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O.S. GF40 4st gas

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Old 07-07-2013, 06:21 PM
  #51  
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Default RE: O.S. GF40 4st gas


ORIGINAL: TonyBuilder

Day five on the OS49, I'm done! This engine has been nothing but a big pain and disappointment. There is no way I'm putting two of these in my B-25.
It was running good yesterday, then today I could not get it started. Had to put another new plug in it. Then it started. Was running ok but still needed some low end adjustment, hardly turned the needle, ran it some more, stopped it to do more adjustments, then started it again. It ran then back fired spun the prop and I could not get it started again, I'm done with this engine. I have hade 6 DLE's and they all are '' mount, flip, and fly'' with miner adjustments to the hi end as she broke in. So I would not recommend this engine to anyone that does not have a lot of time and patients to mess with it. I'm no gas Expert so maybe I'm not qualified to run this type of engine.
I will let this engine sit for a bit, going to send the unused one back and get two DLE35R for my B-25. I may try again on the OS40 in my cub, or sell it. Anyone want a great deal on one of these, only got about 18oz threw it! PM me.
TB
Sorry, not to offence you, but it sound you do not have much experience tuning carbs from the scratch. DLE engines come with carb settings where you really don't need to adjust anything. DLE engines working well right from the box.
I have 3 Saito 4-stroke gas engines and recently got OS GF40, which is running wery well on original carb settings, just a bit too rich. Recently set low needle a bit down and I got nices running 4-stroke engine with very nice low to high rpm response, although I have to admit it is very responsive on throttle changes. The long experience tuning all my Saito carbs helped me to handle gf40 w/o problem.
Please, do not give up on this engine. Read a few forums regarding tuning carbs. 4-stroke engines are more sensitive on carb settings compare to 2-stroke engines. Keep it in mind and be a bit more patient :-).
I wish you succeed with gf40.
Have a great time.
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Old 07-07-2013, 09:31 PM
  #52  
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Default RE: O.S. GF40 4st gas

I will agree, the DLE's are a bit simpler to deal with, I've got a whole fleet of them- 20cc, 30cc, 35ra, & 50cc, and they all run good.
The OS is not quite as easy to work with. I tend to break my engines in a little different than most, just a touch more oil and run the crap out of them, NO mercy!
I have yet to have a bad runner, EVER, seat the rings fast as possible with good cooling air.
I don't quite get the need to keep changing the plug for every day of running your engine, figure out the cause of fouling and fix it, be it oil ratio/rich mixture or whatever. I don't think I would be so quick to condemn the engine, OS tends to get there stuff right for the most part. Now my big Saito FG-57T twin gas, it has about 15 flights and is apart for bearings, and the cams run bone dry, I have to pump oil into the breather and tilt the plane on its nose to oil the cams. As a glow engine, they (Saito), are fine. Gas tend to run less oil. The OS is much better thought out in the lubrication regard.

Keep fooling with it, it will work, try a little less oil in the fuel, I run 30-1 Stihl hp ultra, and it seems to like it.

Mark.
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Old 07-08-2013, 03:05 AM
  #53  
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Default RE: O.S. GF40 4st gas

Thanks guys, I am just frustrated and I know this engine can be tamed. I will reset the needle valves and start over. I had it very close then I guess I turned the low end to far, maybe one click and she was back to back firing. So very little adjustments and I will try again next week. TB
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Old 07-08-2013, 06:26 AM
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Default RE: O.S. GF40 4st gas

Patience, patience, patience
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Old 07-08-2013, 03:46 PM
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Default RE: O.S. GF40 4st gas

Remember, when you get it close, a screwdriver blade width is all it takes sometimes.

Mark.
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Old 07-11-2013, 09:17 PM
  #56  
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Default RE: O.S. GF40 4st gas

TB,
What is that springloaded doohickey on your throttle linkage and where do I get one or 3 or 4?

Dave
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Old 07-12-2013, 12:40 AM
  #57  
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Default RE: O.S. GF40 4st gas

RC I think it's these. I use them in some setups.
http://www3.towerhobbies.com/cgi-bin...?&I=LXYCH4&P=0
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Old 07-12-2013, 03:07 AM
  #58  
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Default RE: O.S. GF40 4st gas

ORIGINAL: RCJones

TB,
What is that springloaded doohickey on your throttle linkage and where do I get one or 3 or 4?

Dave
RCJones, they are the Sullivan ball connectors. The blue is 4-40 and the red is 2-56. I use ni rods so 2-56 is good for that. They allow for quick and easy removal of the engine. I have used them on all my engines for the past three years, no problems.

TB
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Old 07-13-2013, 04:07 AM
  #59  
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Default RE: O.S. GF40 4st gas

Thanks
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Old 07-13-2013, 10:41 AM
  #60  
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Default RE: O.S. GF40 4st gas

Today I brought the cub to try again. I reset the low end to 1-1/2 turns. Set the choke, flipped a few times till it popped. Then I used the starter and it started right up. Warmed it up a few min on the start stand, then put it on the ground and did some taxing. Ran solid, 7700rpm. I then taxied back in and killed the engine with the optical kill. About an hour or so later tried to start it and spent an hour and could not get it to pop or start. So the cold starts are good, it's the warm starts that's giving me fits. What are you guys doing for the cold and warm starts?

