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BCMIEV20RC - BCM 5619

BCMIEV20RC - BCM 5619

75.58

BCM Inverted muffler for the Evolution 20cc petrol engine with a cut away for round cowl. Dimensions: A=90mm D=64mm L=115mm W=30mm. The exhaust flange is 12mm thick.
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BCMWADL55 - BCM 10514

BCMWADL55 - BCM 10514

144.00

Wrap Around Inverted muffler for DLE55 with extra noise reduction. Dimensions A=3mm, B=76mm, C=25mm D=50mm. The exhaust flange is 10mm thick.
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BCMIDL35 - BCM 10506

BCMIDL35 - BCM 10506

78.60

BCM Inverted muffler for the DL35 rear exhaust. Dimensions A=76mm B=51 C=115mm. The exhaust flange is 10mm thick.
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BCMIOSGT33 - BCM 4034

BCMIOSGT33 - BCM 4034

75.58

BCM Inverted muffler for the OS GT33cc petrol engine. Dimensions A=76mm D=82mm L=102mm W=32mm. The exhaust flange is 32mm thick.
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Zenoah G800BPU 80cc Flat Twin Aero Engine

Zenoah G800BPU  80cc Flat Twin Aero Engine

599.00

!!<Specification:

Cylinder displacement: 79.9 cm / 4.88 cu.inch
Cylinder bore: 40.5 mm / 1.59 inch
Cylinder stroke: 31 mm / 1.22 inch
Power output: 4.34 kW
Carburettor: ...
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Zenoah G62PU 62cc Aero Engine

Zenoah G62PU  62cc Aero Engine

310.00

!!<Specification:

Cylinder displacement: 62 cm / 3.78 cu.inch
Cylinder bore: 47.5 mm / 1.87 inch
Cylinder stroke: 35 mm / 1.38 inch
Power output: 3.15 kW
Carburettor: ...
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G450PU 45cc Aero Engine

G450PU 45cc Aero Engine

299.00

45cc Side exhaust petrol Engine with Zenoah Magneto ignition as standard !!<Specification:

Cylinder displacement: 45 cm / 2.75 cu.inch
Cylinder bore: 43 mm / ...
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Zenoah G380PU 38cc Rear Exhaust Aero Engine

Zenoah G380PU  38cc Rear Exhaust Aero Engine

238.00

38cc rear exhaust engine with magneto ignition as standard !!<Specification:

Cylinder displacement: 37.4 cm / 2.28 cu.inch
Cylinder bore: 38 ...
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Zenoah G260PU 26cc Aero engine

Zenoah G260PU  26cc Aero engine

244.00

!!<Specification:

Cylinder displacement: 25.4 cm / 1.55 cu.inch
Cylinder bore: 34 mm / 1.34 inch
Cylinder stroke: 28 mm / 1.1 inch
Power output: 1.62 ...
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1/8 Robart "T" couplers (pack of four)

6.50

For joining fuel tube good for glow or petrol. !!<Glow OnlyPetrol Only Suitable for Glow fuel ...
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3/32 Robart "T" couplers (pack of four)

3/32 Robart

6.50

For joining fuel tube good for glow or petrol. !!<Glow OnlyPetrol Only Suitable ...
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Multi cylinder glow start

Multi cylinder glow start

156.00

The perfect solution for starting your multi cylinder glow engine without the need for an on-board glow system or a massive battery pack. It is powered by ...
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Three Cylinder Glow Driver

Three Cylinder Glow Driver

60.00

The compact unit operates 3 glow plugs independently using a single cell LiPo or 3 cell NimH battery. The switch-on point is programmable and the unit will automatically turn the plug ...
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Electric smoke pump

Electric smoke pump

46.50

A powerful self priming pump that plugs straight into a switched channel on your receiver. No need for an external power supply. The diaphragm pump works ...
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X-OS25830010 OS Engine Crankshaft Bearing(R)50H/55AX/55HZ

22.99

OS Engine Crankshaft Bearing(R)50H/55AX/55HZ
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RCM&E Jan 10

Just Engines Online | Ignition Systems | Magazine Articles and Reviews of our Ignition Systems |  RCM&E Jan 10

More Spark by Brian Winch

In the December issue we began our look at converting glow engines to spark ignition the next stop in our investigation being to understand the need for timing adjustment.

