RE: New Zenoah GT-80 misfire
That could be part of my problem. I will have to check further to be sure. Thank you for your information.....Ron
Posted on: 5/19/2013 9:10 AM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11516046

RE: New Zenoah GT-80 misfire
Hey folks! I just noticed that my GT-80 doesn't have a gasket between the carb and the phenolic / plastic spacer, there is one between the spacer and the intake manifold. Does anyone else have this on their GT-80? I have tried to find a decent parts breakdown but couldn't find one good enough to verify this. At one site they listed two gaskets at another they listed one gasket but no views. Ron
Posted on: 5/19/2013 4:09 AM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11515832

RE: MOKI RADIAL Care and Maintenence
I wouldn't doubt it, Marvel mystery oil is great stuff! It's basically automatic transmission oil with different additives. I thought Amsoil was going to eliminate excess build up of sludge, carbon, and all this other crudd. Now it isn't working and causing a problem that requires an engine repair. Is there any proof besides that one report stating that Amsoil is causing carbon build up that could possibly cause engine problems. The manufacturer states that Amsoil will burn clean and eliminate any build up of deposits, then I look at my exhaust and wonder why it's coming out black and the black carbon deposits on my spark plugs make me wonder who is pulling whose leg, my dinosaur oil did the same thing, now where is the improvement. I haven't used Amsoil long enough to make an educated decision on whether it is the right stuff to use I know that Redline is a synthetic, what type of redline are you guys using, they make a lot of different ones, probably differs mainly from the additives they put in it. I would like to try it and see if I still get the buildup of carbon on the plugs. Thanks for the info guys................Ron Waco brother #216
Posted on: 5/18/2013 2:36 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11515367

RE: New Zenoah GT-80 misfire
The engine loosened back up, I don't understand this, but I'm breaking out the locktite and safety wire, I will fix that sucker. I really appreciate how you guys jumped right in to help, fantastic information.......Thank you again................Ron
Posted on: 5/18/2013 1:24 PM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11515308

RE: New Zenoah GT-80 misfire
That is very interesting, lower the compression and change the timing, could work. I think I found my misfire, I hate to admit this but my engine was loose, I have never had an engine come loose before. I believe it could have been creating RF frequencies that could possibly have been interfering with my electronic engine cut off module. I came to this conclusion after tightening the engine back down and flying the plane there were no misfires actually I received comments on how smooth the engine ran. Thanks tony for that info
Posted on: 5/18/2013 12:51 PM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11515275

RE: New Zenoah GT-80 misfire
The engine is a Zenoah GT-80 swinging a Xoar 26x8 sabre WW1 style prop, Exxon regular gasoline mixed with Amsoil dominator 40 to 1. I ran the engine without the cowl so I could adjust the carb, there is ducting around the cylinders. I measured the temperature after running the engine for four minutes at half throttle on the ground, I did not fly. I used a Fluke 561 IR Thermometer at approximately 18 inches from the cylinders I pointed the IR beam at the center of the cylinder half way between the crankcase and the spark plug. I did not point it at the fins. I could not get a cyl. temp at the rear of the engine because of obstructions. Viewing from the cockpit the left cyl. temp was 235 degrees Fahrenheit the right cyl was 260 degrees Fahrenheit. I ran the engine at various rpm's for another four minutes on the ground and the temperature remained the same. The temperature outside was a steamy 89 degrees here in florida. Thank you for time,.....Ron
Posted on: 5/17/2013 6:00 PM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11514734

RE: New Zenoah GT-80 misfire
K-Bob, do you have a recommendation for a transmitter operated engine cut off? Thank you for your time..............Ron
Posted on: 5/17/2013 5:44 PM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11514718

RE: New Zenoah GT-80 misfire
Sorry guys, I failed to mention that it is a magneto Gt-80 swinging a 26 x 8 prop. I have correctly set the needles at least six times going from just right to slightly rich. set low end to maximum rpm then backing off about 300 rpm, high end same way. I have set the high end rich and the low end lean. low end rich and high end rich and vise versa. I may try to disconnect the engine shut off module to eliminate that part, I bought it used. It seemed to change the interval when I changed plugs, that is why I suspected the one cylinder running hotter may be the culprit. Is 260 degrees too hot.? Thank you fellas for the help..........Ron
Posted on: 5/17/2013 2:11 PM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11514539

New Zenoah GT-80 misfire
Gentlemen, I have new Zenoah GT-80 that starts and runs great, but as I am flying at half or full throttle I hear a skip in the engine about every thirty seconds, I replaced the Champion RCJ7Y's and they gave me Champion 5843, they claimed these were the new easier start plugs. Well, It was miss-firing every two seconds, it sounded like the ignition system was shorted. I took those out and replaced with NGK BPMR7A which is the replacement for the Champions. It ran better but still had the skip, but now it is about a two minutes apart. I replumbed the fuel tank three times, I have soldered on barbs and ty-wraps on all the fuel lines inside and out of the tank, when running the engine the fuel flows through the lines without and signs of bubbles foam or anything else. I took several temperature reading of the cylinders, the cyl on the left as you are sitting in the cockpit runs about 235 deg., the other cylinder runs 260 deg. The cooler running cyl. is further back from the cowl, maybe it is getting air more efficiently, just guessing. Is this temperature too high and maybe causing the plug to over heat causing the miss-fire? I haven't tried using a colder plug in this cylinder yet. I am using Exxon regular mixed with Amsoil Dominator at 40 to1. I am also using a 42 percent ignition cut off module. Thank you for any ideas, it has me stumped,...........Ron "the temperatures were taken on the ground without the cowl, I have air ducts around the cylinders.
Posted on: 5/17/2013 11:16 AM by Author "wingstrut" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11514391

