O.S FS 120 SP Spark ignition MÜLLER

[Bitmaster69]

must say, the engine is the 3rd Version of the SP, the latter two had Valve problems, sorry guys, they never ran well. The 3rd version does.

I am mixing my own premium fuel ever since it it alwyaysd flew on 20-20-60, nitro-oil-methanol. Less oil gives more rpm, no doubt, but you wear out the engine too quickly. This engine loves fuel, 2.5mm diameter all the way and 750ml per 10min

of high nitro yummie mummy :) . My idle rpm sound better than the Harley I used to have, no doubt, with glow !

[Bitmaster69]

Hi there, still flying this engine on my TopFlite P-47 D23 Thunderbolt.

Ther sound of this engine is just BEYOND all other s I have ever heard in real when

it turns an APC 15x8 @ 9.400 in idle. When strafing the runway at full bore it must be in full supercharhged mode at 10-12.000 rpm when coming out of a gentle dive, scale like and hammering the piston with 2.5 bar extra ooomps , I just love it.

This engine is a real diamond, used to have 3 of them, 1 remains roaring the skies :)

[Bamchucknorris]

what specific ignition module do you use

[mikebanks1]

Hi, I bought a 120sp when they first came out, and it has never ran well.

What do I need to make it spark IG.

Am I right in thinking you are now running it WITHOUT Nitro?

Best regards

Mike

[otisdaman22]

What is your timing set at for this engine. Would it be different for a Saito 65 for example. Most gas engines are set at 28 degrees. Does run sweet!

[eulboyington]

All MÜLLER spark ignition ( single and Twins ) must be set at 0° TDC, the electronic chipset manage the advance timing. All my 4 stroke engines, single and twins, are running with spark ignition. As my Friend, I will never come back to glow !

[7bikerboy7]

hey buddy I have a question...i have a 120 surpass 4 stroke engine im breaking in, When i try to flip start it the prop nut comes loose every time, what should i do?

[oakleymac1]

That usually happens when a little too much fuel is in the cylinder

[30GB]

add water cooling and put it in a rc or boat and you got a super charged rc 4 stroke

[mobeltrao]

Where do you get the wire plug for spark plug VR2? I am not getting to find?

[Ricmcspeedy987]

Is it true that they are supercharged?

[eulboyington]

Yes, It was a real supercharged engine with ROOTS compressor.

O.S no longer build this engine, it's now collector / vintage !

[incubrian]

do you get a lot of oily residue from the exhaust after running the engine on your model/test stand?

[framelocator]

Ok,so your engine(s) have electronic ignition but run still on methanol and 18% lubrication?

Sounds like the engine is much more reliable with the spark plug instead of a glowplug?

[eulboyington]

>Ok,so your engine(s) have electronic ignition but run still on methanol and 18% lubrication?

YES, conventional methanol based fuels used with not less than 18 % synthetics lubricants.

Nitromethane is no more necessary

>Sounds like the engine is much more reliable with the spark plug instead of a glowplug?

YES, better sound with increase power, less consumption - 15 per cent !

Olivier

[framelocator]

When adding nitro to the glowfuel,will the sparkplug be destroyed?

I couldn't find any info regarding the harzards of adding nitro to the fuel in combination with the spark ignition.

Will the fuel efficiency improve with a spark ignition?

Thanks in advance!

[eulboyington]

With electronic ignition and sparkplug, nitromethane is no more necessary, but you can use 10 nitro fuels with no problem.

I fly all weekends with single and twins 4 stroke model engines all spark ignition converted with absolute 100 % satisfaction

Best results - power, idle, corrosion protection - with LABEMA M 1.2 4 stroke model fuels, avaiable in France.

Oliver

[eulboyington]

I said : you can use 10 per cent nitro fuel with no problem

[eulboyington]

With 1/4-32 micro spark plugs :

I tested all world avaiable micro spark plugs.

Best results, long life, obtained with RIMFIRE VR2 and VR2L (short and long reach)

U.S.A products avaiable from LuElla & Roland MORISSON,

MORISSON & MARVIN compagny,

BENTON City U.S.A

Excellent service and relationship.

Oliver

[Biggles1966]

thanks!

/Thomas

[TurboLover336]

I have one too, Mine likes a 15 X 8 - 15 X 10. the larger than specified prop seems to level it out a little. tuning is touchy, and the supercharger tends to load with fuel at low RPM making tuning frustrating as well if you are unaware of that issue.

tune wide open, one or two clicks at a time counting to 4 between adjustments, there is a lag before the adjustment takes effect.

it is not for casual flying. it is for air dommination

[Biggles1966]

Nice, I have also a OS 1.20 SP engine. I have problems with it. It dosen´t work well, I have tried everything, upgrade carburator and intake. I run on 25% nitro 20% oil and a 14x14APC. mayby a ignition system will fix it? Have you had any problem with the engine before?. What propeller size are you using?

Sorry, pressed the wrong button(spam) before.

/Thomas

[eulboyington]

Hi thomas,

I think 25 per cent nitro is too much for this 4 stroke engines, and it needs only high quality synthetics 18 % oil, no castor oils.

I solve a lot of running problems with spark ignition on a lot of high performance model engines as YAMADA 140 and 160 DZ

Oliver

[Biggles1966]

Nice, I have also a OS 1.20 SP engine. I have problems with it. It dosen´t work well, I have tried everything, upgrade carburator and intake. I run on 25% nitro 20% oil and a 14x14APC. mayby a ignition system will fix it? Have you had any problem with the engine before running on gas? Is it same power in it now than with nitro?. Propeller size?, oil %? are you using?

/Thomas

[evilamish]

What do you profer nitro or gas and were did you get ignition set up

[eulboyington]

The methanol / synthetics oils are kept because these engines can't work with gas (conrod with sleeves bearings, and so on )

With this électronic ignition, nitromethane is no more necessary. All my 4 stroke mono, and twins engines are equipped since 3 years !

All details about this ignition modules can be seen on the web site of the manufacturer : Günter MÜLLER

mueller-modellbau-technik, and English version on ANLEITUNG-ANBAU, on the left of the main web page

[fre2fly]

cool. is that supercharged? and is that y it runs so crap

[eulboyington]

Yes, it's Supercharged engine ; the ignition module works also fine on others mono cylinders and twins, with RIMFIRE micro Spark Plugs.

Olivier