How important is the break in procedure?
03-16-2010, 04:44 PM
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How important is the break in procedure?
Particularly for a sport type engine?
I tend to be more methodical in following the break in for expensive 4-strokes than for an OS .46LA. In the former case it’s by the book on an engine test stand. In the latter, it’s run the engine rich on the model on the ground for the first tank, and then keep her rich for the first few flights.
Rarely am I ever trying to squeeze out the last 2% on an engine so I avoid lean runs, which is probably the most damaging.
I tend to be more methodical in following the break in for expensive 4-strokes than for an OS .46LA. In the former case it’s by the book on an engine test stand. In the latter, it’s run the engine rich on the model on the ground for the first tank, and then keep her rich for the first few flights.
Rarely am I ever trying to squeeze out the last 2% on an engine so I avoid lean runs, which is probably the most damaging.
03-16-2010, 04:56 PM
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RE: How important is the break in procedure?
It's probably best to follow the manufacturer's instructions but I will admit that I'm more likely to take a shortcut on a $50 engine than one that cost $200 or more.
03-16-2010, 05:05 PM
#3
RE: How important is the break in procedure?
I don't care what the engine is, I do them all the same - I run a tank through it while adjusting the mixture from rich to slightly lean. Then I leave it slightly rich and get 3 or 4 flights like that.
All my engines run great.
All my engines run great.
03-16-2010, 05:29 PM
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RE: How important is the break in procedure?
I happen to have an OS 46 la. And I'm not very happy with it at the moment
Of course I thought I broke it in properly but its still not right. Going to remove it and go thru everything before next flight. So, what are the symptoms of an improperly broken in engine?
.
Of course I thought I broke it in properly but its still not right. Going to remove it and go thru everything before next flight. So, what are the symptoms of an improperly broken in engine?
.
03-16-2010, 06:03 PM
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RE: How important is the break in procedure?
ORIGINAL: shaggy48
I happen to have an OS 46 la. And I'm not very happy with it at the moment
Of course I thought I broke it in properly but its still not right. Going to remove it and go thru everything before next flight. So, what are the symptoms of an improperly broken in engine?
.
I happen to have an OS 46 la. And I'm not very happy with it at the moment
Of course I thought I broke it in properly but its still not right. Going to remove it and go thru everything before next flight. So, what are the symptoms of an improperly broken in engine?
.
03-16-2010, 06:38 PM
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RE: How important is the break in procedure?
ORIGINAL: jimmyjames213
as long as you didnt run it way to rich or lean you should be ok
as long as you didnt run it way to rich or lean you should be ok
Is too rich harmful or does it just foul the glow plug?
03-16-2010, 09:31 PM
#7
RE: How important is the break in procedure?
I once ran a brand new ABC engine way way way rich for 45 minutes to see what would happen to it. The rod ran in very nicely but the piston was unmarked and still had the same pinch as it had out of the box. From that, the mixture setting I now use starts where the engine is just breaking between a 4 and 2 stroke and then gradually lean it a little at a time over the next couple of tanks to slowly build up heat. Very rich running won't harm the plug in the slightest.
For an LA, or any bushed crank engine, you need a fuel with a high percent of castor and about 20+% total oil for long life. The rest of the engine will appreciate that oil too
.
For an LA, or any bushed crank engine, you need a fuel with a high percent of castor and about 20+% total oil for long life. The rest of the engine will appreciate that oil too
.
03-17-2010, 11:23 AM
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RE: How important is the break in procedure?
Hi!
The only thing to remember with modern ABN engines is to run them slightly rich the first couple of times you fly.
At least I do so...but you could as well forget it and run them flat out! Modern engines can withstand lots of abuse without you notice any faults.
The only important to really avoid is dirt and grit! That means never have the plane engine sitting idleling /running in the pits, on the ground for any length of time. Sucks in lots of particles that way that destroy the engine in a jiffy!
The only thing to remember with modern ABN engines is to run them slightly rich the first couple of times you fly.
At least I do so...but you could as well forget it and run them flat out! Modern engines can withstand lots of abuse without you notice any faults.
