Engine Doctor

H Stephen . i believe giant cod has some  glass fibre wheel spats on his website at reasonable price . Not sure wether they still on there or price  but worth a look.   E.D.

Dont waste your time and money as you wont get the same sort of power from the engine with petrol . You will also have to keep a high oil ratio as the engine will have plain bronze big and little end bearings that will sieze if you cut down to normal petroil mixes . Try some of Southern modelcraft fuel . Fully synthetic 20% nitro costs about £15 a gallon and unlike the stuff with fancy coloured oil etc . Good luck E.D

Hello Herri I run my petrol engines on 4 cell Nimh packs at 2000 mah capacity . They will work all day without recharging . I have'nt checked the current draw on the ignition unit but it cant be very high  as recharge only takes about 7 or 800 mah. Beware of any high voltage back surge from the ignition unit doesent damage your regulator as it did when I I tried to incorperate an LED into the ignition circuit to indicate power on . As soon as the motor started it blew the LED . Its worth checking out before committing to the air and possible engine failure.   E.D

It sounds  a bit like the saga with OS 32sx engines and the chrome/nickel plating peeling off the cylinder . At the time ( about 6or seven years ago) Ripmax eventually rebuilt the engines without charge . I have just used one that was rebuilt and unused in my cougar and its blown after a couple of hours use !  Engine is  not worth repairing now but a 200 fs is  a seriuos bit of money . Hope you get one that lasts OK .   E.D 

Hello Alan . Yes it was tempting but have quite a few bits already so thought I should use them . EDF is not my main interest but is addictive so I have to make sure I dont get pulled in too far.   Phil 

Just a warning re the Pond shop epoxy . It great if you want "the never setting variety" This gives you ages to position  the job . Geuss howI know . I have bought some in the past and its been excellent for keeping in the flight box but latest lot is rubbish . Beware ! E.D. Phil

After reading your posting Alan I had a look at the Overlander Website and placed an order and have just received my F 16  . Excellent bit of kit with retracts etc  delivered for £52 !   I was amazed at the speed of delivery as I ordered in the afternoon and it was delivered early the next morning and only £3-00 postage . I dont know how the retracts will stand up to the grass strip but the kit is cheap enough to play with . I have just upgraded a Kyosho T-33 kit I found at a bring and buy with a D/F bought from Hong Kong with a 4s lipo .It has really brought it to life  with proper jet like vertical performance . Very unlike the original back in the 90's gasping for air .  I plan to fit a similar D/F in the F16 or possibly go to a 5s set up as the motor is supposedly capable  . No rush still enjoying the T33 . Thanks for the Bargain Tip.   E.D Phil

We all hear of the bad experiences but just had a good one with Overlander. I ordered a model that was being sold at half price rrp,thats  good. Then the postage was really cheap  £3-00 for a large model box , thats really good . Then it was delivered at 9-30 the next morning ! Thats excellent .

Hello Eric .I havent noticed it on e-bay but Pica kits IMO build into good looking models that fly well  but are heavy by modern standars.The materials supplied are also poor with rubbish grade Ply and furniture grade balsa .If your not careful then the back end becomes very heavy.The hardware supplied is also below par . If youre willing to replace said items then a reasonable model can be built . I have built the Pica  P40 War-Hawk for a club mate and am currently sorting a Pica 1/5 Mustang that I bought part built. I now wish I had started from scratch with another kit/ plan . I have just finished a DB hurricane for a mate and would recomend that route . The DB kits have been re-designed with bult up wings instead of heavy foam . Had they had a Mustang in the range I would have tried it .As always with E-bay or any auction "Buyer Beware" 

Hello Ed . Do you know any one with a lathe  ? If so get them to tun the end of the spinner nut (engine end) to a taper ,similar toto the lock nut  . Then pue a split in it with a hack saw agin copying the original lock nut . Use this and put original  lock nut away for future use  . Simples  PS dont be tempted to use a plastic spinner on a four stroke .. Sooner or later it wil compress and let the prop slip or worse fly off , Ouch . Hope it helps E.D.

Self tappers are fine as said previously ,in Glass reinforced mounts . Make sure to use the correct size screws as some of the horrors Ive seen have bee caused by using too big a  screw. Drill a  pilot hole, making sure its big enough  and pre thread them before fitting engine by screwing the screw in and out . Do this to be sure that the screw will tighten ok without getting so tight that its head shears off ; this will also enable the screw to go in straight. I have been asked many time to repair engine mounting lugsthat have been broken by using too big screw or screws going in at funny angle . Tip to mark the mount accurately for drilling. Hold engine in the mount making sure its in the correct poition. Next get a piece of  piano wire that is an easy fit through the engine mounting lug and grind to a point . Hold in some pliers and heat pointed end with gas lamp to red hot. Now slide through engine lug and int the glass/nylon mount this leaves a marker  hole ready to drill out to the correct size pilot for the screws. Simples   E.D

hello Rob . You could also try Southern Model Craft . They are based at Tonbridge which is a fair bit nearer and will save a couple of hours travelling .They make all types of glow fuel from cheap castor based straight to fully synthetic high nitro . Google for the contact details and give them a ring . Suggest 10% Hi-lube for your fourstroke . It contains 20% synthetic oil , ideal for running in.