RE: MOKI RADIAL Care and Maintenence
[size=3][/size][size=4][/size]I'm using 4.8 volt 3000 mah ni-cad batteries.
Posted on: 8/13/2012 12:50 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11191898

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Jpate147, The plugs gap at .012 to .015 of an inch, that is what my owners spec. sheet said for the CM-6's
Posted on: 7/20/2012 11:49 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11162649

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Another company came out with that U grooved ground electrode many years ago and it didn't seem to work then, maybe Denso got it right this time. As far as increasing the heat range in an engine, you are asking for major failures if you don't know what you are doing. But they listed that the U groove created a larger more concentrated ball of fire that helps eliminate fouling, not a hotter plug, hope it works.............Thanks for the input Steve.................Ron Let us know what you think after a few more flights.
Posted on: 7/18/2012 4:35 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11160413

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Steve, That is what I came up with, that the U-20 is a direct replacement for the CM-6, I was trying to find out if the Denso plug may be made out of Iridium which may allow it to be considered a (super ignitable plug), and one that would not deteriorate, I studied their plug chart and couldn't find that it was. Why chase after a plug that the company discontinued, lets hope that NGK doesn't discontinue their CM-6. And you are correct, the number is the heat range, the letter designations tell the thread size, length of thread and basically the dimensions and certain features of the plug. The CM-6 and the U-20 are the same plug according to Denso's chart..............Ron
Posted on: 7/18/2012 5:04 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11159669

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]It sounds like the plugs may be IRIDIUM, if that is the case then the price is about right.
Posted on: 7/14/2012 4:37 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11155393

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Dave, you may want to contact I believe AMR is the distributor in Canada, they may be able to steer you in the right direction....Ron
Posted on: 6/26/2012 4:55 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11133015

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Dave, I was just wondering, the EP gear oil that you drained out, how long was that oil in the engine?. By the way that info on the EP gear oil having additives that are corrosive to yellow metal came directly from the oil company, in case anyone has doubts. Sounds like lack of lube. The reason for lubrication is to keep metal from touching metal so you don't have wear. I don't have that much running on my 215, I pulled a lifter and it had grease on the end and no signs of wear. I have the original grease in it and as best I can tell it is one of the newer engines. Sorry not much help.....Ron
Posted on: 6/26/2012 2:40 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11132857

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Thanks Mick and Jaketab, I just got an idea to solve this whole dilema,... drill a small hole in top of the forward housing, then install a zerk fitting in the lower front housing, then before every day of flying just give it a couple of pumps of grease or until it comes out the hole in the top.........Problem solved. Ha!Ha! I will go away now.....Ron
Posted on: 6/24/2012 8:05 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11129750

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Mick, I totally agree with you, and I understand that you have the older Moki engines that had the grease problem, you have the correct solution. I am wondering if the so called new grease will flow at low temperature to migrate to the required areas, the reason I am wondering is because the stuff seems to get by the carb pump piston into the festo tube, so I'm assuming the grease must be liquifying to some extent.......Maybe not! The only way to know is to get some of the LGHP 2/1 grease and warm it up, if it doesn't flow then I will add oil......Ron I am not disagreeing with anyone, I am trying to bring up things we need to consider and possibly find an answer to before we change anything. These are wonderful engines and quite an investment so I think we need to investigate completely before reacting. I am sure everyone will agree our main problem is the lack of instructions and information from the factory!!!!!!
Posted on: 6/24/2012 4:38 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11129574

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Hey fellas, I thought I should mention that gear oil with GL-5 rating which has EP additives is corrosive to yellow metals, such as bronze and brass. It looks like the Moki has yellow metal bushings in it so be careful if you select a gear oil because you could be doing more harm than good. Just thought I would pass this info along..........Ron I hope someone will tell us how to tell the difference between the old 215/250's and the new 215/250's so we know which grease we have in the front housing. Thanks for all the support on this subject.
Posted on: 6/23/2012 5:10 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11129135

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Growler84, thanks for the info that will save me a lot of work, as I stated earlier, I remove the pushrods and lube the sockets and lube everything you stated but I also lube the lifters. Now the big question, ..How do you tell the new 215/250 engines from the old 215/250 ones?
Posted on: 6/21/2012 3:57 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11127052

