Paul Jefferies Posted October 1, 2014 Share Posted October 1, 2014 Ebay can be a great source of "classic" engines and (amongst other things) I have accumulated a number of old Mercos for no better reason than I just like 'em . I tend to go for the "bargains" many of which look pretty ropey and well cooked but no matter how grotty they look on the outside, most of them have been almost pristine and showing very little signs of use on the inside with little more than slight discolouration on the piston. Perhaps I have just been lucky..... I now have four "nearly new" Merco 61s and they are all different in detail, mostly in the finning and cylinder head, as well as the obvious twin plug version. Most, if not all, of the parts seem to be interchangeable. I have found an interesting website in which Bill Morley (One of the co-founders of Merco) gives fascinating background to the company but nowhere can I find any details of the different Marks, ie., what is the difference between a Mk1 and a Mk2/3/4....... or was it just a case of gradual evolution? Can anybody throw any light on this? Paul Quote Link to comment Share on other sites More sharing options...
GONZO Posted October 1, 2014 Share Posted October 1, 2014 This site has quite a lot of general info/tests on many glow and diesel engines **LINK** Eleven entries for Merco engines of various capacity. HTH Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 1, 2014 Share Posted October 1, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 1, 2014 Share Posted October 1, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 1, 2014 Share Posted October 1, 2014 Posted by Percy Verance on 01/10/2014 20:51:33: The .29 and .35 were never held in particularly high regard by too many flyers, and consequently they're not nearly as sought after. A couple of decades back, these engines were re-launched to the market, with the .29 and .35 being marketed as a .30 and .40 respectively. Needless to say, they didn't set the market on fire. Edited By Percy Verance on 01/10/2014 20:51:58 They weren't particularly good but they had a good carburettor. I wore out a 35 while practising for my A Certificate on a Telemaster 66. I'm a slow learner! I junked the original silencer and fitted something more effective. Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 2, 2014 Share Posted October 2, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 2, 2014 Share Posted October 2, 2014 I also used a Merco 35 in the Super Sixty which flew away. Once it had been recovered I continued to use it until I entered Sam 35's Fly-In at Cocklebarrow last year. The poor old Merco struggled to move the model fast enough to permit take-off on the less-than-billiard-table-smooth patch at Cocklebarrow and received a cheer when it finally unstuck! I replaced it with an OS40 FP. Problem solved! Picture of model before the flyaway, Merco 35 up. Quote Link to comment Share on other sites More sharing options...
Paul Jefferies Posted October 2, 2014 Author Share Posted October 2, 2014 Many thanks all for your responses..... 'Love the reminiscences. Yes, the 35 was a bit of a gutless wonder but easy to start and a great "cooking engine". I'm still hoping to find another use for mine........ apart from as a fishing weight that is! Gonzo, thanks for the link. From the several reports and tests on .61s I have now been able to identify what I have. Thanks all Paul Edited By Paul Jefferies on 02/10/2014 08:04:33 Quote Link to comment Share on other sites More sharing options...
Robert Putley 1 Posted October 2, 2014 Share Posted October 2, 2014 Yes, the 61 was a great motor. Very popular in its day. My first was in a Gangster 63, purchased s/hand after my Super 60, as a first aileron trainer. Great plane, great model, great combination. On the subject of swinger large props. I purchased a mk111 twin plug to install in a Mercury IV - 8 foot span vintage model, undercamberd wings, therefore very slow. Needed much static thrust- I used a Punctillo 18x4 prop. I had to change the carb for a Kavan to get it to run satisfactorily. Massive thrust and you could almost count the blades on tickover. Ran it like that for years. A super motor. My Super 60, I fitted a McCoy 35. Super motor with bags of power. My club, instructor @ Martlesham, a disuesed wartime airfield, suggested I changed the motor for an OS 35, as the T/Over was too high for the plane to stand still. Well No OS`s available so purchases a recommended Merco 35. It was absolutely useless. It had so little power that I had to put the plane in a dive to manage a loop, and the running time was literaly about half that of the McCoy. The tick over was nice and slow!! Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 2, 2014 Share Posted October 2, 2014 Great link Gonzo....all those engine tests a real stroll down memory lane for me....I wonder what sort of dynamometer they used to use to get the torque/bhp curves for such tiny engines??? I also spotted a test on the Fuji 15 from my dim & distant past which I've never seen a reference to anywhere else & had begun to think I'd imagined.... I too have a Merco 35 in my drawer....I remember it being a real power house after my OS Max 15....it pulled my Jolly Roger around very nicely.... but the muffler should have been banned under the Trades Description Act.... Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted October 2, 2014 Share Posted October 2, 2014 35's on a Super Sixty?? I had a twin plug 61 on mine.............never had an issue with being reluctant to unstick............. Quote Link to comment Share on other sites More sharing options...