Medway MFC invite you to a            Swapmeet/Bootsale       followed by a fly-in At their Stickfast Lane site Near Iwade Sittingbourne   kent Sunday 8th August  starts at 10 am £5-00 a boot  £1 entry Modelling related items only Anyone wishing to fly must have proof of insurance Will be sign posted from McDonalds at Bobbing And from Iwade Village center Just off A249  For further details contact Phil on 01795-476535 or Colin on 01634-317187 Edited By Engine Doctor on 19/07/2010 22:10:28

Just a small problem that occured with one of my petrol engines and gave all the indication that the CDI unit was faulty . The engine had been removed for some work and then started to play up . The fault was eventually traced to some metal filings/dust that had been atracted to the sensor magnet . Quickly removed with some masking tape and problem sorted. worth a check and it wont cost . As said in previous post , check the plug . The cheap chinese plus provided can be very poor . replace with an NGK equivalent .As said they appear to spark in open air but uder compression the spark will take the shortests route and that can be straight to earth . Main thing is to try just one thing at a time starting with the cheapest first. My Crrc 45cc had a duff cdi when new wich when replaced run the motor very well until it gave up mechanically. The 50cc seems a much better produced unit than the early models . I would have thought that the electrics should have been  improved as well  . Good luck E.D

Helo Bob. I must agree with A.A.Barry . Check the baerings before you attempt to start up. If the bearings in your engine are corroded then they could (and probably will) start to break up when started . Even if the actual bearing doesn't break up the bits of rust and debris will act like a grinding paste and damage the cylider etc wrecking the rest of the engine . Four stroke ,while not as bad as two strokes do suffer from bearing corrosion while stored. Its far cheaper to fit new bearings(typically £15-£20) than to shell out for a new engine. Tell tale signs are a notchy feel as you turn the engine over and/or up and down play at the crank web .you feel if there is any wear in the bearings by fitting the engine in a stand or model then fit a prop. Now turn the prop to vertical and hold at the tips now try to rock the tips back and forwards (to and from the engine) any play in the bearings will be felt at a click. in extreme cases you can see the movement where the prop drive meets the crankcase  .Dont forget the camshaft bearings as well . These dont get much lubrication on the older fourstokes . The play in all the bearings adds up affects the timing and the performance of the engine . Good luck , hope you get in the air soon.   E.D Edited By Engine Doctor on 29/06/2010 10:01:52

If snake are tight then there must be a cause and lubrication wont cure it . It may ease it for a whil but it will tighten up again. Make sure the iner snake is made for the outer. Different makes will not fit one another  Try replacing the inner snake or if the outer is damaged replace the whole thing. Too tight a bend will cause sticking and sticking will cause the servo to stall ,greatly increasing the consumption from and duration of the battery. Better safe than sorry  Fix fault or replace  then try the lube and it will be even better. E.D.

Hello twilightflyer . I think you'll find most Saito engines oose quality . The older engines are very economical to run ,very torquey and are reasonably quiet .The later high lift cam series are much more powerful and as expected use more fuel .They are also fitted with a muffler that really muffles !. The 82 being a real powerhouse (superb in a wot four) .If looked after they will give years of reliable service .IMO they are well worth the little extra cost .

Hello Clive .Try to find out from Just engines the "NGK" equivalent  plug number . The cheap and cheerful chinese plugs supplied with most engines are prone to breaking down , causing eratic running and difficult starting. Once you know the NGK number ,most car spares factors will be able to order you one at a sensible price,usually a lot less than model suppliers .

