dash3riprock

My Feedback: (10)

wingstrut

Gentlemen, I got a brain fart, I sent an e-mail to Amsoil Tech services and after sending several e-mails back and forth describing our radials in detail, this is what they came up with in the paragraph below.
I hope it helps with understanding about the oil that you use...........The only thing that bothers me is, Amsoil will not recommend any of their oils for manned aircraft. Is their oil not good enough? makes you wonder doesn't it.

If you still want to use a 50:1 mix ratio, I’d use the Interceptor oil instead of the Saber. The net result of using the Interceptor oil at 50:1 will be the same as using the Saber oil at 100:1. As you know, two cycle oil is burned with the gas. The oil is basically just a carrier for the additives needed to prevent premature wear. The concentration of anti wear additives in the oil is the same if the Saber is used at 100:1 as if the Interceptor is used at 50:1. You may be able to see one of the effects of this by comparing the viscosity of the two. You will find the Saber is quite a bit thicker. The “company� bases their mix ratio based on common two cycle oils, and has not done any testing on the AMSOIL product. We have safely recommended the 100:1 mix ratio since 1974, when the two cycle oil was first introduced.

wingstrut

Tom in Cincy

My Feedback: (16)

I bent a pushrod on a 250. Anyone know where to get one? ?Troy built?? The material seems really soft and non magnetic almost like brass but maybe stainless. Any idea what they get for one? I have tried calling TBM but all I get is a busy signal....
tnx

2walla

My Feedback: (10)

Tom- vogelsang can get them but you need to know how long you need- have your serial number handy as he may be able to help id the length.. they come in 3 or 4 lengths depending on how old the motor is.. The material looks to me to be hard brass that has been chrome plated.

BobH

My Feedback: (2)

Try AMR, they sell Moki's too

nine o nine

My Feedback: (1)

From whomever you buy a pushrod from just ask for the longest they may have on the shelf. They are easily trimmed to size by removing one hardened end by heating for a few seconds with a few seconds from a bernz-o-matic. Then a tug will take out the end piece.
Dremel and file to the size needed. A dab of epoxy before inserting the end piece and you're back in business. Mitch

Tom in Cincy

My Feedback: (16)

Thanks for all the tips. I was also considering picking up a foot of 4mm od tubing from McMaster-Carr. I still am not sure what material the hollow tube is made of. I straightened out the old pushrod pretty good but it still has a slight crook in it. It will work but I am going to replace it soon.

vfrank59

Not sure if I was lucky, but my engine came with an extra pushrod. Check the box the engine came in for a small clear ziplock. Good luck.
vern

samparfitt

My Feedback: (43)

ditto, my 250 also came with a spare pushrod (3 1/4" long) and a spark plug wrench when I purchased it new in 3/31/2009.

Concerning cutting the push rods shorter:
I was with Scott Prossen when his 150 lost a rod. He had a spare for his 250, removed one end, cut it to the proper length and the engine ran fine for the rest of the day.

Maxam

My Feedback: (62)

Everyone, My flying season ended with a 63 degree day and absolutely no wind on Wednesday. I decided to do a cleaning of the valve gear. I did this by standing the plane straight up with the engine shaft straight down on a plastic surface to protect it. I used good 'ol brake cleaner. With the engine straight down the cleaner would drip directly off the rockers and not get on the engine ignition, plugs and other parts. I would first spray the rockers themselves and a fair amount of black goo came off. Next I would bend the spray straw up and deep in between the rocker pivot and the valve spring, aiming directly at the spring and valve stem. A lot of black crap came out! I would wait about thirty seconds for the break cleaner to loosen more goo and hit the valve stem again. Brake cleaner totally dries everything so once it all evaporated I did a thorough oiling especially making sure the valve stem and spring got oil. This also makes the engine look brand new! I also used a soft toothbrush to remove dead bugs from the cylinders. Here is my engine after about 70 flights. -Tom

wingstrut

Thanks for the info Tom, The engine looks great

David Jackson

My Feedback: (15)

During my last flight, notice a change in the sound of the engine. Landed the plane and discovered that cylinder #four lost a pushrod and one of the four socket head screws attaching the cylinder to the engine was broken and the other three screws had loosened. Had to abort two landing attempts before finally getting the plane on the ground, so the plane was flown on just four cylinders for about a 2 minutes. Curious to know if anyone else had a similar problem with their Moki 250, and most importantly, did their engine require any repair?

