Adrian Smith 1

My routine Tom is to have four flights per session with around 6-7 minutes flying time largely because I find with me that any longer and my attention wanders doing serious aeros! A mistake I made manys years ago and not to be repeated. For my 2700 mah Nimh after a session such as this, on a recharge it will take 300-400 mah using a fast charge with a readout of input. I also have a voltage checker on board in a prominant position in the cockpit area for safety given that Nimhs have history of tailing off if you are not careful. I recycle twice a year and at the first sign of any drop in capacity the battery gets binned and a new one put in. It's a routine that has stood me well as thus far I have not lost a plane through power failure - other ways yes but not a dodgy cell or two! Hope that helps.Edited By Adrian Smith 1 on 10/01/2012 20:06:36

You should have oodles of power to spare with that engine. I am sure you'll enjoy the plane - it really is a great performer.

OOps forgot.... all servos are futaba with working sufaces 20KG/cm at 6v using the s9152. the throttle is on a standard servo though.

Hi Tom, My set up is quite straight forward in that power is provided by an OS Max BGX-1 Ring engine using a 20 x 8 APC prop (producing 8k revs comfortably without straining . Despite being 36cc it provides 4.1ps of grunt which does all that is required of this 50cc model + it's quieter than petrol at 81dB. Electrics & RX are driven by 2700mAh 6 volt battery. That's it really I just like to keep it simple.

Like Steve I have Goldwing aircraft but mine is the Sbach 342 30cc and I also have Slipstream 50cc Sbach 342. They are both fantastic models and fliers, the best I have had! Incidentally, Model Maniacs has an offer on 50cc Slipstream kits of £50 off.

Yes John my impression is they are a bit brittle although my ham-fistedness didn't help I am sure. For the 91FX, 17 quid for a new ring I think I need to be ultra careful when I go back to the job. Anyway at least I know more about the pitfalls. I also replaced the bearings in the 91FX and I must say that was the easy part of the job.

Thanks Del that's an instructive picture. I will go away and investigate.

Hmmm... that's interesting I never even thought to look for something like that. When I go down the work shop tomorrow I will have a look at that. Sounds like I may have made a basic error there.

I am sorting through some old engines and doing a major refurb. I have come across an OS 91FX where in the dim and distant past I tried to replace the ring on the piston. I vaguely remember breaking one ring trying to put it on and when I did do it without snapping it, it stood too proud and the ring opening fouled the liner ports. It was a genuine OS ring part but I thought I might try again with a new piston ring. Any tips on how to do this right? Thanks.

On the off chance I wandered down to the field yesterday to see if it was flyable after becoming stir crazy due to a week without flying. Bit breezy but back to the work shop where my battered Capiche 140 powered by an OS 160FX was loaded up. That plane just loves the wind and is very difficult to stall and four flights later I was glowing with pleasure. To think I was going to transfer the gear and motor out of the tired old airframe and put into a new unmade Capiche 140 kit that had been on my shelf for the best part of a year. Well there's life in the old machine yet and I think I will hold fire on the aero-euthanasia for a while yet!

Right-ho that's great. Fortunately there is not a huge amount of carbon to remove so hopefully shouldn't be a big job.

Steve, I took your advice rather than Myron's and used a large plastic bag to remove the collets, retainer and valve spring! A good job too as those collets are pesky little items. Now comes silly question time. After decoking the valve faces I am now going to put the valve sets back to gether. Am I right in thinking that the collets (they are tapered) are put back with the taper pointing downwards? (towards the valve bottom). It's just that I can't see how they would do the job of holding the retainer with the taper upwards. I must admit when dismantling them in the bag I didn't notice which way up they were before they came flying out.

Thanks for your update Alan, I am sure it will be fun when I get round to doing it but at least I will now be a lot more confident after all the good advice. I must admit Martin that when I put the camshaft back in the engine of my OS 120 that I found using a piece of fuel tube attached to the spindle enabled me to line the item up correctly before putting the cam followers in. It's also a method I use to put back glow plugs into engines that are cowled so that the thread engages before sliding in the plug spanner to finish the job.

As usual Martin & Alan you are full of good advice and I will approach that task when I have to do it with a lot more confidence. Many thanks!

I do read the WOO, although I can't rember which issue the valve spring cotter removal would be in. Any ideas to save trawling through my mags. Mind you at least I am not like that chap reported in the news today whose 7000 boating mags fell through the ceiling on him! Could have been worse had the firemen had to cart out boxes of Naturist Monthly!

Well now I have gone through the hoop I will not think twice about doing it again. Having been given a kicking by Steve H for not asking the forum first, I thought I would test his assertion by asking a question.   On some of the bigger OS four strokes (120 included) I notice in the manual that the valve springs are held in place by a two piece split cotter and a one piece retainer. Can anyone tell me a foolproof way of dismantling them without damaging or bending these retaining items. They differ from the OS 52FS in that this has a one piece circlip type of arrangement by the looks of it which looks a bit more straight forward.   As you can see I am really trying to hone up my engineering abilities!

