OS 120 four stroke questions?
09-06-2008, 11:47 AM
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OS 120 four stroke questions?
I just purchased a four year old OS Max FS-120 Surpass -E four stroke that supposedly only was broken in with three tanks of fuel for $120 and I had a few questions.
-What's the Surpass E stand for?
-How much compression should I feel when turning the engine over by hand?
-What condition does it look in from the below photos?
-If this runs good, is this a good deal?
-Is this a good engine for a Goldberg Ultimate bipe?
-What's the Surpass E stand for?
-How much compression should I feel when turning the engine over by hand?
-What condition does it look in from the below photos?
-If this runs good, is this a good deal?
-Is this a good engine for a Goldberg Ultimate bipe?
09-06-2008, 12:05 PM
#2
RE: OS 120 four stroke questions?
I think your just showing off your good deal
Unless the previous owner did a pretty thourough cleaning job on that engine I would say his aproximation of use is accurate. My four strokes mufflers are solid brown after 10 or so tanks of fuel. Yours just has a few spots. The guy probably could have goten $200 for the engine. Compression feals different on 4 strokes than it does on 2 strokes. Also a ringed engine gaines compression as it warms up. So, do not be alarmed that it feals like it has less compression than a .46 2 stroke. Warm it up at a fairly rich setting and then shut it down and then feal the compression. Or put some fuel in it and heat it up with a heat gun.
Pull the valve cover off and observe the rocker arms as you rotate the crank shaft to ensure a lifter has not gotten stuck after sitting for so long too.
Unless the previous owner did a pretty thourough cleaning job on that engine I would say his aproximation of use is accurate. My four strokes mufflers are solid brown after 10 or so tanks of fuel. Yours just has a few spots. The guy probably could have goten $200 for the engine. Compression feals different on 4 strokes than it does on 2 strokes. Also a ringed engine gaines compression as it warms up. So, do not be alarmed that it feals like it has less compression than a .46 2 stroke. Warm it up at a fairly rich setting and then shut it down and then feal the compression. Or put some fuel in it and heat it up with a heat gun.
Pull the valve cover off and observe the rocker arms as you rotate the crank shaft to ensure a lifter has not gotten stuck after sitting for so long too.
09-06-2008, 01:14 PM
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RE: OS 120 four stroke questions?
Well, I want to find out if it's good to go right away to find out, so I want to test run it but don't know exactly how.
I have Cool Power 15% all synthetic. Is this good to run it with?
Also, to test run it, if I bolt it down to the end of a 2x4 with a taped down fuel tank behind it and two fuel lines, one feed and the other vent, and C-clamp the board to a test stand, would this be a good way to test it?
And how do you prime a four stroke?
Thanks.
I have Cool Power 15% all synthetic. Is this good to run it with?
Also, to test run it, if I bolt it down to the end of a 2x4 with a taped down fuel tank behind it and two fuel lines, one feed and the other vent, and C-clamp the board to a test stand, would this be a good way to test it?
And how do you prime a four stroke?
Thanks.
09-06-2008, 01:22 PM
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RE: OS 120 four stroke questions?
I would not use a c-clamp to tie the 2x4 down ..use a couple of screws instead.....I run a satio 180 on Omega 15 % just fine...
fuel lines just like a 2 stroke in this case....
either put your finger over the muffler and turn the prop through or open the throttle and put your finger over the c arb and turn the prop through
fuel lines just like a 2 stroke in this case....
either put your finger over the muffler and turn the prop through or open the throttle and put your finger over the c arb and turn the prop through
09-06-2008, 01:24 PM
#6
RE: OS 120 four stroke questions?
To prime the engine do this. Without the glow starter on, open the throttle wide open. Cover the end of the muffler, or the carb barrel, and flip the engine over by hand. When you see fuel enter into the carb take your finger off the carb and flip it over 3-4 more times. Now reduce the engine to idle and put the glow starter on. Now start the engine. It should fire up in a few flips of the prop.
