Rickskid

Hi everyone,

I purchased a Quickstart Wasp 0.49 Glo engine way back in 1976 to go into a Keil Kraft Cessna 150 Free Flight model that I never finished building. I was 17 at the time and remember running it up in my bedroom and the cloud of oily mist smelling of oil and ether that appeared.

Cut forward 42 years and I have got back into Aeromodelling again with electric RC models but was enchanted by the "Chuck and duck" at the NATs at Barkston last August. I would like to build a 40 inch span Junior Junior and make it FF assist with some lightweight 2 channel RC gear in it with a small engine on the front. I have a 1.5CC DC Sabre diesel engine (I think as it has a red cylinder head) that I got running last week and ruined the inside of my shed with oil residue splattered every where. So I thought I'd give the 0.49 glo a try to see if it is any cleaner.

We found a large bottle of turquoise coloured Nitro Fuel in an old cupboard in the Club house the other day and I thought I'd give it a go with that stuff. After fixing the engine on a board and then into a vice I connected a small fuel tank, bought a new Ripmax glo starter and tried to get it going. It pops and kicks and runs for about 2 seconds then stops (I've lost that spring thing on the front of the engine so rely on finger flicking). It absolutely refuses to run.

Am I using the wrong fuel? The bottle is years old and doesn't smell of ether like I remember.

I bought a new glo plug but the original one "fizzes" fine when connected to the battery as it seems to be glowing okay.

Can anyone help please. If I need different fuel, then what do I buy and where on the web can I buy a small can of it as I don't need gallons of the stuff.

Hoping someone can help, thanks in anticipation.

Ian

mgnostic

Hmm....Ether is usually associated with diesel engines not glow. Just based on what you have written there are a couple of potential problems. First is the unknown fuel. .049s and other "half a" engines like to have a relatively high nitro content. I've not run a Wasp but my Cox and OK Cub engines seem to like fuel with 20% nitromethane content. the Wasp may not need that much nitro but if the fuel has set around in the back of the shed for a couple of years the nitro in the fuel may have gone flat or the fuel may have absorbed a certain amount of water. That fuel might still run in a larger engine but could be giving trouble in a small motor such as the Wasp. Your description sounds like the engine is starting on the prime and dying as soon as the initial bit of fuel is burned off. Small engines have small fuel passages and it is easy for then to get clogged with old dried up castor oil. so make sure that the fuel passages are clear. Two turns on a half a needle is not necessarily the same as two turns on a larger motor. I have found that I have to open the needle valve a little father than that I would have expected from my experience with larger motors. You don't specify the size of the fuel tank but this can also be an issue. Small engines don't like big fuel tanks since they don't have a very strong fuel draw. If you think back to the models at Barkston you will notice they all have very small tanks. Since the engine is starting long enough to burn off the prime the glow plug is at least functional but when buying plugs get the hottest plug you can find. Since you are referencing Barkston I presume that you are in the U.K. I'm not familiar with your local vendors but I would suggest looking to companies that support control line or free flight as 1/2 A engines are still popular in the circles. You may be able to buy fuel in a half liter or smaller can. This will last a long time when flying .049s. Be careful with the electric starter as it is easy to cause a lot of wear to the crankcase snout. Once you get round the tricks of running small engines they are a lot of fun. I'm located in Texas but I have seen videos of the "Chuck and Duck". It looks like massive fun.

ffkiwi

A couple of points to ponder-other than those already raised by mgnostic (and I absolutely agree re his comments on fuel-quite apart from the age, the nitro content-if any-is likely to be too low for the Wasp)-as he indicated something of the order of 15-20% nitro is ideal-and I'm pretty sure the published engine test (July 1971 Aeromodeller) was carried out on 15%-and the Wasp having a ball and socket joint little end, needs the benefit of decent oil-preferably castor-and plenty of it-at least 20% total lube (need not ALL be castor though) in the fuel. If you have run it in the past then there is a very good chance the spraybar is clogged or partially clogged with fuel residue from 42 years ago! This might be in the barrel of the spaybar-or worse still-clogging the jet hole-so check the spraybar is clear by using a pipe cleaner or similar-and a pin to check the jet hole(s)-you'll need to tighten up securely again-and ensure the spraybar jet hole-if only one-is pointing downwards in the venturi-or if it is a two hole spraybar-with the holes at 180 degrees-the holes are aligned horizontally. The needle itself should be OK, and 3-3-1/2 turns open should be adequate for starting-the spraybar thread is 5BA so it is not a fine thread like the Coxes.