Robert Putley 1 Posted October 2, 2014 Share Posted October 2, 2014 Sure you didn`t !!! This was in 1968, the plane weigh`d four and a half pounds and was rudder only. In later years their were quite a few around like yours. Spose a Super "60" by definition should be powered by a "60" !! Good luck Dave. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted October 2, 2014 Share Posted October 2, 2014 during the 90's(last century) I had a petrol merco 61..it was quite a good engine-----must still be a few knocking around. ken Anderson...ne....1...... last century dept. Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted October 2, 2014 Share Posted October 2, 2014 There's lots of petrol engines and petrol engined models available on EBay, some of them even are............ My Super 60 was 1972, converted from rudder only to three channel, originally orange nylon covered and painted black by me.....Futaba "M" series, it wasn't light!.......it taught me take offs and landings, I wore out the club strip grass doing touch and go's, then became the club Toffee Bomber, which it did admirably, dragging a load of toffees up in an internal bay operated by full down elevator. All I ever did to the Merco 61 twin plug engine was to replace the con rod after the pressed in big end bearing fell out. The old rod is on my key ring to this day. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted October 2, 2014 Share Posted October 2, 2014 well done Dave-I gave one of my motorcycling friend's a con rod/piston out of a 40 engine...he was over the moon-had it put on a chain around his neck-bling to show off to his mate's.. ken Anderson ne.... 1 bling dept. Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted October 2, 2014 Share Posted October 2, 2014 Posted by ken anderson. on 02/10/2014 10:33:55: well done Dave-I gave one of my motorcycling friend's a con rod/piston out of a 40 engine...he was over the moon-had it put on a chain around his neck-bling to show off to his mate's.. ken Anderson ne.... 1 bling dept. Neat Ken! Maybe he'd like a con rod I still have from a Villiers 9E race tuned overbored 217cc engine from a Class IV Pirhana four speed cluthc start Kart I owned 1967 - 1972...........the big end on that highly polished knife edged rod is one soldiified lump with flattened rollers, nicely coloured by the heat..................it was doing 90 plus when the gearbox selected first...............wasn't ME, honest................. Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 2, 2014 Share Posted October 2, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
stu knowles Posted October 2, 2014 Share Posted October 2, 2014 Hi All, seeing the discussion reminded me about an engine that I have brought home to sell for a friend who has reached that age when its time to switch from planes to model railways Here it is:- As you can see it started its life as a twin plug merco 61. I presume that the brass cylinder and separate bit with a label on comprise a spark ignition system. The two wires trapped under the bright chrome punch on the right are one positive and one negative, so battery here? Immediately behind the prop driver appears to be a cam which in turn drives a set of contact breakers or points The carb is not original, the needle valve is the aluminium coloured item with large knurled knob. Between the needle valve and carb throat is another lever (black) which has a knurled section at its base. As we look at it above, the right hand side of the carb has no slow running adjuster so my guess is that the black lever probably has something to do with the slow running mixture. Looking into the exhaust port, the very light staining suggests that it has run at some point but not much. The silencer is a black steel dumpy expansion chamber of resonable size. has anyone seen anything of the sort before? Harry has no idea where it came from or how long he's had it in the drawer. Last pic for now The forward plug has the spark plug, the rearmost plug hole has a brass blanking plug. I've not had time to do anything with it as yet, I'm tempted to buy it myself and fit it to a big Popsie or similar suitable vintage. Anyone seen owt like it before? cheers stu k Edited By stu knowles on 02/10/2014 18:54:01 Quote Link to comment Share on other sites More sharing options...