Ken
Ken
09-06-2008, 02:09 PM
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RE: OS 120 four stroke questions?
I would definitely recommend getting an electric starter if you do not have one already. If you plan on putting the engine in a cowled plane (which it sounds like you are), it may be difficult to reach the carb to prime. The starter should make quick work of starting the motor even without a prime.
In my personal experience, my 4-strokes start from cold after a few seconds of hitting them with the starter. [8D]
In my personal experience, my 4-strokes start from cold after a few seconds of hitting them with the starter. [8D]
09-06-2008, 02:19 PM
#8
RE: OS 120 four stroke questions?
ORIGINAL: Spitfire222
I would definitely recommend getting an electric starter if you do not have one already. If you plan on putting the engine in a cowled plane (which it sounds like you are), it may be difficult to reach the carb to prime. The starter should make quick work of starting the motor even without a prime.
In my personal experience, my 4-strokes start from cold after a few seconds of hitting them with the starter. [8D]
I would definitely recommend getting an electric starter if you do not have one already. If you plan on putting the engine in a cowled plane (which it sounds like you are), it may be difficult to reach the carb to prime. The starter should make quick work of starting the motor even without a prime.
In my personal experience, my 4-strokes start from cold after a few seconds of hitting them with the starter. [8D]
09-06-2008, 03:12 PM
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RE: OS 120 four stroke questions?
I just checked on Tower's page to see if I could figure what Surpass means and found it. It says
"Surpass" refers to this series gaining 30% more power than the previous
FS series.
"Surpass" refers to this series gaining 30% more power than the previous
FS series.
09-06-2008, 03:14 PM
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RE: OS 120 four stroke questions?
Tower's page also says
When choosing fuels for this engine, the modeler must be sure to
select a fuel with at least a 18% lubricant content.
Does anyone know if Cool Power %15 does?
Thanks.
When choosing fuels for this engine, the modeler must be sure to
select a fuel with at least a 18% lubricant content.
Does anyone know if Cool Power %15 does?
Thanks.
09-06-2008, 03:16 PM
#11
RE: OS 120 four stroke questions?
ORIGINAL: cappaj1
Tower's page also says
When choosing fuels for this engine, the modeler must be sure to
select a fuel with at least a 18% lubricant content.
Does anyone know if Cool Power %15 does?
Thanks.
Tower's page also says
When choosing fuels for this engine, the modeler must be sure to
select a fuel with at least a 18% lubricant content.
Does anyone know if Cool Power %15 does?
Thanks.
09-06-2008, 04:06 PM
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RE: OS 120 four stroke questions?
Make sure that you tighten ALL of the cap screws.
After the first runs, the cap screws tend to loosen and you'll get hot fuel/castor leaking all over the crankcase and cylinder head in amounts that stain the engine casing.
You can see that this happened already with your engine to a small degree.
If you retighten the cap screws ( be careful NOT to strip them though! ) this will stop and the engine should remain fairly clean, even if you are using a castor mix.
BTW: Cool Power 10% or 15% works fine on that engine, though I prefer the 15% for easier to set needles and more reliable idle with a light prop.
After the first runs, the cap screws tend to loosen and you'll get hot fuel/castor leaking all over the crankcase and cylinder head in amounts that stain the engine casing.
You can see that this happened already with your engine to a small degree.
If you retighten the cap screws ( be careful NOT to strip them though! ) this will stop and the engine should remain fairly clean, even if you are using a castor mix.
BTW: Cool Power 10% or 15% works fine on that engine, though I prefer the 15% for easier to set needles and more reliable idle with a light prop.
09-06-2008, 04:19 PM
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RE: OS 120 four stroke questions?
ORIGINAL: RCKen
I run Cool Power 15% in all of my engines, 2 and 4 stroke.
Ken
I run Cool Power 15% in all of my engines, 2 and 4 stroke.
Ken
09-06-2008, 04:38 PM
#15
RE: OS 120 four stroke questions?
