Ragz

The engine is around 4 years old, but not run much. The plugs are very clean and all of them are working. How can you tell when the plugs fire? I ran the engine for around 3-4 mins on the ground. My desired max rpm is 3800 in any case. I am not worried about rpm here. I am only wondering if the cylinder temps are ok.

thanks

pmosf

This is just my opinion, I let the experts to confirm or not, but for me the temps are not ok. I'm pretty sure the mixture does not reach cylinders C and D at least at idle rpm. I have the same behavior on my mine, cylinder C is 45-50C at idle and reaches the same temperature as the others above mid throttle. I can also clearly hear the change of sound.

Lletisso

Hello, I have a new Jeti Dc 16 II , and I would like to set up the APS electic pump to my Moki 300, is as simple to conect the RX port to a free chanel to switch it on or off, or it has to be mixed to the throttle chanel? to give the pump more or less power depending to the throttle position..? I know that I have to conect the batery at the Bat. port.
Anybody using a APS fuel pump and a Jeti Transmiter?

Thank you very much!!!

Jordi

Jaketab

My Feedback: (2)

If you have the programable APS Pump you can do either. I use a curve mix with the throttle as a master and the pump channel as the slave. The pump operates at a lower output volume when the rpm's are low. I use a common switch to turn on/off both the pump and the ignition.

Jaketab

My Feedback: (2)

Does anyone have a scanned 1:1 picture or drawing of the Moki 250 baffle?
It would need to be scanned or converted to a PDF file or a format my computer would read.

Thanks - J Tab

Lletisso

Thanks Jaketab!

g257945

So, like most of us Moki radial owners, I too have experienced the dreaded cold engine start issues. I've contemplated adding the electric fuel pump and assorted other do-dads but I keep coming back to the thought that there has to be a better way. Adding the pump is simply just providing positive pressure to incoming fuel to the carb. Why not pressurize the tank? I stumbled upon an idea that I put into practice this past weekend on my 180 that worked beautify with no added weight or cost. First, a remount of the tank to raise it up so its nearly level with the carb. Next and I'll point out that I am a 2 fitting guy for the tank. I mounted a vent fitting on the bottom of the fuse that sticks out so a temporary line can be pushed on. Next, prior to starting the cold engine, using forceps, blow into the temporary line lightly and clamp off with the forceps creating a small positive pressure to the tank forcing fuel to the carb inlet. Normal starting procedures from there. Once running, remove the forceps releasing the pressure and remove the tubing and you're off to the races. My set up runs just fine in the air without any additional fuel pump assist. I've tested this method a number of times both cold and warm and it works nicely. One note though, just like with the electric pump procedure, one has to be extra cautious of flooding while choking.

Scott

IFLYBVM2

My Feedback: (360)

Does anyone have a spare Moki Blue box Ignition in good working order they would sell ?
I am in need of one please.
Text or call 843- 833-0059 anytime.
email me at [email protected]
thanks-Mike O.

rcguy5

Hey guys, I recently acquired a new 150 serial number 434. I plan on running it soon using a 26x16 prop, dominator at 30:1 for break in then 50:1 and seafoam at one ounce per gallon. It has the top hat ignition, cm6 plugs and a new fuel pump but would rather run it without the pump to keep it simple. I read about slowing servo speed a little along with leaning the low needle after break in to improve the firing of lower cylinder three at lower rpm. Anything I should look out for or add to my setup before running it?

I have a few more questions about the 150:

I’m curious what issues were fixed in later 150’s like mine from the earlier ones if any?

Do the u20m plugs make a difference for the number three misfire issue and if I do upgrade the ignition in the future should I and which would you go for, ch or rainbow and why?

I have tri flow for the rocker pivot points but not sure where else it’s needed?

I read about something else for the rods ends but can’t find that now, is it lithium grease for those?

Sorry about all the newbie questions, this thread is long and info keeps changing making it more diffficult to find all that I need, I appreciate any feedback.

Thanks, Mike

fatfreddy17

My Feedback: (43)

Mike,

Looks like you did some research! What you have looks good. I did upgrade my ignition to the Rainbow Tronics, The older ignition module were not always reliable. I run Denso plugs on all 5 cylinders.