The only important to really avoid is dirt and grit! That means never have the plane engine sitting idleling /running in the pits, on the ground for any length of time. Sucks in lots of particles that way that destroy the engine in a jiffy!
03-17-2010, 11:42 AM
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RE: How important is the break in procedure?
I tend to be more methodical in following the break in for expensive 4-strokes than for an OS .46LA. In the former case it’s by the book on an engine test stand. In the latter, it’s run the engine rich on the model on the ground for the first tank, and then keep her rich for the first few flights.
Rarely am I ever trying to squeeze out the last 2% on an engine so I avoid lean runs, which is probably the most damaging.
Rarely am I ever trying to squeeze out the last 2% on an engine so I avoid lean runs, which is probably the most damaging.
PS-don't forget caster and 20% overall oil
03-17-2010, 05:29 PM
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RE: How important is the break in procedure?
ORIGINAL: downunder
I once ran a brand new ABC engine way way way rich for 45 minutes to see what would happen to it. The rod ran in very nicely but the piston was unmarked and still had the same pinch as it had out of the box. From that, the mixture setting I now use starts where the engine is just breaking between a 4 and 2 stroke and then gradually lean it a little at a time over the next couple of tanks to slowly build up heat. Very rich running won't harm the plug in the slightest.
For an LA, or any bushed crank engine, you need a fuel with a high percent of castor and about 20+% total oil for long life. The rest of the engine will appreciate that oil too.
I once ran a brand new ABC engine way way way rich for 45 minutes to see what would happen to it. The rod ran in very nicely but the piston was unmarked and still had the same pinch as it had out of the box. From that, the mixture setting I now use starts where the engine is just breaking between a 4 and 2 stroke and then gradually lean it a little at a time over the next couple of tanks to slowly build up heat. Very rich running won't harm the plug in the slightest.
For an LA, or any bushed crank engine, you need a fuel with a high percent of castor and about 20+% total oil for long life. The rest of the engine will appreciate that oil too
.
You just "got lucky" downunder. There are stories of folks falling out of airplanes without a parachute at over 20k feet of altitude and living, but I don't think I would make a regular practice of it.
Ed Cregger
03-17-2010, 05:31 PM
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RE: How important is the break in procedure?
ORIGINAL: jaka
Hi!
The only thing to remember with modern ABN engines is to run them slightly rich the first couple of times you fly.
At least I do so...but you could as well forget it and run them flat out! Modern engines can withstand lots of abuse without you notice any faults.
The only important to really avoid is dirt and grit! That means never have the plane engine sitting idleling /running in the pits, on the ground for any length of time. Sucks in lots of particles that way that destroy the engine in a jiffy!
Hi!
The only thing to remember with modern ABN engines is to run them slightly rich the first couple of times you fly.
At least I do so...but you could as well forget it and run them flat out! Modern engines can withstand lots of abuse without you notice any faults.
The only important to really avoid is dirt and grit! That means never have the plane engine sitting idleling /running in the pits, on the ground for any length of time. Sucks in lots of particles that way that destroy the engine in a jiffy!
I'm with you, jaka. Slightly rich wonn't hurt a thing, even with ABC engines with an aggressive pinch.
Ed Cregger
03-17-2010, 05:37 PM
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RE: How important is the break in procedure?
G'day shaggy 48. When you say your are not happy with your LA 46 - what problems are you having?
The LA 46 is one of the easiest engines to put into service. As has been said, just run it slightly rich and go and fly once it has a tank or two through it.
The LA series are plain bearing or bushed engines. No ball bearings which is good for simplicity and also for crash damage resistance. They are not quite as powerful as other 46 class engines but are easier to tune and tougher.
The simple "air bleed" carby works well and is not difficult to adjust so long as you remember that the air bleed screw (the one that opens and closes the small hole in the front of the carby body) works in reverse to other low speed adjustments. As you open the hole, you lean the mixture and as you close it , you enriched the mixture. Start with it set about half way. This will be about right but probably a little on the rich side if the one I was playing with yesterday is anything to go by.
Use fuel with some castor oil in it - the more the better for the bushing up to about 20% or even 25 while running in.
It is highly unlikely you have damaged the engine just by running it on the bench.
