Fruitless flipping...almost

[Tim Mackey]

LOl I think I will join you m8
How on erth anyone can think that damage may be done by merely removing a rocker cover is beyond me...so I have butted out of this one,as you say....we have suggested things to try...and can do more :)

[Flanker .]

Guys do not get huffy ! My point was that a newbie will not find much in their rocker cover that they will understand without tools/gauges etc and that with a new Motor one should return it to the shop if one feels that there may be a problem.
A new motor is gurenteed (if we havn't left tool marks on it's screws... )

This bump business is not a "Flanker the w..." thing it is a procedure that I learned in the hallowed pages of RCM&E 25 years ago and have followed ever since. You will not find me in the pits cursin and flickin or starter churnin. My motors start first time every time and I fly, fly ! (except for when they don't.)

Aslan your fuel point is a good one, four strokes do like four stroke fuel with 10% nitro for sure.

I have followed this thread with great interest as I have an OS 46 surpass that seems to be much like Tony's I have banged on about how I start it earlier on but I have hopes that a real fourstroke Guru will come on line and solve all our troubles by telling me & Tony that we have our Johnson rods fitted backwards...

[Flanker .]

Oh yeah, Timbo find where I said that DAMAGE would happen if Tony removed his rocker cover coz I can't ! That would be a very silly thing to say. (even for a vain oppinionated, know it all smart arse like me ) :) :) .) (am I back in the hugging circle yet?)

[Tony Patman]

OK, I've been on holiday and haven't had the chance to get down and smoky again yet.

I have no intention of dismantling my engine.

I bought a starter yesterday, but I think it might be faulty. Running it off my mains transformer (13.8v, a bit higher than the rated 12v), it needs a poke to get it rotating and it seems to have minimal torque.

What, pray, is a Johnson rod?

[Tim Mackey]

I doubt that your mains transformer can supply the current required to turn the starter under load...they pull a LOT of Amps.
Johnson rods? .....I think he may be pulling your Johnson :)

[Tony Patman]

The transformer supplies 3A steady, 5A max. At 13.8v this is a maximum of about 70W so, indeed, not a lot. Time to invest in a battery...

[Flanker .]

A Johnson rod is the very expensive thingie that the mechanic shows you before sighing and charging you are fortune!

(oh and they are NEVER in stock either)

[Malcolm Fisher]

Tony, I use a small twelve volt motor cycle battery of 4 Ampere hour capacity and this will usually do all that I need for a flying session. A bigger capacity could be beneficial if you have engines which are reluctant to start.

With mine, i have to make sure that it is in a reasonable state of charge before the session and have occasionally used a connection via the cigar lighter in my car to charge en route to the field.

[Aslan]

Oh my God.....Please stop mentioning dismantling an engine,it was never suggested...
ever ever ever ever.(I can't believe I'm posting this:):):))Oh sure while I'm here,Yeah
Tony,you need a 12v battery.Most flyers would have one in their field box.

[glbiggles]

Using a Power supply to drive starter is unlikely to work. I've tried a 10A unit on my starter after reading this, and it was a bit slow. I generally use a 7A Gell Cell (Motorbike battery) to drive my starter and sometimes on a 120 it struggles a bit, so I drag out my electric flight charge battery (about100A) and it spins easily.
I have a number of 4ST from OS26 to YS140 and find that it is difficult to start any of them by flicking, but most start with one touch of a starter, after turning over for a few secs on full throttle WITHOUT connecting Glo Plug.Then back to low throttle connect plug turn with starter and bang they go.

[Steve Hargreaves - Moderator]

Since nearly everyone in modelflying seems to have contributed to this thread I thought I might as well join in!!!!

A bench power supply will never run a starter.....starters pull 10's of amps & the internal resistance is simply too high to allow this current to flow. A 7A/hr (or thereabouts) lead/acid battery is the way to go (although I do know of people who use a 10 cell flight pack strapped to their starter for a fully portable unit & this works well although the number of starts are limited due to the relatively low capacity)

First point....I believe the motor in question here will be ringed so turning it over slowly by hand is unlikely to reveal much compression. The dykes ring used in our motors relies on some pressure from above the piston to expand it slightly against the cylinder wall & create a good seal. Turning it slowly doesn't provide the pressure to make it work properly so a good flick or even better a starter is essential. Being new & having nothing bedded in yet only makes matters worse.

5 turns open sounds way way too much on the needle. try 2.5 & see how you get on. If the motor still stops then simply leave the glow clip in place & try & build up some running time. Once the motor starts to bed in (should only take 30 mins running or so) then the compression seal will improve & you can start to lean out the needle until the motor runs smoothly....then try & take the glow clip off.

Final thought...as this is an SC (I think I read that earlier) motor they are pretty much identical to ASPs which I run. If you would like a copy of the (excellent) instructions that come with an ASP (written by the late Paul Landels of Just Engines in real English) then please drop me a line & I'll send you a copy.

Happy twirling......!!!

[Tony Patman]

Thanks Steve and all the contributors to this thread. Not only has it helped me enormously to understand what I'm doing, it being on this forum makes it a resource for all in the same boat. Hurrah for the Web!