There is only one "Cool Power". Cool Power is green in color and has synthetic lubricant in it. Morgan fuels does have blends that have castor in them, but right now I forget the name of that blend.
Ken
Ken
09-06-2008, 07:25 PM
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RE: OS 120 four stroke questions?
It does have an early rocker arm cover on it so it looks like one of the older engines. Not A big deal if it runs well though. I would ask Bill Baxter about it though. He is over in the glow engine forum. Today the 1.20 with a pump is around 400 dollars so if your engine runs well you got A great deal. Without pump it runs about $320.00, I think the E stands for the model without the pump?? If the engine hasn't been cleaned you can look at the exhause valve from the port and see if it's full of gunk to get an idea of use. Today with the crock pot cleaning it's often hard to tell anything by looking at the outside of an engine. Light that puppy up and let us know how well it runs.
09-06-2008, 08:32 PM
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RE: OS 120 four stroke questions?
ORIGINAL: Gray Beard
It does have an early rocker arm cover on it so it looks like one of the older engines. Not A big deal if it runs well though. I would ask Bill Baxter about it though. He is over in the glow engine forum. Today the 1.20 with a pump is around 400 dollars so if your engine runs well you got A great deal. Without pump it runs about $320.00, I think the E stands for the model without the pump?? If the engine hasn't been cleaned you can look at the exhause valve from the port and see if it's full of gunk to get an idea of use. Today with the crock pot cleaning it's often hard to tell anything by looking at the outside of an engine. Light that puppy up and let us know how well it runs.
It does have an early rocker arm cover on it so it looks like one of the older engines. Not A big deal if it runs well though. I would ask Bill Baxter about it though. He is over in the glow engine forum. Today the 1.20 with a pump is around 400 dollars so if your engine runs well you got A great deal. Without pump it runs about $320.00, I think the E stands for the model without the pump?? If the engine hasn't been cleaned you can look at the exhause valve from the port and see if it's full of gunk to get an idea of use. Today with the crock pot cleaning it's often hard to tell anything by looking at the outside of an engine. Light that puppy up and let us know how well it runs.
What's Bill Baxter's username? Can't find him under that username and there are alot of B Baxters for full name search.
By the way, what's different about the rocker arm cover? Mine looks exactly the same as the one on Tower's page for the current 120 Surpass from what I can tell
http://www2.gpmd.com/imagel/o/losmg0930.jpg
09-06-2008, 09:11 PM
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RE: OS 120 four stroke questions?
ORIGINAL: cappaj1
By the way, what's different about the rocker arm cover? Mine looks exactly the same as the one on Tower's page for the current 120 Surpass from what I can tell
By the way, what's different about the rocker arm cover? Mine looks exactly the same as the one on Tower's page for the current 120 Surpass from what I can tell
09-07-2008, 02:54 AM
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RE: OS 120 four stroke questions?
Bax is B.Baxters user name.
your 120 is the same basic non pumped model as the one being sold on towerhobbies the black box is a indication yours is a bit older, the newer version has a blue box, but its the same engine the SE hasn't yet changed at all.
the spIII is the pumped version with the newer updated carb, and has rust resistant bearings, and a black anodised cap not really that much different than your deal.
as for fuel as long as the oil content is 18% and the nitro is 5-15% than any fuel will do, sythetic oil is fine for any engine,I use alot of Powermaster 10% in all my engines most of which are 4st 15% nitro is going to get a smoother run but the 10% I use works well enough on all my OS engines.
your 120 is the same basic non pumped model as the one being sold on towerhobbies the black box is a indication yours is a bit older, the newer version has a blue box, but its the same engine the SE hasn't yet changed at all.
the spIII is the pumped version with the newer updated carb, and has rust resistant bearings, and a black anodised cap not really that much different than your deal.
as for fuel as long as the oil content is 18% and the nitro is 5-15% than any fuel will do, sythetic oil is fine for any engine,I use alot of Powermaster 10% in all my engines most of which are 4st 15% nitro is going to get a smoother run but the 10% I use works well enough on all my OS engines.