Hello VA . To calculate the offset of the mounting holes  draw a line the same lenght as from the firewall to the back of the spinner /front of prop driver and add 3mm for running clearance( engine lenght) . Using a protractor from the front end   mark 2 deg and extend this to the end of your engine lenght line. The distance between the two will give you your offset for the mounting holes . If the model is designed for this size of engine you should have plenty of room . The engine  can then be mounted directly to the firewall/flat surface  without the chance of distorting the crankcase with packing washers under the stand offs . To prevent the nuts and studs pulling through or crushing  the fire wall  I make washers out of 2p peices drilled to the correct size . I dont know wether its legal or not but its cheaper than  buying washers . lets see some more pics as the build progress ?   Good luck   E.D.Edited By Engine Doctor on 22/06/2010 11:21:44

Hello Gazza . Air bubbles can also be caused by air being sucked in through the needle valve . Remedy is to fit a new "o" ring. Faults in the fuel pipes in the tank will only become evident when the fuel level get down to about half a tank and the pipes inside the tank are exposed to air. Does youre engine run ok with a completely full tank? If so it is more than likely to be the pipes leaking air.   Provided the fuel lines and pipes are OK check the following .Bubbles in the fuel can also be caused by vibration . This causes the fuel to foam = bubbles = air = weak fuel mix= dead stick. Have you  checked  the prop/ spinner for balance ? If thats ok , Is your tank mounted in foam ? Foam around tank should be firm enough to hold tank in place but soft enough to absorb the majority of vibration ; so reducing fuel foaming . Some fuels include an anti foaming agent . If you cant find out weather or not your fuel contains this then A small spray/few drops  of silicone furniture  polish or silicone dash boards treatment added to your fuel will stop foaming . You may be unlucky and have an unbalanced engine . I have seen these crop up over the years and theres not a lot you can do about that . Hope this pints you to the fault .   Regards   E.D.

Hello Dave .  Just a note of warning .My Gemini 120 MK1 twin was sechond hand and had been stored for some time  after being run on Castor fuel. The seller assured me it had been oiled up etc before storage . The castor had set like Varnish in the big end oilways and caused them to fail after a couple of minutes running.  Fortunately it didnt damage the crank shaft . The really annoying thing is that Conrods are unavailable for these engines and are totally different from the MK2 engine .t Mr Haytree helped me to rebuild with a couple of  good seconhand rods taken from a breaker he had. If your engine has been run recently then it will probably be ok . If it feel s stiff and gummed up then either strip and check it or fill the case with solvent that will disolve any castor varnish   and oil thoroughly before running . The oil ways are two tiny holes through the walls of the big end and block easily .  I imagine that parts for these engines ( apart from things like NV assemblies common to other models )are now extremely rare . Good luck with it . E.D. ps . conrods made good key ring fob

Hello Mr Tall . I pretty sureits just a collet type prop driver but if you want to confirm then Give weston UK a ring on 01795-522020 . They are the UK distributor now and will be able to give you any info .   E.D

Hi all . I am wondering if any other readers have had a similar experience with any CRRC pro petrol engines . I have had a CRRC 45cc for some years now . It was bought new at Watford swapmeet and  has always performed very well until recently when after a long flight it refused to start for another sortie. On closer examination the crank shaft had developed a lot of end float . I stripped the engine down and found that the bearings had started to float and rotate  in the crank case . This produced  aluminium patricles that found their way to the piston ring and decided to pick up on the chrome cylinder walls . Bits of chrome then found their way into bearings etc . I have a couple of these engines and this ,being an early model is the only one to show sloppy fits from new. After a thorough strip and clean ( you'd be amazed at the ammount of metalic particles that wash out of an engine) I decide to rebuild it . New bearings from a local bearing supplier where fitted using  Loctite bearing fit . This should hold them firmly in situ and a  steel shim was made up to reduce the end float on the crank to an accepltable level . Falcon Aviation supplied a new cylinder and piston rings (priced very reasonably and delivered very quickly ) .Once assembled it now runs superbly and is much quiter mecanically . I have run it for about half an hour so far on a 25- 1 mix fuel to get  running in started and it feels very smooth compared to it feel from new . I know these are budget chinese engines but beware of the early examples as the machining was obviously very hit and miss .    E.DEdited By Engine Doctor on 19/06/2010 11:23:00

Hello Paul . sounds like your add on silencer was causing too much back pressure .  You haven't removed the return spring on the butterfly arm have you? I know a lot of flyers that unhook it as they think its too strong for the servo. If you do this WILL allow the butterfly bearings  to chatter and wear quickly ,this allows air to get through and only remedy is a new carb. I run a DL 50 ( forrunner of DLE55) and its quite happy on 40 to 1 mix and will shortly be going to 50 to 1 . Its had a few hour running now. If you find that the standard muffler is too noisy as I did on the 50cc  then give me a e-mail and I'll show how I modded mine with vrtually no loss in performance to reduce the noise. Regards

Hello David . Iv'e been using Southern Modelcraft fuel for years and as said earlier it changes colour from a dark pink to a dark brown ,as said , just like tea . Apparently it a reaction to UV rays. It doesnt harm it at all and will be fine to use . This colour change happens with various fuels that use Synthetic oil.Pro-synth used to start off a light blue and quickly went a almost black if left in the sun . I think a new dye is used now that is resistant to clou change  Castor will stay a straw colour . Use and enjoy .   E.D.