Back in the dark ages before ABC, ABN, ABx motors like you have (alumnium piston in a Chromed or Nickel coated brass lines), we had engines with scintered cast iron pistons in steel liners. These needed to be run for about an hour in short runs to heat soak the piston and liner to relieve stresses and to get a good fit. ABx engines do not need this treatment and are far easier to run in. Ringed engines (usually a cast iron piston ring on an aluminium piston in various types of liner) still need some heat cycles to get the ring to bed properly into the cylinder wall for a good fit.
Bung it in a trainer or similar, put an 11 x 6 prop on it, feed it some decent fuel (10% nitro, some castor up to 20%) and go flying with it set just lean of where it is four stroking (missing every second rotation). And enjoy.
The one we were flying yesterday was happily hauling a funfly type model around. It did tent to load up (accumulate excess fuel in the crank case and start spluttering) after about 20 seconds at idle and so it probably needs the air bleed opened slightly. To stop this, we just gave the throttle a blip occasionally to clear the fuel out of the crank case to keep it running.
Does any of this make sense?
PS And don't pull it apart unless you really need to. It upsets the fit of things and does not do your engine any good. It is OK to pull the back plate off to check that things are clean inside but really, with a plain bearing engine, there is really no need to do this. After a crash or damage, well, that is a different matter.
The LA 46 is one of the easiest engines to put into service. As has been said, just run it slightly rich and go and fly once it has a tank or two through it.
The LA series are plain bearing or bushed engines. No ball bearings which is good for simplicity and also for crash damage resistance. They are not quite as powerful as other 46 class engines but are easier to tune and tougher.
The simple "air bleed" carby works well and is not difficult to adjust so long as you remember that the air bleed screw (the one that opens and closes the small hole in the front of the carby body) works in reverse to other low speed adjustments. As you open the hole, you lean the mixture and as you close it , you enriched the mixture. Start with it set about half way. This will be about right but probably a little on the rich side if the one I was playing with yesterday is anything to go by.
Use fuel with some castor oil in it - the more the better for the bushing up to about 20% or even 25 while running in.
It is highly unlikely you have damaged the engine just by running it on the bench.
Back in the dark ages before ABC, ABN, ABx motors like you have (alumnium piston in a Chromed or Nickel coated brass lines), we had engines with scintered cast iron pistons in steel liners. These needed to be run for about an hour in short runs to heat soak the piston and liner to relieve stresses and to get a good fit. ABx engines do not need this treatment and are far easier to run in. Ringed engines (usually a cast iron piston ring on an aluminium piston in various types of liner) still need some heat cycles to get the ring to bed properly into the cylinder wall for a good fit.
Bung it in a trainer or similar, put an 11 x 6 prop on it, feed it some decent fuel (10% nitro, some castor up to 20%) and go flying with it set just lean of where it is four stroking (missing every second rotation). And enjoy.
The one we were flying yesterday was happily hauling a funfly type model around. It did tent to load up (accumulate excess fuel in the crank case and start spluttering) after about 20 seconds at idle and so it probably needs the air bleed opened slightly. To stop this, we just gave the throttle a blip occasionally to clear the fuel out of the crank case to keep it running.
Does any of this make sense?
PS And don't pull it apart unless you really need to. It upsets the fit of things and does not do your engine any good. It is OK to pull the back plate off to check that things are clean inside but really, with a plain bearing engine, there is really no need to do this. After a crash or damage, well, that is a different matter.
03-17-2010, 06:16 PM
#13
RE: How important is the break in procedure?
ORIGINAL: NM2K
You just ''got lucky'' downunder.
You just ''got lucky'' downunder.
.
03-17-2010, 11:16 PM
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RE: How important is the break in procedure?
Hi Mike109,
Thanks for all the information on the 46LA. Well I've become a bit concerned for several reasons. So please bear with me while I try to explain what the problem is with the engine. I've had it in a tower trainer for some time now and have put right at 3 quarts and one tank of fuel through it, mostly all flying. Of course I've run it some on the ground to help break it in and tinker with the high speed needle while I invert it, hold it straight up etc. But not a lot of running on the ground.
