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MOKI RADIAL Care and Maintenence

Old 10-27-2020, 11:23 AM
  #4501  
Jaketab
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Would like to hear reviews on the CH Ignition for the Moki.
Anyone ???

https://ch-ignitions.com/product/cdi...50-180-215250/
Old 10-27-2020, 01:31 PM
  #4502  
IFLYBVM2
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While not having used one myself, I have spoken to 2 or 3 guys who said the CH was the difference between chunking the motor and keeping it. Frank Tiano is among those that uses it as well.
The 250 does not seem to experience the same ignition failures that the 150/180 series does, for the most part, for whatever reason.
Adrian at CH seems to know his stuff and has been helpful every time I have ever asked on non Moki related ignitions.
Old 10-31-2020, 02:19 AM
  #4503  
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Hello,

i managed to start for the first time my 180s on the test stand. It took me a while to understand that it wanted a bit more throttle to start.
I have couple of findings that i would like to share.
The response of the throttle was slow with white smoke coming out of the exhaust. I have already made the throttle servo slower than normal. I do not know to what speed i should go.
I have leaned the Low needle and the response improved but still i needed to manage the stick a bit slower than the servo speed. The Low now is at 1rev from completely closed.
The idle revs are quite high i think at 1500RPM with the throttle completely closed.
The temperatures from the cylinders are about 120C except the number 3 (counting anticlockwise) which shows about 80C to 90C.
You can see at the photos that the exhaust side close to cyl 3 spits a lot of oil although the right one (when looking from the front ) seems normal.

I would appreciate any feedback since i am rookie on this kind of motors.

Thanks in advance,
Lawrence




Old 10-31-2020, 11:05 AM
  #4504  
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Tziger,
A few tips I have learned over the past 9 years with my 2 Moki's.
1. Proper oil and ratio at 45-50/1. I use Amsoil Dominator.
2. Number 3 is always slow to come up to temp. Leaning the low side needle is mandatory. I tune while the engine is running. With engine running at slow idle, lean the low screw until the rpms drop, then open until you get the fastest idle speed with good transition.
3. The exhaust manifold nuts to the collector ring will work loose when the engine is new. Never, never, never tighten the nuts while the engine is warm or hot. Only tighten the nuts with minimal torque. The Teflon rings take some time to fully seat. Overtightening them will cause the seals to deform.
4. The black oily exhaust residue should cease after about 1 hour of running in.
5. Only run the motor for short periods on the ground to prevent overheating. Baffling and proper exit air in the cowl is a must.
6. The Moki is very responsive to the throttle input. However, slow the throttle with your transmitter to prevent slamming it open and closed. Much better for the engine to open and close the throttle slowly.
7. Did you remove the idle stop adjustment screw? It may be preventing your throttle lever from going closed all the way. The Moki will have a reliable idle at 1000 or less.
8. Lots of good tips in this forum, but different things work for others.

Regards - J Tab
Old 10-31-2020, 01:33 PM
  #4505  
Moebius44
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Great advice Jaketab...

I'm wondering about partially restricting air flow to #3, just enough to bring the cylinder temperature up a ways.
Old 10-31-2020, 03:42 PM
  #4506  
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Originally Posted by Jaketab View Post
Tziger,
A few tips I have learned over the past 9 years with my 2 Moki's.
1. Proper oil and ratio at 45-50/1. I use Amsoil Dominator.
2. Number 3 is always slow to come up to temp. Leaning the low side needle is mandatory. I tune while the engine is running. With engine running at slow idle, lean the low screw until the rpms drop, then open until you get the fastest idle speed with good transition.
3. The exhaust manifold nuts to the collector ring will work loose when the engine is new. Never, never, never tighten the nuts while the engine is warm or hot. Only tighten the nuts with minimal torque. The Teflon rings take some time to fully seat. Overtightening them will cause the seals to deform.
4. The black oily exhaust residue should cease after about 1 hour of running in.
5. Only run the motor for short periods on the ground to prevent overheating. Baffling and proper exit air in the cowl is a must.
6. The Moki is very responsive to the throttle input. However, slow the throttle with your transmitter to prevent slamming it open and closed. Much better for the engine to open and close the throttle slowly.
7. Did you remove the idle stop adjustment screw? It may be preventing your throttle lever from going closed all the way. The Moki will have a reliable idle at 1000 or less.
8. Lots of good tips in this forum, but different things work for others.