Now during my younger days, when I was hopping on and off of every type of motorcycle I could obtain by buying, exchanging or borrowing, I somehow ended up with a large, old Harley Davidson. A great old bone-shaker that ran quite well, but you had to be right on the button when starting it. The kick-start had a bicycle pedal instead of a bar for pushing down with your foot, and there was a lever on the handlebars to control the ignition - you could advance or retard it as required; for starting it had to be in the full retard position otherwise that kick-start would bounce right back like a rabbit trap and imprint a message into your shin. The message was -'you bonehead, you forgot to retard the ignition'. Well, I gotta tell you, that pedal really hit hard and I still bear the scar. I was a fast learner, though, as it took only one shin bashing to remind me - always - to retard the ignition lever and hold it retarded whilst kick-starting the beast.

A couple of my early cars had the same type of lever on the steering column, and you had to remember to set it in the retard position whilst crank-starting the car (by hand). The spark lever on spark ignition model engines of the time was adjusted in similar manner, or you'd cop a goodly whack on the fingers when the prop flicked back rapidly due to the ignition being too far advanced for starting. Experience taught you to fine tune the ignition to suit the propeller load. When using a very large propeller you'd trim the ignition towards the retarded position, and gauge the result by ear - you could hear the engine running smoothly when the adjustment was correct.

Back to the cars and motorcycles. The cars of that era weren't overly generous with horsepower, and this coupled with the oft-horrendous roads and steep hills meant that you needed to maintain control over the ignition, using full advance for smooth, low-load touring, bringing the lever back to the retarded position when a steep hill was encountered (particularly when you had the entire family aboard). It was a boon when the automatic advance system was incorporated in car ignition. In one respect the changes in modern vehicles are very similar, except that all the changing and movement is now done by jelly beans (jelly beans - my overall description of the small and often coloured components on a circuit board of an electronic device).

As mentioned above, tuning early spark ignition model engines required attention to the timing lever - retarded to start, then advanced to the premium setting according to the propeller load. Well, the good news is that we can - almost - dispense with this when using modern CDI units, as they take care of that need. Generally speaking, the range of ignition control is well within the range of propeller sizes you'd normally use on the engine, however, even this can be varied, and this is why I said 'almost' in the previous sentence.

A little information on a (sadly no longer manufactured) all-British engine - the Merco (this is related to our subject matter, so bear with me!) Merco produced quite a range of engines with several innovations that were quite good and, probably, a little ahead of the times. Such things as a three-needle carburettor, two glow plugs and, even before it became essentially fashionable, effective exhaust mufflers. The engines were available in all configurations: diesel, glow and spark ignition, and the 10cc (.60) version of the latter had a feature that would certainly appeal to some modellers these days - a very small electronic ignition system. The recommended propeller for initial running was a 13 x 6", which is at the large end of the range for 10cc if it was glow ignition, but not a problem for this petrol engine due to the automatic advance/retard ignition control. Just behind the carburettor was a small micro switch and, on the throttle rotor, a plastic cam plate. If you wanted to run 16" or larger propellers (remember, this engine was only 10cc) you adjusted the cam plate so that it closed the micro switch, and this action changed the timing of the engine so the ignition range was retarded to cope with the increased load and to prevent the engine overheating and / or pre-igniting (pinging). So here we are with a 10cc engine capable of swinging 16" props and larger - 20 to 25cc engine props - just by simply retarding the ignition timing. For checking purposes I used an 18 x 4" narrow prop on the engine, and it ran quite well without overheating or any signs of distress.

Now for my aforementioned 'almost' - this will be to our advantage. When we get to setting up the sensor for the conversion, I'll show you a method or two to allow you to have this broad ignition control if you want to use larger-than-normal propellers on your engine.

Just Engines Online | Ignition Systems | Magazine Articles and Reviews of our Ignition Systems |  RCM&E Jan 10