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Steve, Thanks for the pictures and detailed instructions, that was really nice of you to take the time to do that. All the Moki brotherhood will appreciate that one. I am going to do some research and see what type of high pressure lubes are available that may work in our application and will post what I find shortly, maybe the grease in there right now is flowing after it gets hot and doing the job, I doubt it!!!!.............Thanks again........Ron
Posted on: 6/20/2012 6:24 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11124961

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Detlef, Of course I knew that, I just wasn't thinking at that moment,........you know,...... it's called old age,....I am actually embarrassed for asking that question......I was a master automotive machinist for many years, it upsets me when I ask questions that I know, if I just think for a minute. I agree, the electric pump is the way to go, and I am definitely going to remove my mechanical pump and put the heavy flowing stuff in. I think I will also come up with a filtered vent for the gear case, I'm sure it's not needed but it will be a great conversation piece. Now I will get to see what is inside this masterpiece. Thank you for your expertise and time it is realy appreciated......Ron
Posted on: 6/19/2012 5:52 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11124469

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Detlef, Do you have a problem with the oil/grease coming out of the Festo pump especialy when you fly inverted. I also have another question, If you remove the pumps rod and piston why couldn't you just plug the hole, that section is not part of the crankcase so there shouldn't be a need for venting.....Or is there?............Obviously you will need an electric pump to feed fuel to the carb....Thank you for your time....Ron
Posted on: 6/19/2012 4:17 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11123467

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Brass or metal gears, it doesn't matter when they are not lubricated. I figured the lifters would be the first to go as they get no lube at all, the gear oil would take care of all that. I remember that post about the gear oil and someone jumped in to say that it was not recomended. Thanks Mick, I may dismantle my 215 and use gear oil. I have been wanting to remove that carb pump anyway. What happens when you fly inverted? do you get a lot of oil coming out of where the pulse generator was.
Posted on: 6/15/2012 4:30 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11119616

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Mick, I agree with you, grease should never be used in a gearbox unless you want to replace the gearbox in a few years. Once the gears push the grease to one side that is where the grease will stay,it will not flow back onto the gears. Mick would a few cc's of 150 wt. gear oil in with the grease cause the grease to liquify enough to flow.......Ron
Posted on: 6/15/2012 10:12 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11119278

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]In regards to lubrication, I rotate the crank until a cyl is at top center on compression and both valves are closed, then I press down on the valve end of the rocker and remove the pushrod then I can completely lube both ends of the pushrod and work the rocker back and forth to distribute the oil, I also lube the lifters and valve stem. Then I proceed to do that to the additional cyls until I get them all. I think I will go with the tri-flow that sounds a lot easier and I will look into the Sea Foam to help keep the carbon away...................Thanks Jake, Tim and Daryll
Posted on: 6/11/2012 5:01 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11114905

RE: MOKI RADIAL Care and Maintenence
[size=3][/size]Jaketab, Something interfered with the natural function of the valve train, here is a list valve springs weak from overheating not allowing the valve to return to its seat fast enough and the piston contacting the valve. valve lifter stuck valve stuck Valve seat coming loose. overrevving the engine I don't have a breakdown of the moki engine so I can't tell if valve and piston contact is even possible, but if it is you need to check the compression on that cyl to see if any damage to the valve or piston has happened. You need to remove all the other spark plugs to make it easier to check that one cyl. Turn the engine over slowly bringing that cyl up on the compression stroke and listen, you may be able to hear the valve leaking air into the exhaust manifold. If you have compression and it seems to hold then you may have luck on your side. Obviously if you have a leak and can't hold compression on that cyl. then it needs to come apart. If the valve has contacted the piston it could have pinched the ring in the ring land and this would soon destroy the cyl. if not replaced. And obviously the valve may be bent. If everything checks out alright, I don't know how fast you are turning this engine, but everytime I see a Moki on a WWII warbird they are screaming across the sky. and I just cringe waiting for the cylinders to leave the crankcase...............These engines turn big props at low rpm's, there are too many moving parts to be turning these things like two strokes. Sorry for the extra comments, but we need to run these engines in the correct range, I put all the blame on the manufacturer for the poor support and lack of operating instructions. As long as you are using that mixture and the cyls. are firing and the temp is up I don't think you have a carbon problem. Good Luck, .........Ron Let us know what you find.
Posted on: 6/11/2012 6:01 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11114202

RE: MOKI RADIAL Care and Maintenence
[size=2][/size]Whit, you are correct, isn't it great all the neat things radials can be used for.
Posted on: 5/27/2012 12:24 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11096390

RE: MOKI RADIAL Care and Maintenence
[size=2][/size]Heinz, I believe most of the old Sikorsky units used radials like the H-19 and UH-34D's , I just thought someone out there might be thinking of a radial for a heli, that would be a neat helicopter............Ron
Posted on: 5/27/2012 11:35 AM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11096340

RE: MOKI RADIAL Care and Maintenence
[size=2][/size]Heinz, I'm sure someone is working on that, I'm wondering if the Helicopter boys have come up with a use for one yet.?..............Ron
Posted on: 5/26/2012 12:54 PM by Author "wingstrut" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11095471