Regards - J Tab
I too have two Moki 250s and earlier had a 180 I've been running without any issues for about 3-4 years now. All of these are awesome tips...total agree with all of them great advise.
Old 10-31-2020, 05:36 PM
  #4507  
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Originally Posted by Jaketab View Post
Tziger,
A few tips I have learned over the past 9 years with my 2 Moki's.
1. Proper oil and ratio at 45-50/1. I use Amsoil Dominator.
2. Number 3 is always slow to come up to temp. Leaning the low side needle is mandatory. I tune while the engine is running. With engine running at slow idle, lean the low screw until the rpms drop, then open until you get the fastest idle speed with good transition.
3. The exhaust manifold nuts to the collector ring will work loose when the engine is new. Never, never, never tighten the nuts while the engine is warm or hot. Only tighten the nuts with minimal torque. The Teflon rings take some time to fully seat. Overtightening them will cause the seals to deform.
4. The black oily exhaust residue should cease after about 1 hour of running in.
5. Only run the motor for short periods on the ground to prevent overheating. Baffling and proper exit air in the cowl is a must.
6. The Moki is very responsive to the throttle input. However, slow the throttle with your transmitter to prevent slamming it open and closed. Much better for the engine to open and close the throttle slowly.
7. Did you remove the idle stop adjustment screw? It may be preventing your throttle lever from going closed all the way. The Moki will have a reliable idle at 1000 or less.
8. Lots of good tips in this forum, but different things work for others.

Regards - J Tab
Great, thanks a lot for the advice.

BR,
Lawrence
Old 11-14-2020, 09:17 AM
  #4508  
RichardGee
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Guys,
I have two Moki 215/250 props I will be posting for sale on Monday, but offering them here first:
  • Bambula 32x18, brand new, never used.
  • XOAR 32x14, used for bench testing. Comes with prop cover.
$60 Each PLUS actual shipping costs. I estimate shipping will be less than $15 ea.

Rich - [email protected]

Old 11-24-2020, 06:56 AM
  #4509  
jraycut
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I've been reading through this thread quite a bit, mainly about the 150 and problems w getting #3 cylinder to come alive (to run more consistanltly). i saw in posts dating back to 2011 w comments being made that the 150 up to the 300 all have the same carbs. I looked on several websites and indeed, they do sell a replacement carb that is supposed to fit all of those engines (150, 180, 215, 250, 300) as the mfg's list it as so.

I also read where a guy was wanting to swap out the carb for a smaller one (perhaps one from the zenith G38), the topic kinda faded off and I was curious if anyone had tried this and what the results were? i would think by now - that Moki would have gotten this feedback after all these years and came up w something to help it run more reliably(?).

Ive tried hotter plugs, messing w needles, tore down carb and cleaned thoroughly, servo speed, etc. The #3 on mine fires, but not regularly and i know the 150 isn't putting out the numbers that it should. Is there anyone out there that has a 150 and was successful w it running consistently on all 5 cylinders? and if so - what was your method in achieving this?

Thanks,
Joe
Old 11-24-2020, 12:12 PM
  #4510  
Moebius44
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Originally Posted by jraycut View Post
I've been reading through this thread quite a bit, mainly about the 150 and problems w getting #3 cylinder to come alive (to run more consistanltly). i saw in posts dating back to 2011 w comments being made that the 150 up to the 300 all have the same carbs. I looked on several websites and indeed, they do sell a replacement carb that is supposed to fit all of those engines (150, 180, 215, 250, 300) as the mfg's list it as so.

I also read where a guy was wanting to swap out the carb for a smaller one (perhaps one from the zenith G38), the topic kinda faded off and I was curious if anyone had tried this and what the results were? i would think by now - that Moki would have gotten this feedback after all these years and came up w something to help it run more reliably(?).

Ive tried hotter plugs, messing w needles, tore down carb and cleaned thoroughly, servo speed, etc. The #3 on mine fires, but not regularly and i know the 150 isn't putting out the numbers that it should. Is there anyone out there that has a 150 and was successful w it running consistently on all 5 cylinders? and if so - what was your method in achieving this?

Edit: it would be prudent to see where in the rpm range #3 begins to drop out by measuring cylinder temp real-time (note it will take a bit for thermal energy to reduce enough to establish - hysteresis) . Don't use an IR meter - way too inaccurate (use a thermo-couple).

Thanks,
Joe
The assumption would be that somehow - the air detection / rate-of-flow / fuel metering by the carb is a negative) factor throughout it's operating range. I don't think it is; all it would do is push the detection and resulting A / F further up in that particular carb's operating range. Smaller means a smaller diameter / cross sectional area through the carb throat, which is likely to reduce commanded air rate-of-flow at max rpm and some range below that (think of any restrictor plate racing and how clumsy that works out at producing PWR / TQ)...

Edit: Maybe work out first where in the rpm range #3 is actually dropping out (if ever - this would be valuable no matter what). Measure temp (note hysteresis / delay) as you slowly reduce rpm (don't use an IR meter, instead a thermocouple - IR will not measure accurately in this case for multiple reasons).