The fuel I've used until recently has been the 10% from Tower Hobbies. Just recently I bought a gallon of Omega 10%. And have only put 1 tank of that through the engine. This seems to have made the problem worse, but I'm not blaming the fuel, it just seemed to have needed a little more richness when I changed fuel so I may have caused the problem to get worse.
what the engine has always done is it seems to run fine on a full tank. But from about half a tank and below it will try to die. On the tower fuel I could hear it in the air missing or studdering, especially during transitions but it would maybe die every third flight or so. Yes, I'm now very good at dead stick landings. The last time I flew it, (a week ago), it would dead stick almost every time using the Omega fuel. But again only when the tank got low. I've no doubt that if I'd filled up again it would have run fine.
I thought I had solved the problem by tightening the back plate which evidently I'd been flying with loose for some time. But that doesn't seem to have doe the trick after all. Yes I've checked to make sure the fuel line is not sticking in the tank. So now I'm hunting for a fix again.
I didn't mean to imply that I was going to take the engine apart. I'm just going to take it off the plane, check the fuel line, look for leaks check for clogging filter etc. Anything that could be causing the symptoms. I'm open to suggestions here.. Other than take it off and throw it away.
Bottom line, I've never been able to run a full tank of fuel through with this motor without it trying to die, or does die. Usually when I hear if about to die I'll land and refuel and the problem goes away. But every time, I'm just topping off the tank. Looking forward to dead sticking because I've actually run out of fuel! And not because the engine just quits.
Shaggy
Thanks for all the information on the 46LA. Well I've become a bit concerned for several reasons. So please bear with me while I try to explain what the problem is with the engine. I've had it in a tower trainer for some time now and have put right at 3 quarts and one tank of fuel through it, mostly all flying. Of course I've run it some on the ground to help break it in and tinker with the high speed needle while I invert it, hold it straight up etc. But not a lot of running on the ground.
The fuel I've used until recently has been the 10% from Tower Hobbies. Just recently I bought a gallon of Omega 10%. And have only put 1 tank of that through the engine. This seems to have made the problem worse, but I'm not blaming the fuel, it just seemed to have needed a little more richness when I changed fuel so I may have caused the problem to get worse.
what the engine has always done is it seems to run fine on a full tank. But from about half a tank and below it will try to die. On the tower fuel I could hear it in the air missing or studdering, especially during transitions but it would maybe die every third flight or so. Yes, I'm now very good at dead stick landings. The last time I flew it, (a week ago), it would dead stick almost every time using the Omega fuel. But again only when the tank got low. I've no doubt that if I'd filled up again it would have run fine.
I thought I had solved the problem by tightening the back plate which evidently I'd been flying with loose for some time. But that doesn't seem to have doe the trick after all. Yes I've checked to make sure the fuel line is not sticking in the tank. So now I'm hunting for a fix again.
I didn't mean to imply that I was going to take the engine apart. I'm just going to take it off the plane, check the fuel line, look for leaks check for clogging filter etc. Anything that could be causing the symptoms. I'm open to suggestions here.. Other than take it off and throw it away.
Bottom line, I've never been able to run a full tank of fuel through with this motor without it trying to die, or does die. Usually when I hear if about to die I'll land and refuel and the problem goes away. But every time, I'm just topping off the tank. Looking forward to dead sticking because I've actually run out of fuel! And not because the engine just quits.
Shaggy
03-17-2010, 11:50 PM
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RE: How important is the break in procedure?
G'day
I suspect your problem is simply that the engine is tuned a little too lean. As a tank empties, the mixture gets leaner and you then get to a point where the mixture is too lean for the engine to run properly and eventually it stops. I suspect that if you richen it up a bit you will have more luck.
Different fuels will need different tunes too. This is not surprising. It could also be (I don't know the particular trainer you have) that the tank is a little too low and this would make things worse.
Have you adjusted the air bleed? If so, put it back so it is in the middle of its adjustment so the hole is half open (or half closed if you prefer). This will usually make the engine a little rich at idle but it should run OK like this though it will probably load up a bit. Also, when you are adjusting the air bleed, get the engine running at absolutely peak revs (as lean as possible without stalling) then adjust the airbleed and once it is right, re-set the needle valve so the engine is slightly lean from four stroking. You may be able to go leaner in time but you should never tune the engine fully lean on the ground and then fly it at this setting. Always set it sightly rich if you want it to last. Lean = Heat = Death if done for too long.
