OS 46 FX

[MikeQ]

My OS 46 FX has gradually gone down hill over time and is spewing out BLACK exhaust residue. I'm lucky not to have dead sticks 50% of the time. Taking the cylinder head off I can see a lot of the plating has gone around the top.

I use Duraglow 10% and a 12x6prop on a mini pattern model. I'm usually tach the engine on the ground at 10K rpm. I'm pretty sure I don't run it lean in the air.

I had this years ago with and OS 46SF and apparently there was a fault with the liner. Anyway ... question is ... does anyone know if the OS 46 AX liner/piston is interchangeable with the OS 46FX. Or does anyone have a new ASP 46 liner/piston they'd like to part with as apparently that was a dodge.

Cheers

Mike

[Denis Watkins]

I don't know about your piston and liner Mike

But I do know that black discharge is aluminium and oil mix from rubbing

It can be just a loose vibrating silence causing the goo, so just nip up around the motor next time out to test

[MikeQ]

Hello

I'll have a look see.

Cheers

Mike

[FlyinBrian]

The FX range were the first to suffer from the peeling liner issue, my .46 suffered from this, eventually fixed under warranty. I do not recall any black goo though just a lack of compression.

[Nigel R]

I doubt the AX will interchange with the FX, the engine looks fundamentally different, 4 bolts not 6, which indicates the porting may well be in different places.

Maybe worth searching out a parts engine on ebay, or even a complete 46 to run, a used one is around £30.

[Keith Berriman]

Did I read somewhere an ASP piston and liner fits. A call to Just Engines may answer this

[Jon H]

Many OS's have suffered this issue with the cylinder plating. A friend has about 6 46fx's that have suffered.

While i have not been able to test it myself i believe the asp piston and liner from their 46 will fit the fx as the asp is a clone of that engine.

As a side note duraglo is dreadful fuel, switch to something more modern like model technics laser 5 or techpower 5. Its much cleaner and works better as well

[MikeQ]

Hello

thanks for the feedback ...If it is a common known issue do you think I might still stand a chance of getting it fixed on my FX motors ... I've actually got two with the same issue. I wouldn't care but you buy OS and pay extra for the quality and I'm sure I've never run them lean per se.

I guess its Ripmax I'd need to contact ... now that all my local model shops have gone!

Cheers

Mike

PS As far as I can see the ASP piston/liners aren't available anymore or are like hens teeth.  Either that or I'm just useless at Googling stuff.

 

 

 

 

 

 

 

Edited By MikeQ on 27/02/2019 12:22:15

[Manish Chandrayan]

ASP 46 parts will fit the OS 46 FX. Give JEN a call.

[Jon H]

The FX was discontinued donkeys years ago. There is no chance of a warranty claim at this point

[MikeQ]

Posted by Jon - Laser Engines on 27/02/2019 12:23:03:

The FX was discontinued donkeys years ago. There is no chance of a warranty claim at this point

Haha ... thought as much but 'shy bairns get nowt' as they say up here in the frigid north

I'll check out the JEN option too ... hate to waste what are otherwise good motors.

It is a bit annoying ... I know there are loads of engine torturers out there but I'm sure I'm not one of them ... and neither of these motors have been used to a great extent in reality.

Cheers

Mike

[Keith Berriman]

My goggle link says piston and liner available If not pm me as i have an asp 46 available for spares

[Nigel R]

Just Engines don't currently have any ASP stuff - until after their factory relocates - according to the JE website.

Parts engine?

f:0">https://www.ebay.co.uk/itm/rc-plane-nitro-engine-SC-46/273726999102?hash=item3fbb668a3e:g:8jkAAOSw4AJccpr9:rk:2f:0

[Alan Gorham_]

Sorry that's not right. Just Engines say they don't have any stock of ASP engines, but they have always carried a huge amount of ASP spares - my bet would be they will have a P&L set in stock.

The ASP 46 piston and liner is a well known fix for this exact problem - see various other fora and the HK website.

[extra slim]

echo Jon's point on the fuel... 'orrible'.. years ago my two strokes seemed to love it instantly, but after a few weeks/months developed lots of hot runs, and my engines started to suffer.. luckily a pal I flew with was developing new fuels (Andy at Opti) so I switched a long time ago to modern formulas.

[Nigel R]

My mistake.

**LINK**

S46203 ASP 46 Piston & Liner

Price: £37.04 (Including VAT at 20%

[Engine Doctor]

Hi Not all the asp cylinders fit the OS counterpart. The SC / ASP 32 does  fit the OS 32 SX which was I believe the first of the OS engines that shed the plating when production moved to Tiawan years ago. I have never had an SC / ASP or a Magnum shed the plating ? OS definitely shot themselves in the foot then and Ripmax repaired engines FOC . Unfortunately the repaired engines very quickly went the same way . I'm not sure they do the repairs anymore .