I don't know the answer to what changed in production. If you contact Dr. Vogelsang he is very helpful.

One item you did not mention is rpms - keep an eye on the rpms. As the motor breaks in it will get stronger and rpms will increase. The 150's unwind in the air and lose rods around 5500 rpm. Per Dr. V you want to keep them under 5000 rpm on the ground.

Jeff

rcguy5

Thanks Jeff, I appreciate the reply. I’ll definitely keep it under 5000, eventually getting a solo or ramoser 26” prop for an fw190 it’s going in.

Anyone have experience with both ignitions, ch and rainbow? Which is the preferred one for these engines?

Mike

ultimate65

My Feedback: (116)

Hi;

I've been around many 3W and DA two stroke engines , 2 and 4 cylinders, and have many that I run on my 3D planes. However, I'm new to Moki. I recently purchased a used LA7 with a Moki 250. I believe the engine is 10 years old with the original black round ignition. I've installed a new 5200 mA 2-cell LiPo running a powerbox in-line regulator at 5.5volts output that powers the ignition.

I basically gutted the plane and installed new everything, including servos, electronics, fuel and air systems. I also rebuilt the carb with the kit provided by Dr. Gotz. It has a new APS fuel pump, running straight from the same 2 cell LiPo that powers the ignition. The pump is mixed to the throttle. 50% at idle and 100% at full throttle with a linear curve.

The engine starts fine every time. 3-4 flips with choke on, it pops, then 3-4 flips without choke. It idles all day at 780 RPMS, transitions great without hesitation to full throttle right around 4000 RPMs with an SEP 30x18 3-blade prop.The temperature at the exhaust output of each cylinder, without the cowl on, is in the 180-225 range. The Cowl is perfectly baffled with the manufacturer baffles and has a large exist under the cowl. I'm running Amsoil 2-Stroke Dominator, at 50:1 as recommended by Dr. Gotz.

I have had 3 flights on her. Every flight ends in a dead stick in the 3-4 minute flight time. Up until dead stick, the power is good, the engine sounds good and everything feels like it should. The last time I landed, I opened everything up and found air bubbles between the pump and the carb. This was after transporting the plane home after a 2 hour car ride, with the plane upside down in the truck. Not sure if the air bubbles existed right after the flight of if they could be due to heat or fuel being sucked back into the tank. I have run the pump with the fuel system on the bench and emptied three complete tanks of fuel, without seeing a single small bubble in the system. I have put the fuel tank under vacuum and pressure and have not seen any loss of vacuum or any type of fuel leak.

I'd like to hear all suggestions on how to eliminate all potential issues, and make this a reliable engine.

Thanks

GeorgiaFlyer

I know a lot of others on here have run the black top hat ignitions with no issues. But with everything else you have done which sounds right, the last thing I can think of would be to swap out the black top hat ignition with a new blue module. I bought a used plane a few years back, the first thing I did was replace the older black ignition with a new blue one. I have two Mokis running on the blue ignition modules with no issues.

ultimate65

My Feedback: (116)

Hi; Thanks for the reply. That is what I have been thinking and may still go that route. I was advised by Gotz not to replace it and it was a great ignition for this engine. I also see quite a few response here of people who do not have any issues with the black top hat ignition.

I have found some new information, since my last post. As stated, I have been supplying the ignition using a powerbox inline regulator to step down the voltage of a 2-cell LiIon 5200mA battery to 5.9 Volts. I just found a post on the powerbox forum with someone specifically asking a question as to whether the powerbox 5.9V regulator can be used with the Moki old style ignition. The response from powerbox was that the 5.5V regulator should be used, as the 5.9V "May cause interrupt engine running". Here's the link to the post https://forum.powerbox-systems.com/f...-spark-switch/

When I bought the plane, a 4 cell NIMH battery was installed and I also see that the MOKI manual states a 4Cell NiCad for the old style ignition.

I would appreciate others here confirming if they know this to be correct and how many are actually using the old black hat ignition successfully or if they have had to replace it to get the engine to run reliably.