TB
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Old 07-14-2013, 11:59 AM
  #61  
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Default RE: O.S. GF40 4st gas

So I think I have the engine issues worked out. She is tuned well, running good and reliable. We did a test. First flight of the day she started right up with normal start up procedure. As soon as I landed and got to the plane I clamped off the fuel line. Then after about 30min we tried again. Seconds before starting I removed the clamp and started the engine with no choke. It started right up. Flew it then did the same. We tried again and it worked the same so we think the fuel tank is to high. I know it should not matter with a gaser but the center line of the tank where the line comes out is a good 2” higher then the carb so this is the only thing we can think of is that it is siphoning the gas and flooding the carb between flights. So I will lower the tank and try without clamping the fuel line and see what happens. At least I know what is wrong.

TB
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Old 07-14-2013, 07:57 PM
  #62  
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Default RE: O.S. GF40 4st gas

The tank in my plane, (Giant super sportster), is right in line with the carb and it's also a fairly small one too, 8oz.
The instructions say to leave fuel in the carb when your done for the day, when I do that it stinks up the plane room in the house. So I run it dry when i'm done now.
Hot restarts can be a little trying at times if hand starting, the electric starter works wonders here!

Mark.
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Old 07-15-2013, 06:19 AM
  #63  
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Default RE: O.S. GF40 4st gas

Can anyone tel me how this carb differs from a carb on a DLE? How does it pump the gas from the tank?

Thanks

TB
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Old 07-15-2013, 06:22 AM
  #64  
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Default RE: O.S. GF40 4st gas


ORIGINAL: MKnutson

The tank in my plane, (Giant super sportster), is right in line with the carb and it's also a fairly small one too, 8oz.
The instructions say to leave fuel in the carb when your done for the day, when I do that it stinks up the plane room in the house. So I run it dry when i'm done now.
Hot restarts can be a little trying at times if hand starting, the electric starter works wonders here!

Mark.
I did a hot start and it started right up with the starter. The only thing that has worked is clamping off the fuel line after running.

TB
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Old 07-19-2013, 06:37 AM
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Default RE: O.S. GF40 4st gas

I wonder if OS will come out with a smaller displacement four stroke. 22cc maybe? That will be nice.
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Old 07-19-2013, 07:19 AM
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I hope they make a 70cc 4 stroke or something that almost matches a 50cc 2 stroke, to fit all the 50cc acro and warbird airframes that are around now.
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Old 07-19-2013, 09:14 AM
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Default RE: O.S. GF40 4st gas


ORIGINAL: WindGap

I wonder if OS will come out with a smaller displacement four stroke. 22cc maybe? That will be nice.
-
I will be also willing to see 30cc-35cc version.
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Old 07-19-2013, 10:35 AM
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Default RE: O.S. GF40 4st gas


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I hope they make a 70cc 4 stroke or something that almost matches a 50cc 2 stroke, to fit all the 50cc acro and warbird airframes that are around now.
And preferably a twin cylinder version..
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Old 07-19-2013, 12:54 PM
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Default RE: O.S. GF40 4st gas


ORIGINAL: AeroFinn


ORIGINAL: SJN

I hope they make a 70cc 4 stroke or something that almost matches a 50cc 2 stroke, to fit all the 50cc acro and warbird airframes that are around now.
And preferably a twin cylinder version..
If a Twin then most likely it will be 80cc, wich will be built based on Gf40.
The same approach is already used by SAITO.
I wish to sneak into OS lab to see what is the next on the table :-)
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Old 07-19-2013, 01:40 PM
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Default RE: O.S. GF40 4st gas

ORIGINAL: WindGap

I wonder if OS will come out with a smaller displacement four stroke. 22cc maybe? That will be nice.
NGH owner said he was planning to make a 22cc 4T engine. You can PM or email him michaelchow2099@hotmail.com


ORIGINAL: SJN

I hope they make a 70cc 4 stroke or something that almost matches a 50cc 2 stroke, to fit all the 50cc acro and warbird airframes that are around now.
there is already a KOLM 65 so your wish should be: I hope they make a cheap 70cc 4T engine

15, 22, 33, 40-4T, 55, 60 I bet the next one is a 110/120cc

Mike.

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Old 07-19-2013, 01:47 PM
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Default RE: O.S. GF40 4st gas

ORIGINAL: AeroFinn


ORIGINAL: SJN

I hope they make a 70cc 4 stroke or something that almost matches a 50cc 2 stroke, to fit all the 50cc acro and warbird airframes that are around now.
And preferably a twin cylinder version..

If its a twin, then make it inline :-)

Boxer engines dont fit well in spitfires and mustangs, and a whole lot of warbirds


And yea, there is the Kolm.......but it is a bit expensive, and there is no muffler with it.
Their 50cc is so much more expensive than the OS 40cc 4 stroke.

Roto and saito make nice large boxer engines.....but cant use those for the reasons above.
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Old 07-19-2013, 04:57 PM
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ORIGINAL: SJN

If its a twin, then make it inline :-)

http://modellmotoren.eu/VT%2085%202R.htm
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Old 07-20-2013, 12:43 AM
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Default RE: O.S. GF40 4st gas

Yea, I have seen that one........but I am a bit picky..... It just looks a bit "home made" to me

I like the clean finish and robustness in the OS,Saito ect. designs.
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Old 07-20-2013, 03:58 AM
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Default RE: O.S. GF40 4st gas

"home made" does not always mean junk
the problem here is the price and availability of spare parts, if you have a dispute with engines maker you won't be able to get parts elsewhere.

"I like the clean finish" so you like NGH engines

Mike.

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Old 07-20-2013, 08:26 AM
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Default RE: O.S. GF40 4st gas

Well, I got that one because the price was right at that moment, and the OS engine was not out.
And the look of it is actualy nice. At the moment it performs well, and im satisfied with it.

But had the os 40cc been out, I would have spent the little extra, and got it for sure.
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