Clarence Lee’s Blog

Engine cleaning: DON’T use this product!

Jul 07, 2011 1 Comment

Q: I have a 180 Saito that I ran for a 1/2 gallon of fuel and decided to go with a larger engine. It had some brown residue around the muffler port, thinking I would clean it up I sprayed oven cleaner on it. Now it is a dull gray and looks 100 years old. My [...]

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O.S. Needle-valve replacement

Jun 23, 2011 2 Comments

  With regards to the O.S. pumper engines, I have the original series O.S. 120 surpass with pump and c12 carb. this engine was recently involved in a dispute with the ground about 40 yards from the runway, and well, the plane lost the argument. But the engine survived, kind of. The needle broke off along [...]

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Gas engines & after-run oil

Jun 23, 2011 No Comments

Q: I own a Ge20 ei (Zenoah G200PU) gas engine, model X374320000.  I ran it a few times and it was OK.  Then I set it aside for 6-8 months and then it would not run. I discovered that the carburetor fuel metering/diaphragm was no longer flexible.  So I got a repair kit and replaced [...]

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Counter-rotating props

Jun 13, 2011 No Comments

Hi, I have a question regarding 2-stoke model aircraft engines,  and multi engine aircarft. Can 2-stroke engine be made to run ccw and just reverse the mounting of the prop? Why do I ask?…aircraft like the P-38 had counter rotating engines, which I assume was to counter the two engine’s torque. Also, why wasn’t this application used in more [...]

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Inverted 4-stroke questions

Jun 06, 2011 No Comments

Mr. Lee, I have been a long term reader and thank you so much for sharing your wealth of knowledge!      My question: I have installed a Thunder Tiger 91 4 stroke in a P-47 with the head at about 7 o’clock position. (Not quite totally inverted). So now the drain nipple on the bottom [...]

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Running lean in flight

May 27, 2011 1 Comment

Hi, I have a new  O.S. Surpass FS 120S III and the engine looks good in low idle but when I go to the air the engine become lean and the max revolutions are to low.  I tried any needle adjustment but the engine don’t have  enough power. Regards, Carlos V., Venezuela Dear Sr. V., [...]

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Inverted issues

May 22, 2011 2 Comments

Clarence,     I have a OS BGX-1 mounted inverted in a one-fifth scale Pica P-40. I am using a J-Tec muffler.This engine is very hard to start. I usually have to turn the plane over, place in a cradle, then it starts, by hand, easily. I then shut it down, put the plane back on its [...]

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Coleman fuel

May 16, 2011 No Comments

I tried Colman fuel on my Fuji BT-32B and my Zenoah G62 with C & H Electronic Ignition. Both engines ran fine with the Colman fuel and Evolution Synthetic oil mixed 35:1. I have on the BT-32B a relay kill switch that shorts the magneto and on the Zenoah G62 I have a electronic kill [...]

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clarencel

About the author

World-famous model airplane engine expert, he first started writing his “Engine Clinic” column in 1969. He built his first model at the age of 7 and he started flying powered model aircraft in 1937. Clarence became interested in RC in 1956 and designed and built his first Lee .45 RC engine in 1959. His vast knowledge has made him one of the hobby’s most valuable assets.
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