is a one year warranty on the pump. Hopefully you are within that time frame. I run my pumps on just 4.8 volts. Maybe that helps with longevity. What is important is your plane is safe. -Tom

Hinckley Bill

My Feedback: (569)

What brand felt clunk do you use? I've used walbro felt clunks with absolutely no issues like what your photo is showing for as long as I've been flying gas motors, well over 25 years.

mitchilito

My Feedback: (7)

Jtab, what’s with the cap-off on the bypass line? Where’s excess pressure to go?

Jaketab

My Feedback: (2)

Mitch - I run a continuous loop. The output flow line on the pump has a "T" connection. What fuel that is not being used by the carb is recirculated back to the fuel tank via the fill line.
No need for priming and there is no build up of pressure. There is always a continuous flow going through the pump.

Detlef Kunkel

Jtab,

I am afraid thats not the way to operate the pump correctly.

The return line MUST be connected with the tank. There is coming out just a little amount of fuel , but thats important for bleeding / venting the pump