Last edited by Moebius44; 11-24-2020 at 01:24 PM.
Old 12-02-2020, 06:22 PM
  #4511  
orthobird
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question for the MOKI aficionados,

with a MOKI s250, using the most common propeller, what is the estimated thrust / output?
Old 12-02-2020, 06:52 PM
  #4512  
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I am running two 150s successfully though not 100% as some might desire.

I am running the replacement ignition off of a three cell A123. I have a hotter plug in the #3 cylinder and I’m running a 28 x 12 prop (from memory) vs the 26x16 which I never liked. I’m also running the fuel pump also through Vogelsang Areoscale as was the ignition. Battery from NOBS batteries.

I'm not trying for high RPM and I fly sedated compared to some out on YouTube but it works for me. I’m flying a 12’ Telemaster and a BUSA N28 both with the setup as described. I had one in an F4U but wasn’t reliable at the time. I probably could but it back together now.

It’s disappointing that Moki sells an engine with as much need for tweaking and aftermarket additional stuff. I know there are those who made the stock setup work but I’m not one of them. I can’t say enough for Dr Gotz and his support.

Cheers,

Whit
Old 12-03-2020, 04:56 AM
  #4513  
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Originally Posted by orthobird View Post
question for the MOKI aficionados,

with a MOKI s250, using the most common propeller, what is the estimated thrust / output?

Not an exactly answer to your question, but on a Moki 180 at 4800 RPM a Menz 28 x 16 2 blade pulls 17kg static
Old 12-03-2020, 07:06 AM
  #4514  
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Originally Posted by jraycut View Post
I've been reading through this thread quite a bit, mainly about the 150 and problems w getting #3 cylinder to come alive (to run more consistanltly). i saw in posts dating back to 2011 w comments being made that the 150 up to the 300 all have the same carbs. I looked on several websites and indeed, they do sell a replacement carb that is supposed to fit all of those engines (150, 180, 215, 250, 300) as the mfg's list it as so.

I also read where a guy was wanting to swap out the carb for a smaller one (perhaps one from the zenith G38), the topic kinda faded off and I was curious if anyone had tried this and what the results were? i would think by now - that Moki would have gotten this feedback after all these years and came up w something to help it run more reliably(?).

Ive tried hotter plugs, messing w needles, tore down carb and cleaned thoroughly, servo speed, etc. The #3 on mine fires, but not regularly and i know the 150 isn't putting out the numbers that it should. Is there anyone out there that has a 150 and was successful w it running consistently on all 5 cylinders? and if so - what was your method in achieving this?

Thanks,
Joe
Jay,

My 150 runs pretty smooth. I am using the Rainbow Tronics ignition, and the Denso plugs on all cylinder. The only real modifications were to slow down my throttle servo and I added hot air exits. Upper cylinders are 200- 220 and lower cylinders are 180-200. It took me 2 seasons to get it like this.

I do maintenance every 4 flights. There is usually a valve or 2 that needs slight adjustment, and a couple of the intake and exhaust 17MM nuts are loose. But the next flight after maintenance it purrs awesome.

These engines are very demanding, and take patience to get dialed in.

Jeff
Old 12-03-2020, 07:17 AM
  #4515  
wphilb
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Jeff,

Would you mind describing your valve adjustment process? That is one thing I’m not as good as I should be. I’ve nit adjusted mine as regularly as you have and might start if you are finding it that needed.

Sincerely,

Whit
Old 12-03-2020, 08:04 AM
  #4516  
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Originally Posted by wphilb View Post
Jeff,

Would you mind describing your valve adjustment process? That is one thing Im not as good as I should be. Ive nit adjusted mine as regularly as you have and might start if you are finding it that needed.

Sincerely,

Whit
Watch this clip cot 1 and 2

Coffee with Dr. G - Episode 1 - HS Heilemann Carbon Pushrods for Moki - Vogelsang Aeroscale

Old 12-03-2020, 08:14 AM
  #4517  
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Originally Posted by fatfreddy17 View Post
Jay,

My 150 runs pretty smooth. I am using the Rainbow Tronics ignition, and the Denso plugs on all cylinder. The only real modifications were to slow down my throttle servo and I added hot air exits. Upper cylinders are 200- 220 and lower cylinders are 180-200. It took me 2 seasons to get it like this.

I do maintenance every 4 flights. There is usually a valve or 2 that needs slight adjustment, and a couple of the intake and exhaust 17MM nuts are loose. But the next flight after maintenance it purrs awesome.

These engines are very demanding, and take patience to get dialed in.