Edited By Engine Doctor on 27/02/2019 17:16:26

[Braddock, VC]

Faint heart never wotsit fair maiden, ask Ripmax if they can fix it, I had a donkey's years old 10 fp and a 46 fx with duff liners, phoned up and they renewed both the liners and pistons for the cost of postage to them. Can't remember when but it was after production of both ceased.

It was a well known fault. Try e-mailing OS direct (it's free isn't it), if ripmax don't honour their responsibility, they just might do it.

Edited By Braddock, VC on 27/02/2019 19:24:11

[MikeQ]

Hello

I'll try Ripmax re a freebie but it looks like JEN actually have the right spares. Emailed them and they came back confirming.

thanks for the feedback and advice re fuel.

ill let you know how it goes.

cheers

mike

[Doug Campbell]

I am curious about the comments for Duraglow. I like many others have used it for years without problems. What makes a fuel more modern?

[Nigel R]

synthetic oil and not castor I would imagine

edit: possibly meaning the type of synth oil, as well as any additives used

Edited By Nigel R on 28/02/2019 09:22:00

[Jon H]

Posted by Doug Campbell on 28/02/2019 08:10:06:

I am curious about the comments for Duraglow. I like many others have used it for years without problems. What makes a fuel more modern?

Duraglo was developed before i was born i think. so there's that!

From the point of view of the engine though its the 6% castor that is a bit of a problem. It varnishes the piston and generally makes a mess of things. The varnish on the piston can screw up the fits causing the hot runs mentioned by extra slim earlier. In the case of a 4 stroke, especially ones over about a 90 or 120 size the castor cooks onto the exhaust valve in the very short time. This can make it stick, or leak, or just restrict the flow.

Modern synthetic oils are very good and castor really has had its day.

[MikeQ]

I started off using GX-5 or GX-10 Expert Mix back in the last century!

Does the castor not give some protection against lean runs ...on sub .60 two strokes per se.

No experience of 4Strokes.

PS I was brought up on Diesels and still use them regularly for FF competition, sport and a bit of CL flying and even in some RC converted FF models. So gunk and mess are all part of the fun for me ... I love the smell of Diesel in the morning!

Edited By MikeQ on 28/02/2019 09:46:16

Edited By MikeQ on 28/02/2019 09:48:07

[Jon H]

Posted by MikeQ on 28/02/2019 09:42:12:

I started off using GX-5 or GX-10 Expert Mix back in the last century!

Does the castor not give some protection against lean runs ...on sub .60 two strokes per se.

 

No, it dosent.

Just to clarify this though. An engine tuned lean is an engine tuned with a mixture that is too lean for maximum power. This will result in an rpm drop so an engine can never really run too lean as it will suffer loss of power, slow down, and then stop due to a lack of fuel. This all happens within about 3-4 seconds. An engine tuned for optimum performance may still over heat due to poor cowling design or the throttle jocky leaving the engine flat out all the time. Many engines lack sufficient surface area to cool themselves at maximum power and they wont wear it indefinitely. This is especially true if all the cooling fins are clogged up with congealed castor and dust! i would say that 90% of 'lean runs' are actually straight up overheating due to inadequate cooling and throttle management.

If we assume that the old 'it will protect against a lean run' is actually 'it will protect against overheating' then we are starting to get a little more accurate.

In the old days synthetic oils did not have the heat resistance of castor and could burn off under certain circumstances. Due to the less than spectacular fits of pistons and cylinders etc the varnish and general gloop of castor did not really cause a problem so it was all good. In modern (last 30 years at least) engines tolerances are much closer and modern synthetic oil is easily able to handle the heat so there really is no need to use castor.

When it comes to overheating i often get asked how hot is too hot and i always say that you should be able to touch the engine but not hold it. If you can touch it for a half second without being branded then you are doing fine. Just think about how hot the engine in your car is, our engines run about the same temperature as that so 90 or 100'c is nowhere near the danger zone.

It should also be noted that engines run far hotter on the ground than in the air. They are air cooled after all and there is more air in the sky so long ground runs are not really a good idea.

And yes, i love the smell of a diesel  

 

Edited By Jon - Laser Engines on 28/02/2019 10:11:14

[MikeQ]

Hi

yes ... that all makes a lot of sense. I must say, that's one thing I've often done is check the cylinder temp by touch. I'm pretty fastidious about keeping my motors clean and cleaning my models down ... ever since the diesel soaked front end of my FF Tomboy snapped off when I was 8yrs old. Perhaps spending and entire summer holiday trying to learn how to start Diesels while bolted into a non fuel proofed balsa model using stale fuel explains it!

Thanks for the explanation and I'll check out the fuel advice too. I'll go the spares route with JEN ... then I may be back in touch for some other pointers.

Cheers

Mike