Roger Dyke

Thanks for that, I'll give it a try. My question really was, which way around is the default supplied position as the previous owner has probably moved it.

Hi all, I have just purchased a second hand Irvine 46 mk3 (red one). It's silencer is stamped "1E". Inside the silencer is a cone baffle with a hole at the pointed end. The cone is trapped between the two silencer halves. In parting the two halves, I found the cone with it's narrow end pointing towards the engine. Is this correct, as I was sort of thinking that the pointed end of the cone should be facing the outlet to the rear?

I have just removed an OS 40FP from a model (unscheduled arrival.....). I remember purchasing it new back in the 90's. 100% reliable engine. Best engine ever.

Thanks Manish. Taken on board and noted.

My thanks to you all for your wonderful and comprehensive replies. You have certainly give me a lot to go at when I'm next down at the field.

John and GG: Thanks for your input. Martin: Yes, it does have flight modes. I hadn't really looked at that. I don't really want to make it complicated. I like to keep it simple being old school. Nick: I missed that. I'll have another look. Thanks for that. Chris: Thanks for your thoughts.

I don't think my Spektrum DX6 G3 has got the servo slow facility. Shame as that could have been useful. I think that I am having to re-think my idling and throttling as what I am after is probably not possible (ideal world).

I do run 5% nitro (newish fuel) and aircraft balance is good. Yes, a minute is a long time for a glow engine isn't it. I hadn't really considered the cooling down making that much difference but you may be right. With the slow idle I'm probably trying to over-egg the pudding, as they say. Thanks for that.

Thank all for the info. I usually aim for about a minute or so idling time, but no matter how I fine tune the slow needle, I always have to be careful how fast I increase the throttle for the revs to pick up after that time. Otherwises it's touch and go whether they suddenly quit. From what you say, It sounds quite normal. By the way, the two engines in question are a Super Custom 61A with a new carb and a Irvine 61 Mk2 (red one). Both are in very good condition with good compression. The props are 13x6 APC.

Hi All, Although reasonably conversant with 2 stroke engines, I am always at a bit of a loss as to what RPM to set the slow running to. Too quick tends to carry the aircraft down the runway when landing and too slow givies me probiems with throttle pickup when when abruptly opening the throttle (for a possible go-around). I usually aim for about 2300 RPM but feel that probably it's a bit slow and unpredictable on the pickup. Is there a favoured RPM?

Gary: Thanks for the conversion info. I'll bear that in mind if I start looking for another engine.

Gary: You've answered a question there. I was wondering that if I chose to install another engine, what the chances would be of moving the rear needle valve to the front carb position. Thanks for that.

Nigel: I think that I'll leave the low mixture needle the way it is for now. My thanks to you all for all that the useful information. I purchased the engine new in about 1995 and it has given me good service. I can't remember it being difficult to control back then. In about 2002 I gave up model flying to attain my Private Pilots Licence. I continued flying the bigger planes until the end of 2018 when I reverted back to model flying. That's when I resurrected my old models which had been hanging up for years. I suppose over all that time the "O" rings etc., in the carbs had been hardening, pipes clogging and all sorts. Anyway, they all had a full re-furb with new pipes, tanks and electrics etc., but not "O" rings. I appreciate that the MK1 version is probably the worst of the 3 but was always a great performer. I have just installed a brand new carb on the engine (yesterday) and it has transformed it beyond words as to what it's been like since coming back into the hobby. I think that I am okay now. It's not perfect (it never was) but is as good as it's ever going to be and I think that I am now reasonably happy with it.

Jon: Yes I have been nurturing the low mixture needle in a bit at a time exactly as you said and think I have now got it to it's optimum point. I think I am now reasonable happy with it. 14x6 eh! I might give that some thought. John: I already have an APC prop fitted. Simon: Yes, I think I am now in the right ball park. Nigel: If I was a younger man with better eyesight, I might have considered doing that. At my age though I think I'll pass on that one. Thanks for the suggestion.

Caveman: Almost the same but not quite. The cylinder case is not quite the same shape and the pinch bolt for the carb is on the front on mine whereas yours is at the rear (see photo). It pulls really well and is really powerful. It's peak RPM is 10,200 rpm on an APC 13x6 prop. and idles nicely now at about 2600 rpm. From a long tickover it is very slightly hesitant in the throttle transition (but no coughing and spluttering) if you are too abrupt, but the transition through the rest of the range now is really good.

Update: I have removed the engine from the plane and set it up on a bench stand. I have also received through the post, a brand new carb which is an ASP but is identcal (how lucky was that...). On the stand is a 6oz fuel tank with it's centre approx 1/4" below the carb spraybar. I initially set the carb up close to it's settings before installation. I've also installed a new ENYA 3 glow plug. The results are as follows:- The engine started first flick which was promising and ran it on about 3/4 throttle for about a minute to get warm. The high needle was about 1/4 turn adrift from optimum which was fine. The low needle was quite rich and spluttery so after leaning the low needle it settled down. With lots of time and patience I persevered for a good transition. Tickover is good at about 2600rpm for several minutes. The transition is still hesitant but not coughy and spluttery. If I move the throttle control from tickover to max over about 3 - 4 seconds, it picks up smoothly and fine, but if I was to just snatch it forward in about 2 seconds min to max then it's like it takes a big gulp of air and would die. I have done the "pinch test" and all sorts but now seems to be as good as I can get it. The new carb seems to be working far better than the previous carb (maybe because of the new "O" rings etc.. I was wondering, would the prop size be affecting things. I am using an APC 13x6 to keep the revs down to about 10k (because of noise). Just a thought.

Oops... Forget the above question. It is obvious it was the 15% oil. sorry about that.

I believe that there is a low oil version of the Laser 5 and also a 15% oil. Which Laser 5 were you referring to?

Have fuels moved on at all in recent times. What would be a good reliable glow fuel for general sport flying at the local club? I have been using MT Laser 5 until now but was thinking of trying Optimix 5%.

Thank you for the info regarding the fuel.

It's certainly a consideration. I have a number of other things to try first so will see how I get on with those before I try anything else.

Hi ED: I don't think it would be possible to fly with an on-board glow battery permanently fitted as there is no extra room for anything. I do have a brand new EYNA 3 purchased from a good source a short while ago which I am about to change. The fuel I have been using is Model Technics Laser 5 which is now running out and doesn't seem to be available for delivery from my usual supplier any more. Instead I am thinking of purchasing 5L of Optimix 5% to give that a try. Tank dimension height is about 2" with the centreline about 1/4" below the carb needle. I have managed to secure a brand new carb (old stock) (not arraived yet), but am aware that it might be just as bad as the one I'm using, but probably worth a go. I'm very happy with it's performance in the air. It's just the unpredictable throttle transition when the tank is starting to get low. If I have to live with it I will, rather than hack the plane about for a "possible" improvement.

I Have a new ENYA 3. I'll include replacing the glowplug on my trials next time out.

It's probably about 3 years old. I'm just coming to the last so am in the process of ordering some more.

Fuel used is Model Technics Laser 5.