Maxam

My Feedback: (62)

The ground revs are fine! This is an ideal ground RPM. The prop has such low pitch it is unloading in the air a great deal. Moki's require 16 inches or higher pitch.This is also ideal for warbirds. Problem here is a 30x16 4 blade is too much for the engine. I have no experience flying 4 blade props. For flying for now use a 32x18 or 32 x 20 two blade. Can someone else chime in on this? A 28x16 or 28x18 four blade prop?? A guy I talk to a lot in Germany uses a 4 blade prop on his P47 powered by a 250 and says he must throttle way back in dives and run around 3/4 throttle flying level. He has seen a few guys over rev their moki's and have a catastrophic failure with the crank failing! I cannot remember which prop he was using...sorry. -Tom

GeorgiaFlyer

Wow very nice flights! Does seem pretty high on the revs on your down lines. Otherwise nice flights and great short landings.

heinzulrich

That sucks, if that is the case, I'm sure there are many fellows out there that would like to be able to adapt a starter to the engines that they have, example; myself, would get three of them. wouldn't mind one for the 400 also, LOL darn arms getting sore....
Actually wouldn't mind a picture of how it is attached for anyone that has one already..

marksp

My Feedback: (9)

Biela 28x18 or 28x14 http://www.aircraftinternational.com...rbonProps.aspx

TonyBuilder

My Feedback: (11)

Anyone have fuel tank size off the top of there head for a Moki 180? I'm thinking 32oz as my EME 120 will fly 15min on that. I'm thinking the Moki is not using more then that? Also is tank placement critical as to elevation when using a pump? Mine will be about 1" above the center line!
Thanks

TB

Scott Prossen

32 ozs is plenty. I've been flying 250's for years with 64 ozs in it. after a 10-15 flight I always more than half a tank left.
I flew the 150's for years with a 32 oz tank for 10-15 minutes a flight and always had lots of reserve.

affas

I tried a search but couldn't find exact info.

My Moki 180 is going into a SBD 5 Dauntless and I wonder how much prop the 180 can handle with ground rpm of 4000-4200?


I am familiar with both 215/250 but seems like there are few reports from the 180 yet?

GeorgiaFlyer

I use a 26x18 on mine. Works really well.

affas

Do you think it can handle 28*16?

What rpm do you have on ground?

GeorgiaFlyer

Not sure if it would handle one, if you have that prop already try it out and see what rpm you get. I get about 4000 ground rpm with the 26x18. I rarely ever hit full throttle when in the air (mostly 1/2 to 3/4) especially on downwind legs. You don't want to over rev it these engines.

IFLYBVM2

My Feedback: (360)

I know it's buried somewhere in the 140 pages on this thread, but can anyone tell me if there are any noteworthy changes when comparing a newer Moki 250 with an older vintage MoKi 250's ? (Other than the new ignition box, which I am aware of )
Thanks-

marksp

My Feedback: (9)

I've been trying to determine the relationship between serial # and running changes, i.e new ignition. My serial # is numerically higher than a couple of buddies, but their engines came with newer ignition module.

Maxam

My Feedback: (62)

The newer Moki's have much better exhaust nuts on the pipes to the ring. -Tom

Growler84

My Feedback: (8)

Yes and on that note, the exhaust header pipes are bigger on the newer 250. Goetz told me a while back that the larger exhaust header pipes result in a bit more power...something on the order of 200 RPM from what I've seen running both the earlier and later 250 versions. My friend Mike has the newer 250 in a CARF Jug and my other flying buddy Phil has the older 250 in a CARF Jug, both turning 4-blade props. I've flown both models extensively and see no difference in performance. By-the-way, both of the above mentioned engines use the older "top hat" ignition so apparently "newer" 250s were also delivered with the old ignition. More trivia, Phil's older 250 has over 150 flights on it and he has never had to do anything to the exhaust header nuts other than to gently tighten them every 10 flights or so. The "gently" calibration is pinky-finger-only torque. I have the same older 250 as well and use the same procedure with no issues. I just mention this so maybe guys with the older 215/250 will not get wound up trying to make the header nuts a zero maintenance item.

reyn3545

I got an email from Rainbow-Tronic that they now have the Digital Ignition System released for the Moki 215/250 motors. Has anyone had the chance to try one? I put one on my 150 and it significantly improved the idle and transition on the motor. I'm thinking about getting one for my 250. Mine is the "old" style with the top-hat ignition system.

marksp

My Feedback: (9)

Price?

reyn3545

I don't know yet. If I remember, the one for my 150 was in the $400 range.

marksp

My Feedback: (9)

yeah...the upgraded Moki ignition for the S250 is $499 + shipping. I've yet to pull the trigger so I'm keen on understanding the diffs i.e. power source options, tach out, size, price, etc.

reyn3545

I spent at least that much trying to get my 150/running right... The new ignition had it running perfectly. I think I may give it a try for the 250.

GEEBEER3FLYER

Can anyone help please, spent 2 hrs this afternoon trying to start a new moki 400. Followed the instructions to the letter.... Nothing at all happened,

As per the instructions, im using 2s lipo, straight connection with no voltage drop as the ignitions now say 6-9v, plugs were sparking fine, fuel definately getting through, infact my feeling is it was flooding, particularly on bottom 2 cyls, i have experience of all sorts of engines and fly a 7cyl evo260 regularly and have no issues, the problem may well be me but cant see why i wouldnt even get a pop out of it...... Anyone got any suggestions or helpfull starting procedures?( is runnin on 32:1 premix as suggested)

wingstrut

Geebeer3flyer, I don't have a Moki 400 but my Moki 215 works great by fully choking the engine, open the throttle wide open, turn on ignition, make sure someone is holding the airplane, usually six flips will get it to fire, un-choke pull the throttle back to idle and another four it is running.
Have you pulled a spark plug to see if the ignition is functioning, it will be safer if you disconnect all the plugs, note: some ignitions require that you don't turn on the ignition with the plug wires not connected, I'm not sure on yours.
read your instruction to find out, If you have ignition and good fuel then if it doesn't crank on the procedure I explained above, then you have mechanical problems.
What ever you do don't give it a quarter throttle, half throttle, or anything other then wide open on the initial crank with choke closed, I did this originally and wore out four club members trying to get the thing to fire.
This is the procedure that Moki recommends and it works great..........Ron

GEEBEER3FLYER

thanks Ron, i will try again today, im pretty sure i followed instructions to the letter, as you described but hoping starting afresh with a dry engine will help.

wingstrut

Let us know how it turns out, Good luck, you have a wonderful engine there.
Is the little green light on your module turning on and off as you rotate the engine?
If it doesn't start today remove a couple plugs and see if you are getting fuel.
Ron

GEEBEER3FLYER

triedagain today, no luck, plugs are all firing, definately getting petrol, i think too much, its strange, if top cyl is number one then going clockwise, cylinder 4 is flooding ,and fuel was leaking out of it, a lot, the plug thread seems damaged when i unscrewed the plug, could it have not been seated properly. ? Still would have thought the other cylinders might have fired though, its very strange, im not unnacustomed to running allsorts of big enginesand followed instruction to the letter and nothing, ive reboxed it to send it back for a replacement and when doing so noted the board it was mounted to was cracked accross the mounting holes in the Cyl 4 position and the engine mount ring had left a deep depresion at that point on the board, coud it have been dropped i wonder? Tge box is undamaged but during packing perhaps? , anyway, not lost faith just dissapointed, it will go back to uk distributor in next day or so and hopefully get a replacement asap.

GEEBEER3FLYER

bTW, the other 4 plugs seemed fairly to very dry, with cyl 1 very black and carbony....