OS 25 FSR- Equivalent

[Martin McIntosh]

I had an OS 25 `Fizzer` (could have been a 19) a long time ago and was very disappointed with the power. No match for a 25FX of which I have two. Don`t know if Ripmax still do the free replacement for life on the liner due to the vulnerable coating. I also have a couple of West 36`s which are very powerful and good all round, so if these are anything to go by then their 25 should be great. The 36`s will handle an 11x6 no problem.

[Braddock, VC]

I have an OS 25 F which is the ABC version of the 25 fsr, I've only run it less than an hour, first with the original silencer on and then with a TT 42 GP silencer fitted which really quietened it down and also let it rev better (the manifold bolt holes have the same pcd). It flew a seagull jumper as if it were made for it but I replaced it with another engine and stored it.

I was going to fit it in a downsized wot4 but it's not going to happen. If you want to buy it, send me a pm and I'm sure we can reach an amicable arrangement.

[Nigel R]

The irvine 36 was a lovely motor.

39 is just as good and some extra capacity. And more importantly still available for frankly excellent price given the quality of the motor.

[TartanMac]

I should probably mention there were 2 versions of the Irvine 36 the abc had 2 Phillips screws holding the carb in that is the one you want. Not the ringed version that had a pinch bolt holding the carb in. The ringed one has much less power. I only mention as I see some ringed 36 engines are available and don't want people to buy that by mistake.

[Paul Marsh]

I have an Enya 25SS and 30. Very powerful motors. Thing is , go to the up coming swapmeets and there are usually loads of .25 size engines going for nothing. Take your pick..

[Braddock, VC]

I wouldn't bother buying Irvines, spares have dried up especially carb spares so unless you buy the complete carb you're up the creek.

I've just relegated 2 x 36 and 1 thirty nine to the spares bin for want of a couple of quid's worth of spares.

Fantastic engines though, must have been too much competition for OS and so they pulled the plug on them.

[Nigel R]

Indeed they were, I would guess bought for OS purely to test certain overseas production capability before being canned.

[Martin Harris - Moderator]

Posted by Percy Verance on 14/01/2019 18:02:43:

MDS may well come back ED, but who will buy one? Certainly not anyone who got caught last time...... Ripmax will need to re-brand them in the hope of finding new unsuspecting fools buyers........and in our game - perhaps more than most - mud sticks.

Wasn't that where the short lived RMX engines came from? Funnily enough, I have 2 MDS engines which perform beautifully. One, a 58 was (figuratively speaking) thrown at me in preference to the bin as the owner coudn't get any joy from it - half an hour's tuning and running saw it settle down and deliver great power reliably and I still use it regularly well over a decade later. The other (38) came on a second hand funfly and it now comes out on my float equipped Limbo Dancer whenever it snows.

I think the main problem was they were aimed at beginners and could be a bit finicky until properly run in.

[John Duncker]

The popular Club 2000 pylon racers use 25s as they are going electric there will be engines going spare.

two possible contacts are Michael Toyer on: 01933 675378

and RadioActive 01905 776073

[Tosh McCaber]

Thanks for all the replies so far- it's developed into an interesting discussion!

Jim

[Braddock, VC]

MDS got a well deserved poor reputation that was basically down to the importers not emphasising the fuel to use.

They shared one trait with MOKI 2 stroke glow engines and that was they thrived on straight castor fuel, no nitro just fai pylon fuel.

They also revved much higher than their contemporaries iirc. I had a few, a well used 48 that I had to sell as I found I became allergic to castor fumes and a 218 which was a monster.

I got the same as what I gave for them, £35 for the 48 and £?? for the 218 which was big bucks at the turn of the century.

Both were bought by fellow club members who were impressed by their performance.

Nitro was as common as rocking horse poo in the then soviet bloc and it and their synthetic lub oils were non existent there (to the average modeller) when the engines were developed.

Found out about the moki quite by accident, a 135 wasn't performing, overheating and deadsticking on 5% model technics (iirc) I gave the owner the 1/2 gallon of castor straight I had in the back of my car and he never looked back, gave me a new os F plug as a swap so I did alright out of that, too. That engine came from the soviet bloc, too.

Edited By Braddock, VC on 30/01/2019 13:01:40

[Martin McIntosh]

Way off thread now, but when I restarted the hobby in 1998 after an enforced lay off due to business needs I started to get a few things together like a computer radio, hairy aerobat kit and a motor which the model press was raving about. Yeah, you guessed it, an MDS 48.

The throttle would stick at full because the barrel slot had been milled out into the shape of a letter P. A needle file sorted it. I could get the motor to run very well using 10% nitro and a medium heat plug. It had a very slow and reliable idle which astounded my new clubmates. Gave it away in the end but the new owner could not even get it to start.

[John Duncker]

I had very good experiences with MDS engines.

I had 3 38s one in a 3D model and two in helis run them on 5% run them in and set the slow running jet CAREFULLY making tiny adjustements as it very sensitive.

A 148 iand a 218 both in 3 D models. I found them to be powerful reliable and throttled well.

Once you got the needle setting right I left it alone, it was flick and fly. I got into trouble from the club instructor safety officer who said I set a bad example by not doing a nose up test.

2 clicks richer in winter and you were good to go

Even the much maligned 40 can be a good engine but the early ones needed some silicone sealant under the carb and again some running in.and careful slow running ajustement.

There were some lemons I came across a couple of 78s that I could not get to run well and I have no idea why.

But expect them to run streight out of the box on high nitro fuel and you will be rewarded with a Mostly Dead Stick Door Stop.

Will MDS or any of the other IC engine manufacturers be resurrected I think it unlikely as the model business has gone electric.

Edited By John Duncker on 30/01/2019 14:38:46