I decided that my two OS120 FS engines badly needed both sets of bearings changing, as they looked a bit rusty. Yes Model Fixings had them in stock so I took the plunge and they duly arrived 24 hours later. I had done this operation a few times before on two strokes although I realised four strokes have few more bits to dismantle, but how difficult can it be? I researched the method via articles in RCM&E and watched the YouTube vids on how to dismantle and reassemble an OS 52 FS. All very straightforward. The changing of the bearings was accomplished without stress and adjusting of the valves completed cold with a feeler gauge and Bob’s your uncle! Or not. I tried to start the first engine and after much fiddling about and valve readjustment – nothing. After a couple hours of this I had a tantrum and sent the engine off to John at Motorvation. He felt sure it wouldn’t take him long to solve and a payment of £20 would suffice. What had happened was I had done the job correctly, but the TIMING was incorrect. What the devil’s that as nothing was mentioned about this in any tutorials I had studied. Apparently there is a small dot on camshaft cog that should be in line with push rod tubes when the engines is at TDC. When I had assembled the camshaft in the housing I had put it in 3 teeth away from where it should be. Viola! All is now well with the first engine and looking at the second motor on my workbench I realised that wouldn’t be likely to start for the same reason! So that engine is now fit and healthy. Anyway the point I want to make is never be afraid to try something new in your maintenance routines because it’s all a learning curve and you will get there in the end!

Blimey Myron, I have fantasized a thousand times about doing what you are lucky enough to do. I agree that it should be "your" club so can have the control you need. I have searched high and low for such an opportunity in Mid-Suffolk with the sort of out of the way acreage you have at your disposal. So far I have drawn a blank, but I haven't given up yet. We face the prospect of losing our site when wind turbines could possibly be built. Sorry to sound so pleading and needy but if there is such a facility to set up a club and fly in Suffolk I would love to know!!

Thanks guys that's very helpful. I think the experiment is worth a try and it's nice to hear from folks who have used these pumps. The engine I intend using it on is an OS 120E four stroke on a CMP Leo where the tank sits on the CoG and quite a way back. The engine uses muffler pressure so I'll go that route. I did notice that there is breather nipple in the crankcase which presumably won't affect the operation of the pump.

I am thinking of using a Perry Pump (V-20) on my four stroke 120 as I have locate the fuel tank over the CG. I know these punps have a round for a while, but wondered if they are reliable and easy to set up as I don't want to buy a new pumped engine. Thank for any thoughts.

Also check out the vid on Weston's website of both the Capiche & Obsession. Both are capable of 3D etc if thats your bag. The Obsession is designed for 160 two stroke or comparable 4 stroke. Take it from me you won't need any more power for what your son wants! Both planes have adequate working surfaces to do the extreme moves, so just choose the right prop that suits your style.

Tom, I am using a stock muffler on both. On the Obsession the engine is inverted with the muffler outside while the Capiche has the engine at an angle so the muffler is pointing between the U/C legs. As far as performance goes without a pipe the Obsession does the lot as its AUW is a tad under 4kg. May be with the Capiche a tuned pipe would be necessary to "do the book" as the AUW of mine is nearer 5.35kg. That said both do standard aeros with capacity to spare and unlimited vertical performance. It's just a case of how much you want to spend on extras such a tuned pipe. Hope that's of help to you both.

Tom,   I have a 160 FX in my Weston Capiche 140 and Weston Obsession and it has plenty of power to do what you require for a plane of Seagull Edge's size. A lot will depend depend on your preferred engine- prop combo. I have used and APC 17x10N on both my machines although the Obession is better suited and goes like a rocket!! Best of luck with what you choose. adrian

I know tell me about it Paul. Thats really why I was trying to get second hand spares or an old bust engine.   Given that a new 120 pumper costs in excess of 300 quid I don't want to go that route just yet. I have bought cheaper non- OS engines in the past and really they were not up to the job. Therefore, one goes back to buying OS thereby spending even more money so it's a false economy.   I suppose it's a fact of life that spares are made either expensive or hard to get thereby churning the buy from new market and keeping the manufacturer happy.  

I have to say that I have had selling success on both the RCME website and in the mag which seems to publish the ad in the next magazine edition after web posing. Some potential buyers have expressed annoyance that quite often the item is already sold by the time the mag is published even when they phone me on the issue's first day out/delivery.   Additionally though, I have had more time wasters via the website as they are plugged into ebay and want to see if you will sell them stuff for next to nothing. However, both method of selling on RCME have their virtues.