Thanks

A343

My Feedback: (4)

hi Jaketab,
What % do you set for the APS with THR set at Lo and Hi ?

ultimate65

My Feedback: (116)

It would be interesting to get some feedback from the forum of the people using the black top hat, the blue and the rainbow ignitions and what kind of experience they have had. All comments would be appreciated.

rcguy5

A post I found in this thread shown below further confirms your suspicion about the input voltage. Looks like he may have used the tech aero ibec since it can do 5.3v to fix his problem. I myself will get a 5.5v sparkswitch for my new 150 I picked up recently.

ultimate65

My Feedback: (116)

Thank you Howie. That is great help. In trying to figure out these issues there are so many different suspects that may cause the same type of issue.

It would be great to hear from other flyers who have had good and bad experience with the old black hat ignition and whether you would recommend keeping it or change to the new blue or rainbow ignition. Thanks

tmac48

You will not get any better advise from anyone than you will get from Ian Howard!!

Jaketab

My Feedback: (2)

Don't know exactly as each radio may vary in numbers. Just play it by ear. Even at low output the pump will supply adequate fuel to the carb.

I have 2 - 250's. one is top hat and the other is newer blue box ignition. My older Moki with the top hat set closer to 6 volts runs smoother through the range then the newer Moki with the blue box.

srp55

My Feedback: (54)

Looking for any information concerning hand held starters used to start Moki 250cc radial, I've seen them used at many shows. I have a new MOKI 250 that gets a little ignorant at times, I've used my brother big Sullivan starter works great but are heavy. I'd like to find out what the smaller hand held starter using a LIPO battery are where I can get one. I have had both the 4.8v rated black top hat ignition on a older Moki 250 ran great on 4.8v. I purchased a BUSA 1/3 Stearmen it had a sweet running 215cc black top hat ignition also 4.8v ran great. The original owner explained to me it took 4 replacement black top ignitions before he was able toastart it. I also have a 250 with the blue box that's the one that is a little difficult to start at times, once started its run good still working thru the tuning phase. Any starter info would be appreciated.

Steve

Maxam

My Feedback: (62)

Concerning starters; the regular sullivan basic starter with the 1:4 reduction Miller unit on 4 cell lipo will start a moki 215/ 250 easily. What is nice is the speed is much more appropriate for the Moki's. The top hat ignitions have been reliable for me for ten years. I run them on their own circuit at 5.5 volts. Here is the catch; I have them isolated from engine heat located on the other side of the firewall. I do have the new blue ignition unit with my 257 and it is fine. -tom

srp55

My Feedback: (54)

Thanks Tom, I have been looking for a Miller R/C Products gear reduction they don't come available often. So the 4S battery delivers a good cranking speed for the Moki. I am trying to find the right set up for the ASP 380 electric pump that I'll using on my 250.I plan to put both the ignition and fuel pump on the same battery/power switch. Thanks Steve

David Gladwin

Another happy MOKI owner.

Started my 250 in my Sea Fury for first time today.

Followed instructions to letter, engine started and ran beautifully. Electric start is wonderful.

Great engine !

jraycut

My Feedback: (3)

Hi Mike,

I have a 150 w a CH ignition; on TopRC FW190. I bought the engine used and unsure how much time is on it. So far; ground runs and
In flight looks good. But I am going through a possible overheating issue when the cowl is on (yes it’s baffled w baffle ring from Gotz). Reliable low idle turning a Beila 26-16 FW three blade and 5” Tru Turn spinner.

After talking w Gotz, I am going to try a couple of his suggestions (a slightly smaller diameter spinner and a SEP three blade 25-17). Reason for the prop change is the FW prop does not have any blade coming out of the spinner to help push Air through The cowl; whereas the SEP does. A smaller spinner to allow more air in the cowl. I’m also going to open up the bottom of the cowl a little more; as well as making a small ‘lip’ on the bottom of the cowl opening to help draw air out. If all that don’t work; I do have a FW Fan to mount to the back of the spinner (like the full scale) I can try.

Does anyone have any pics they can share of how they successfully baffled their FW’s?

here is a video of ground run up; RPM was set at 4600 and idle around 1100.


Joe