Jeff


My procedure: lean as possible on L needle (around 1 turn or maybe less and throttle delay) then attach temp sensors on all cylinders, after start, high rev idle, fiddle with throttle back and forth, observe temp closely, high rev idle and full rev, until al cylinders have similar temp, then you can take of. it can take a while but suddenly they are all working, reason: possibly there could be some fuel left in the crank case, that put out No 3 cyl
Old 12-03-2020, 09:29 AM
  #4518  
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Originally Posted by Robert-H View Post
My procedure...attach temp sensors on all cylinders
How and where are you attaching temp sensors? Are you drilling cooling fin near exhaust port or securing with head bolt, other?

Cheers
Old 12-03-2020, 09:32 AM
  #4519  
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Originally Posted by wphilb View Post
Jeff,

Would you mind describing your valve adjustment process? That is one thing I’m not as good as I should be. I’ve nit adjusted mine as regularly as you have and might start if you are finding it that needed.

Sincerely,

Whit
I cut a sliver of a 0.006" shim, bent the shim 90, and then soldered the shim to an old screw driver to make it easier to hold. Rotate your prop until the push rod is loose, then I adjust valve until the shim snaps into the valve spring slot. Always keep your screw driver in the adjustment screw as you tighten the nut down. The trick is to be consistent in how you "feel" each valve gap.

I also oil each rocker before EVERY flight. Maybe overkill, but I do have a nice running motor, so I'm keeping as is.

1 loose nut or 1 valve a couple thou out of adjustment makes a world of difference how the motor runs.
Old 12-03-2020, 10:59 AM
  #4520  
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Originally Posted by marksp View Post
How and where are you attaching temp sensors? Are you drilling cooling fin near exhaust port or securing with head bolt, other?

Cheers
I placed them between the two valves, pulled forward from back, by a wire attached in a hole drilled in the front flange, some grinding between the two valve "towers" to form a wedge big enough for the sensor body, the wire is tighten to make a firm attachment, I used Powerbox PBS-T250 5 channel sensor
I am sorry I am not allowed to post an image yet..
Old 12-03-2020, 11:44 AM
  #4521  
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Thanks! These are great. Dr Gotz is an expert in these and has helped me in the past.

The valve adjustment procedure is something I dont have the feel for. I can get them close but Im not sure Im within a thou like I would like to so Im not doing them as often as I should,

Thanks again!

Originally Posted by Robert-H View Post
Watch this clip cot 1 and 2

Coffee with Dr. G - Episode 1 - HS Heilemann Carbon Pushrods for Moki - Vogelsang Aeroscale

Old 12-03-2020, 11:50 AM
  #4522  
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Thanks! I have the shims, I bought a set based upon advice from friends running these in Australia. My issue is the feel required with the shims. I think Im close but not confident. That said Ive managed a large number of flights over the past years and once we got the Rainbow Tronics ignition and the fuel pumps ive been pretty successful. I suspect that the higher diameter, slower RPM props I use may make the valve setting less sensitive ?
Thanks again!

Whit

Originally Posted by fatfreddy17 View Post
I cut a sliver of a 0.006" shim, bent the shim 90, and then soldered the shim to an old screw driver to make it easier to hold. Rotate your prop until the push rod is loose, then I adjust valve until the shim snaps into the valve spring slot. Always keep your screw driver in the adjustment screw as you tighten the nut down. The trick is to be consistent in how you "feel" each valve gap.

I also oil each rocker before EVERY flight. Maybe overkill, but I do have a nice running motor, so I'm keeping as is.

1 loose nut or 1 valve a couple thou out of adjustment makes a world of difference how the motor runs.
Old 12-03-2020, 12:56 PM
  #4523  
Moebius44
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Another tip: learn cold clearance feel as well as the actual hot clearance (it will be smaller) and write them down for future reference...
Old 12-03-2020, 01:50 PM
  #4524  
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I've been setting valve lash at 0.003" ( inches). This has worked from me from day one.
The instruction manual that comes with the Moki lists the clearance in millimeters from 0.05 to 0.08. (mm)
Converted that is 0.002" to 0.003" (inches)
There are 2 cam lobes for both intake and exhaust. Always check the clearance twice - every 2nd rotation of the prop to avoid a setting that is too tight and risk burning a valve.
Regards - J Tab
Old 12-08-2020, 02:00 PM
  #4525  
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Originally Posted by orthobird View Post
question for the MOKI aficionados,

with a MOKI s250, using the most common propeller, what is the estimated thrust / output?
Hello, today I mesured my Moki 300, with a SEP 34/18, 3950rpm pulled 29,92kg. The proportion is equal as mesured Robert H with his Moki 180, I think with yours Moki 250 it sould be +- 25kg.
Here is my video:

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