09-07-2008, 04:24 AM
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RE: OS 120 four stroke questions?
Why do they sell a pumped version of this engine?
Is it common to use a pump on this size four stroke?
When is a pump required?
How will I know if I need one?
Can someone send me a link to a typical pump for this engine on Tower's site?
Is it common to use a pump on this size four stroke?
When is a pump required?
How will I know if I need one?
Can someone send me a link to a typical pump for this engine on Tower's site?
09-07-2008, 02:55 PM
#24
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RE: OS 120 four stroke questions?
why?
pumped engines run better at all attitudes,vertical,inverted flight etc...and feed the fuel at a constant pressure.
4st engines run fine without pumps, there not required for good running as long as your tank is in the regular position behind the firewall.
again a pump is really not required,when setting up the plane with the tank in the standard position.
they are only necessary when you place your tank at the center of the plane on the CG,or when your doing extreme acrobatics, and helps to make sure the fuel is fed at a consistant rate,when the tank is positioned far away the muffler pressure is not always sufficent enough to push the fuel to the engine.
your engine will run fine with out one, but Perry makes a oscillating pump http://www3.towerhobbies.com/cgi-bin...?&I=LXDG61&P=0 if your obsessed with adding a pump,adding a after market pump just adds more plumbing and requires more attention to the tuning process,getting the pressure dialed in and the engine running smooth.
pumped engines run better at all attitudes,vertical,inverted flight etc...and feed the fuel at a constant pressure.
4st engines run fine without pumps, there not required for good running as long as your tank is in the regular position behind the firewall.
again a pump is really not required,when setting up the plane with the tank in the standard position.
they are only necessary when you place your tank at the center of the plane on the CG,or when your doing extreme acrobatics, and helps to make sure the fuel is fed at a consistant rate,when the tank is positioned far away the muffler pressure is not always sufficent enough to push the fuel to the engine.
your engine will run fine with out one, but Perry makes a oscillating pump http://www3.towerhobbies.com/cgi-bin...?&I=LXDG61&P=0 if your obsessed with adding a pump,adding a after market pump just adds more plumbing and requires more attention to the tuning process,getting the pressure dialed in and the engine running smooth.
09-07-2008, 03:34 PM
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RE: OS 120 four stroke questions?
ORIGINAL: bigtim
why?
pumped engines run better at all attitudes,vertical,inverted flight etc...and feed the fuel at a constant pressure.
4st engines run fine without pumps, there not required for good running as long as your tank is in the regular position behind the firewall.
again a pump is really not required,when setting up the plane with the tank in the standard position.
they are only necessary when you place your tank at the center of the plane on the CG,or when your doing extreme acrobatics, and helps to make sure the fuel is fed at a consistant rate,when the tank is positioned far away the muffler pressure is not always sufficent enough to push the fuel to the engine.
your engine will run fine with out one, but Perry makes a oscillating pump http://www3.towerhobbies.com/cgi-bin...?&I=LXDG61&P=0 if your obsessed with adding a pump,adding a after market pump just adds more plumbing and requires more attention to the tuning process,getting the pressure dialed in and the engine running smooth.
why?
pumped engines run better at all attitudes,vertical,inverted flight etc...and feed the fuel at a constant pressure.
4st engines run fine without pumps, there not required for good running as long as your tank is in the regular position behind the firewall.
again a pump is really not required,when setting up the plane with the tank in the standard position.
they are only necessary when you place your tank at the center of the plane on the CG,or when your doing extreme acrobatics, and helps to make sure the fuel is fed at a consistant rate,when the tank is positioned far away the muffler pressure is not always sufficent enough to push the fuel to the engine.
your engine will run fine with out one, but Perry makes a oscillating pump http://www3.towerhobbies.com/cgi-bin...?&I=LXDG61&P=0 if your obsessed with adding a pump,adding a after market pump just adds more plumbing and requires more attention to the tuning process,getting the pressure dialed in and the engine running smooth.