[Steve Hargreaves - Moderator]

You know what they say....".....there are no strangers in aeromodelling...just friends you haven't yet met...."

Tell me (cos I'm keen to know!!!!)....is your engine up & running now or have you banished it to the darkest corner of the cellar for a few days (this can work in certain circumstances!!!!)

[Danny Fenton]

Ahhh Steve gets slowly drawn into Tony's Cellar, never to be seen again......

[Tony Patman]

I haven't had much time over the past couple of weeks, so it's sitting on a shelf waiting.

[Ian Jones]

I have had an SC52 FS for about 3 years. It's been great but the first start of a session has been critical.

The way I start mine is similar to some of the other suggestions but with a small variation. The issue is knowing when the engine is suitably primed and it's done by listening very carefully:

1. Fuel up
2. Set main needle 2.5 turns out
3. Turn the prop by hand until it has just gone past compression (makes it easier for the starter to spin up from this position)
4. Fully open throttle
5. Apply the starter (without glow clip attached) and listen, if you can see the fuel supply to the carb watch that too.
6.When the fuel reaches the engine the sound of the engine turning will become more muffled and the lubrication this provides will cause an increase in the speed it turns over. (If you can see the fuel being drawn along the fuel pipe into the carb that will give you a good clue this is about to happen.) As soon as this happens stop turning over the engine and...
7. .... immediatly apply the glow clip and turn over the engine with the electric starter.
8. At this point you should be smiling!
9. Follow previous advice on running in and setting needles.

Sometimes I don't use this engine for a while and I forget to follow this routine, it doesn't get properly primed and it will not start.

As mentioned elswhere though, the cautionary note is not to hydraulically lock the motor. If at any point you suspect that it is locked or the starter stops turning the engine remove the the glow clip and follow the advice already given for a locked engine. NEVER touch the prop with the glow clip connected.

Hope this is a useful addition to the good advice already offered.

[Myron Beaumont]

Interesting cos i've run in my FS52 & following the destructions I have no problems Yet ! It's my first 4 ST & I have never used an electric starter .I do have a problem finding the compression stroke cos it's not fully run in I presume .Seems like i'm not the only one .I make sure there is fuel in the crankcase (wet) attach glow & flick, no problem.But that is on the bench !I shall refer to your advice if it doesn't work in situ.Thanks again for advice . Myron.

[Alan Shipley]

Tony, think you said that you was using a three blade prop, well forget that at this stage and put correct size two blade or bit bigger. Engines will not start or run unless the mixture is correct. Starting needs to be wet but carb set not too rich. It always makes me smile when I see starters churning away. A starter held on at idle will not start the engine as it is running to fast at idle setting, you just need to blip the spinner. Hope you know you need a spinner on the prop. A good way to get your main needle setting is to get engine wet where it will fire with needle closed and as it keeps firing turn out needle till it runs well and smooth.

[Myron Beaumont]

Am I correct in thinking that when 4strokes came into usage they were flicked the wrong direction against the firing point so as to give impetus in the correct direction ? {or am i so senile I'm getting it wrong ? Myron .( I daren't try it without further advice incidentally without protection ,They didn't have locknuts then I do remember that much.)

[Tim Mackey]

many people still do it that way now.....

[Peter Roberts]

Having read tis thread and NOT an engineer I have to say that usually I have bought and started OS 4 strokes straight from the box with no running in on 10% nitro.

I've left the main needle and low end as set by the manufacturer. I attach pressure feed to tank. Then I open the throttle fully with the tank full and with no glo on cover the air inlet with a finger and wind the prop twice anti clockwise. I then shut the throttle to idle position, apply the glo plug and keeping hands arms and fingers clear apply the starter. It usually starts first time every time.

[Alan Shipley]

Hi Tony, how are you getting on with starting and running that engine? Have you used any other engine?

[Tony Patman]

I've been too busy to have a chance to fiddle again yet. Maybe on Saturday...

[Peter Miller]

I am surprised that you had the rouble, mind you, as every says, 5 turns is way too much.
I use nothing but SC engines unless I get a bargain on eBay. I never have any trouble with them. I currently have 2 30 FS and a 52 FS, about 6 32s and several 15s, all SCs.
On plugs, I use nothing but Taylor Standard long reach plugs and never, ever have any plug trouble on two stroke or four strokes. Have done for more years than I care to remember. The happen to be much cheaper too. When I suggest this to clubmembers they tend to change over and live happily ever after.

[Tony Patman]

Update
So, finally I got some time over the weekend.

Sensibly I got the engine outside this time. I think I'm getting the hang of starting it now, but I still wouldn't call it easy sometimes.

I noticed slight bubbling of oil from a point at the seal of the rocker cover.

The nut locking the carb. barrel came loose and I had to tighten it again. The optimum main needle setting seems to be about 1 1/4 turns open.

Now I'm trying to set the idle needed. I had the engine purring like a kitten at a steady idle, then it conked out and wouldn't start again; but the fuel tank was virtually empty and probably my glow igniter had expired!