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Engine Doctor

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Engine Doctor last won the day on March 21

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  1. Your correct . I missed that . Basic principles still apply ie decent tools , remove congealed oil,heat etc.
  2. Hi Andy . To make a head shim from Litho you dont really need a compass cutter. Use the cylinder to mark the litho plate and then cut with some small curved scissors. The internal hole can be cut as follows . Make a sharp scribing tool from a piece of thick piano wire say 1/8 inch . Sharpen to a really fine point and harden then temper slightly. Now press the top of the cylinder down onto your piece of litho plate and scribe arond the inside a few times and also mark around the outside . Remove the cylinder and carefully bend the litho where you have scribed . It will usually snap quite easily. If it doesn't then finish with a new sharp scalpel . Now you have the hole cut, anneal the rest of the Litho plate and cut out the shim with your scissors . Should only take a few minutes .
  3. Hi first check theat the hex recess in the screw is clear of hardened castor . They can fill with old castor and this stop an allen key from fitting properly. If unsure dig out with a sharp tool first. Only use decent HSS allen drivers for these screws as the cheapo allen keys that often come with engines are generally rubbish and will round off and in the process will round the socket in the screw . Heat is a friend when it comes to stuck theads . An oven . hot air gun or if you know what your doing a blowlamp can be used . For stubborn screws fit a HSS allen driver and give it a sharp tap with a small hammer .
  4. They were very popular some years ago and fine if you pre drill a guide hole for the screw to fit into. Make sure the guide hole is wide enough to accommodate the center part of the screw so that the threaded part can cut into the mounting material. The downsideof using ST screws is that unless the guide hole is not central to the engine mounting hole then there is a real risk of breaking the engine mount lug. Provide you get the ST screws central to the engine mounting holes then they will perfectly fine and in my experience have never come loose . Personally I now drill and tap a thread in a mount or use cap screws and bolts but that's just my choice.
  5. Yes should have a thin ali head shim/ gasket on the OS 20 . If the recess in the head is very shiny then it has a gasket wedged in there. Removing the gasket and annealing will often cure a slight leak unless the head has been tightened down unevenly or by a gorilla and distorted. If that's the case then it got to be replaced or if you have a scrap liner ground to a good fit. Over the years I have seen engines with all sorts of "mods" and gaskets fitted . One was a Frog 500 with a head gasket cut from a bicycle inner tube ! And the Frog doesn't need a gasket . Please don't waste time with paper gasket on head. Cut one from litho and annealed before fitting.
  6. A friend had the same problem with his charger. He gave me the batteries and I tried them on my Imax 6 , they charged with no issues ? Are some makes of charger over sensitive?
  7. Yes . Take responsibility for your own actions ,both model owner and driver. Not taking responsibility for your own actions seems to be a growing problem these days . However there are two sides to every situation. If the car was driving into the car park moving forward then one would expect the driver to see any obstacle or model or person in their path and brake or take avoiding action, as you would be expected to do while driving on the road. Just because your in a car park you are not excused your obligations while driving. If cars are not allowed onto the flying field and have to be loaded and unloaded in the car park then it's reasonable to expect models to be in that area and driver should have been more careful. If on the other hand the model was placed behind a parked vehicle and subsequently run over when it reversed then its probably the model owners fault although the driver of the car still has the obligation to ensure the way is clear. As far as the club is concerned it should be sorted between the two people involved amicably without interfering with the smooth running of the club. Ask the model owner to contact the BMFA to se if the insurance will cover this . If either members cause the smooth running of the club to be seriously disrupted then give the offender/s a verbal warning . If they continue causing disquiet then issue a written warning. If they still persist in upsetting the club then suspended or expel them from the club. If your club constitution doesn't have any clauses to deal with such situations then it's time to make an ammendment at your next AGM,
  8. I'd work from bottom up covering the fuselage side and possibly the curved part of the cockpit side then the vertical stable. I'd try to do it in two parts per side although three may be needed. Youll have to stuck it and see. Allow 1/4 inch overlaps or 6 mm in new money. Show us how you get on ?
  9. A couple of garages locally are charging £2.07 for diesel and petrol is 10p cheaper. The supermarkets are currently a bit cheaper at £1.87 for diesel and again petrol 10p cheaper. HMG love it as we are still paying VAT on it and on the fuel duty.
  10. Have you checked the display settings on your device ? Light setting gives a light background with black text while the dark view setting gives the dark background with white text . Worth checking as possibly the banner etc is not compatible with a dark setting.
  11. I have one fitted to my Habu . They were cast in a light alloy with a rubber end that could be moved to alter the tone of the whistle. It only works at certain speeds though ie upper mid range . To be honest they did sound that good and become annoying. I did have another one somewhere in my workshop, if I find it I will let You know and you can have it. E.D.
  12. The Solarfilm website updated 2022 is still showing it as available ? Might be worth a call ?
  13. If you buy a optical tacho be aware that they will be affected by artificial light such as fluorescent tubes if testing indoors.will show an error or peculiar reading as they will read frequency of the light source. Don't know how they react with LED lighting. Use in day light and you will get correct reading . I obtained one many years ago and it sat in its box for most of that time only coming out for tuning small engines like Cox's when a tacho is handy.
  14. You might need a plastic primer to increase adhesion .Its usually clear then follow with a coat of normal primer for the paint your using. Be aware any paints add weight especially at the rear of the model affecting CG . You can buy aerosols of plastic primer from car paint suppliers or Halford etc. Test on a small area first before committing to the whole airframe. Adhesion enhancers like the old Solarfilm Prymol only work on the original Solarfilm made from Polypropelene and won't work on the newer polyester coverings . The auto plastic primer works on a range of plastics used in car manufacture .
  15. That glow clip you have fitted is a large heat sink and will try to cool the plug. Try a lighter commercial type What fuel are you using. Too much oil will puddle into the plug when inverted. Try a lower oil content say 15 %. Still plenty for the engine. When you stripped send cleaned it did you make sure that crankcase compression is good ? Any leaks will cause erratic running. Is cylinder compression good ? If piston ring is worn and compression is low this can also add to erratic running. Hope you get it sorted.
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