Two other areas of potential concern-the plug and the head joint-plugs age and can get contaminated-and whilst still glowing OK may not work efficiently with time-or even at all-despite being visually OK when tested on a battery. Secondly the head gasket in the Wasp is a fibre job-which is easily damaged and may tear when trying to change the plug and the whole head unscrews rather than the glowplug-the usual response is to really tighten the head up-which can often squash the gasket too much. Wasp gaskets are virtually unobtainable except by sheer chance-after all the engine has been out of production since the early 1980s. A Cox glowhead gasket-or a couple of them-will fit in the gasket location in the head underside and make an acceptable subsitute-if the original gasket is there but compressed I'd leave it in place and drop a Cox one on top then tighten the head up gently-that way you don't get the gasket welding itself with time to both the top of the cylinder and the underside of the head. The Wasp cylinder is virtually parallel all the way to the top-there is no top flange- only a narrow ~1/16" rim at the top of the cylinder-with a matching flat area inside the head-for the gasket to seat on. Not a great idea, structurally!

That about covers the likely problem areas-I presume the backplate is tight-a loose backplate will leak primary compression-and do your starting attempts no good at all! Fit a suitable tank-level with the spraybar-and as close to the engine as you can reasonably mount it-I assume from your comments initially that your Wasp doesn't have either the integral or radial tank options that you could buy it with-and just like the gaskets-these are very very hard to come by these days! Try 3 turns open on the needle and see if it will draw fuel. If it doesn't then either you have a loose backplate or you still have a blockage. If it will draw fuel through the line-you are using a clear fuel line I hope!......but has trouble keeping it up to the end of the spraybar, try blocking half the intake with a sliver of balsa wedged in-this was an old trick often used with DC Merlins which sometimes suffered from a lack of 'suck'. If it still persists in not running then I start by replacing the plug-Merlin glowplugs in their very extensive plug range-offer plugs specifically tailored for small engines such as the Wasp-check their 2001-2, 2002-2 and 2004-2 types. [In desperation fit an OS #8 which seems to work just about any engine!] See: www.merlinglowplugs.com for the full Merlin range.

I have to confess that my own reasonable extensive experience with these engines-I have about 5 or 6 accumulated over the years-some Wasps some the Frog Venom 'badge engineered' version-leads me to comment that they don't hand start by flicking that well-and the spring starter setup is a good idea (whereas its benefit on the DC diesels is questionable...) Since you have lost yours, all I can suggest is a) perseverance or b) fit a Cox spinner (you'll need a longer prop screw-which is 6BA thread-the Cox prop screw won't fit, being US 5-40-and if you can get it-a round head rather than a cheese head looks better and blends in the Cox spinner shape better-a quick check on a Cox Td 049 screw reveals it is 1" threaded length- so you want a 1" 6BA machine screw if you take this option-then you can use a suitable sized electric starter-there are some nice 1/2A ones around-plus the Sullivan Hornet-which is good up to about 2.5cc, so a little more useful than a purely 1/2A one [I have both types-as I have a lot of very small sub 1/2A glows, and the genuine 1/2A starters-the Miller in particular-have inserts that you can use right down to 010 size.

Good luck with the Wasp-once you sort it, you'll find it about on par with a Cox Babe Bee-no ball of fire power wise-but lacking some of the Babe Bees annoying habits-especially the main one of backwards starts!

ChrisM
'ffkiwi'

PS Just like a Babe Bee-your props for the Wasp should be between 5x3 and 6x4-nothing bigger.......and there's no point going smaller than 5x3!
PPS Model Technics is a UK firm specialising in fuel.....and glowplugs....so may be worth calling them to see what plug they recommend for the Wasp (they have an extensive range-though not quite as many as Merlin!)-and they can certainly supply you with fuel-their GN-16 or GN 25 mix is available in half litre packs [they do a vast range of fuel mixes BTW-most of which are NOT suitable for the Wasp-but the two I suggest are castor based and have adequate levels of lubricant in the mix.] See www.modeltechnics.com The downloadable UK pricelist is in the left hand side menu on the homepage