Here is a video of the flight. At roughly the 5 1/2 minute point of the flight you can hear a difference in the sound of the motor. http://youtu.be/FEuWxiLT2Mk

Maxam

My Feedback: (62)

David, When I bought my engine the directions said to check the bolts on the engine periodically due to thermal expansion cycles. After my first flying session I checked the cylinder base bolts and sure enough, about half were not loose but not very tight either. I went around and tightened them all. After about 10 or 20 more flights, 2 or 3 were not so tight . After about 70 flights (look at my above valve cleaning post) all bolts were still tight. also the newer exhaust bolts have been improved. All needed tightening after a couple of flying sessions but I wanted to know if any were LOOSENING. I got a sharpie and marked the bolt drifting down to its matching pipe. If the bolt rotated the marks would no longer align. Amazingly the hot pipes would not erase/degrade the marks. They are staying put! Hope this helps. -Tom

Jaketab

My Feedback: (2)

David,

I guessing from the sound, the rod you dropped was on the intake side ??????
Your engine did not sound that bad with one down.
One day at the field, I dropped an exhaust pushrod upon start up - caused when the engine back flipped half turn. The engine made a popping sound with almost no power at all. It only ran for 15 seconds before I shut it down. The pushrod was on the ground under the engine. I reinstalled it and the engine ran fine.

J Tab

David Jackson

My Feedback: (15)

Thanks for the information. I do check valve clearance and the tightness of all engine nuts and bolts regularly. This is the first time in three years that I have ever experienced any problem with the Moki.

mick15

Which propeller were you using?

vfrank59

I have used Loctite 38653 222 Purple Low Strength Thread Locker for small screws. I wonder if going over the engine with this would prevent all the loosening. I may try it and see if this stops these issues.
Vern

David Jackson

My Feedback: (15)

Mick,

I was using the Beila 32x18 prop.

mick15

Yes David I’m not surprised to hear that……….

According to my calculations that engine was turning between 6800 and 7200 rpm that is assuming the tips of your 32-inch prop were almost supersonic!

I know it does sound arrogant to disagree with a factory with regard to its product recommendations but, myself and a significant number of other war bird flyers have proved these engines are much happier turning very large propellers. I have a 34x14 Biela on my La7 and a 34x12 Biela on my SeaFury both three bladers.

The most likely cause of your trouble is detonation brought about by overreving and the loss of a pushrod, a valve remaining shut at those revs will result in detonation. I am sure, if you watch Reno, Drag racing and tractor pulling you will be aware of the catastrophic damage that can be done to an engine by detonation. I am aware of two Moki 400s that have had cylinder assemblies blown clean off!

I also have to say David I was a bit surprised to see how long it took you to stop an engine that was obviously in considerable distress.

So, for the future I recommend you prop the engine to the high 3000s on the ground which should give you high 4000s in the air coupled with the huge torque of these motors should in my view be more than adequate. (A scale Corsair with a scale speed of 700mph doesn’t look right anyway!)

m

Tom in Cincy

My Feedback: (16)

Just a FYI. If you need to replace a damaged pushrod McMaster-Carr sells a stainless steel tube pt no. 50415K158 that is the proper size. About $12 for .5 meter length. The factory material is indeed brass so I hope the harder material (the stainless steel) is ok for the application. Vogelsang Aeroscale was out of stock....
tp

oy4310

Hi there. I'm making my Beaver ready for next season with a new Moki 150. Because there isn't enough height during take off when the plane "rises" there is no room for a 2 blade 26x16.
Biela is also recomend a 4 blade 23 x 14. Have any try that. Is't a really expensive one, so it would be nice to know if this one is working well.

Best Christian

kipuetz

Hi everybody,I need some help,
does anybody know the compression pressure of our engines,Moki 150 ect.
Have justfoundnr.3 showed less colour on the plug then the other 4
cylinders. New plug makes no difference,also idles a little rough.
Tappet gap is correct, compression test next.
I would like to know what pressureI'm aiming for,
Regards,Karl-Heinz.

nine o nine

My Feedback: (1)

Is there a Moki owner here or who knows of a person with enough electronics experience know how to troubleshoot my ignition module? It doesn't light up one spark plug on my 215. I've substituted a friends module and the engine runs fine so I know it's not coils, voltage, wire shorts or the like....only the module. There's absolutely no help from the manufacturer who probably gets them from a secret vendor. Thanks for any help, Mitch

Maxam

My Feedback: (62)

Mitch, I have heard from people on this thread way back that discovered the "microphone" plug that plugs into the module had a broken wire due to vibration. A quick solder job fixed it. Or maybe one of the contacts deep in the plug got bent outwards. Now maybe with an OHM meter you could measure the resistance from each wire. You would need to find out which wire was ground assuming there are six wires, one ground and 5 others matching their respective coils. I hope this gives you food for thought anyway. -Tom