FlyinBrian Posted October 2, 2014 Share Posted October 2, 2014 Shortly after starting in R/c in the late 60s early 70s I was looking for a medium sized glow motor but funds were very limited. A friend and club mate sold me an old Merco .35 for 30 shillings (£1.50) I used this for a couple of years then one day the same chap asked me if I still had the Merco .35 and offered me ............. Yes 30 shillings for it. OTOH I had a twin plug Merco .61 which was an absolute pile of poo! Quote Link to comment Share on other sites More sharing options...
Alan Gorham_ Posted October 2, 2014 Share Posted October 2, 2014 There were some 'license built' spark ignition engines based on Merco .61s made by a firm from Yorkshire in the early 1980's. It was around the time that the Vintage model movement was getting popular. That particular engine looks like a home conversion. The carb looks to be a Perry carburettor to me. Note that the ignition system you have are points (as you already know), a capacitor (the yellowish cylinder) and the coil (helpfully labelled Micro coil!). Dunham Engineering made a number of repro spark ignition engines around the early 80's era including an Orwick 64 as well as coils and perhaps spark plugs as well. The disadvantages of this system compared to more modern transistorised ignitions are the relatively high current drawn from the ignition battery, the likelihood of strong interference from the system (that gets worse as your capacitor ages) and the susceptibility of the points to the build-up of oil and oxidation on their contacts stopping a good spark from being generated. If you wanted to fly it I would suggest making up a simple transistorised ignition circuit (Google TIM-6) and definitely fit an inline switch operated by the radio between the ignition battery and ignition that will enable you to switch off the ignition in the air if the engine stops. This is because if the engine happens to stop with the points closed your coil will overheat and burn out and they are not very easy to come by these days.... Bet that's more that you wanted to know....? Quote Link to comment Share on other sites More sharing options...
brokenenglish Posted October 2, 2014 Share Posted October 2, 2014 Why do you think that the carb isn't original? The engine looks like a Merco Black Streak series to me... just converted to spark ignition, that's all. But the carb. looks like a Merco Black Streak carb... Probably a super engine. Quote Link to comment Share on other sites More sharing options...
stu knowles Posted October 2, 2014 Share Posted October 2, 2014 Hi Guys, Thanks for the comments so far, Alan, I would guess that you are spot on as far as the ignition systemn goes. If its a home conversion, then it's well done, cam etc is very neat although the poiints are a tad exposed! The carb is much bigger than a 'standard ' glow carb. I remember perry carbs on Veco engines. Again, this one is bigger although the Perrys did have a slow running adjustment by a flat disc on the same side of the carb as this one. very prone to getting blocked by the mere-est whisper of crud in the fuel as I recall. So could be a variation on a Perry, it is an ally carb body not plastic. what fuel mix ratio do we think? stu k Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 2, 2014 Share Posted October 2, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 3, 2014 Share Posted October 3, 2014 Picture of my first Senior Telemaster powered by a Merco 61. It flew it well enough but I replaced the Merco with a Thunder Tiger 91 fourstroke which I preferred. I also used the engine in an Astro Hog. Both models went in while being guided by a very old Sanwa Conquest radio. (I was always brought up never to throw anything away unless it was absolutely worn out!) I sold the radio on eBay. The new owner replaced all the black wires in the transmitter and had it checked by a qualified electronics engineer, then he flew his Junior 60 till it was just a small dot in the sky, then flew it back and landed it. He was delighted! He phoned me up to say how pleased he was! Quote Link to comment Share on other sites More sharing options...
Alan Gorham_ Posted October 3, 2014 Share Posted October 3, 2014 The points/contact breaker are exposed because (a) it's probably the easiest place to fit them onto a front induction engine and (b) you may well want to be able to retard the ignition point for easy starting. I think I'd want about 10% oil in me petrol as a staring point. I've been using Fuchs Silkolene KR2 oil in my older sparkies this year. It has a modified castor in it to allow it to mix with petrol and of course you get the benefits of the castor being slightly goopier than straight synthetic to help maintain a good piston/liner fit and to help the plain conrod bushings and crankshaft journal. The Merco may be OK on a modern synthetic but I remember that the Merco 35 and 29 had plain alloy conrods (i.e. no bronze bushings) and plain (ringless) pistons. If the 61 is the same (I can't remember - I do think it was ringed?) then I would prefer a bit of castor. I'd be interested to hear how you get on... Quote Link to comment Share on other sites More sharing options...
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