Then start the engine and tune it so it starts to four stroke (richer) then turn the needle in so it just stops four stroking (runs smoothly with only an occasional miss) amd fly it like this and see what happens. It may sound a little rough at the start of the flight but in a trainer who cares and it should improve through the flight.
If this still causes dead sticks, then it sounds like a more fundamental fuel problem. A leak or something like that.
You can also improve the leaning problem as the tank empties by modifying the tank to a Uniflow arrangement. This needs a second clunk. Instead of having the tank vent simply bent to the top of the tank, you put a second clunk on it like the fuel pickup but you make it slightly shorter and hold the two tubes together gently with heatshrink or cable ties so they follow each other round the tank. If you do this, you also need a third breather at the top of the tank which you open when you are filling the tank and then seal with a plug when the tank is in use. If you do a search for Uniflow you will find better instructions on setting up a uniflow tank. It really works and minimises the leaning as the tank empties problem.
All the best
Mike in Oz
I suspect your problem is simply that the engine is tuned a little too lean. As a tank empties, the mixture gets leaner and you then get to a point where the mixture is too lean for the engine to run properly and eventually it stops. I suspect that if you richen it up a bit you will have more luck.
Different fuels will need different tunes too. This is not surprising. It could also be (I don't know the particular trainer you have) that the tank is a little too low and this would make things worse.
Have you adjusted the air bleed? If so, put it back so it is in the middle of its adjustment so the hole is half open (or half closed if you prefer). This will usually make the engine a little rich at idle but it should run OK like this though it will probably load up a bit. Also, when you are adjusting the air bleed, get the engine running at absolutely peak revs (as lean as possible without stalling) then adjust the airbleed and once it is right, re-set the needle valve so the engine is slightly lean from four stroking. You may be able to go leaner in time but you should never tune the engine fully lean on the ground and then fly it at this setting. Always set it sightly rich if you want it to last. Lean = Heat = Death if done for too long.
Then start the engine and tune it so it starts to four stroke (richer) then turn the needle in so it just stops four stroking (runs smoothly with only an occasional miss) amd fly it like this and see what happens. It may sound a little rough at the start of the flight but in a trainer who cares and it should improve through the flight.
If this still causes dead sticks, then it sounds like a more fundamental fuel problem. A leak or something like that.
You can also improve the leaning problem as the tank empties by modifying the tank to a Uniflow arrangement. This needs a second clunk. Instead of having the tank vent simply bent to the top of the tank, you put a second clunk on it like the fuel pickup but you make it slightly shorter and hold the two tubes together gently with heatshrink or cable ties so they follow each other round the tank. If you do this, you also need a third breather at the top of the tank which you open when you are filling the tank and then seal with a plug when the tank is in use. If you do a search for Uniflow you will find better instructions on setting up a uniflow tank. It really works and minimises the leaning as the tank empties problem.
All the best
Mike in Oz
03-18-2010, 02:58 AM
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RE: How important is the break in procedure?
ORIGINAL: downunder
Well I don't know Ed but maybe I just got lucky with a Bluebird 28 AAC, a Norvel 40, Norvel 25 and an OS 46VF that I treated the same way after my experiment .
ORIGINAL: NM2K
You just ''got lucky'' downunder.
You just ''got lucky'' downunder.
.
03-18-2010, 03:10 AM
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RE: How important is the break in procedure?
Hi shaggy I would stick to the castor based fuel and maybe try a new plug and like Mike says maybe richen the beast up a bit and even replace all the fuel lines if things dont improve. Cheers the pope
03-18-2010, 03:22 AM
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RE: How important is the break in procedure?
ORIGINAL: downunder
Well I don't know Ed but maybe I just got lucky with a Bluebird 28 AAC, a Norvel 40, Norvel 25 and an OS 46VF that I treated the same way after my experiment .
ORIGINAL: NM2K
You just ''got lucky'' downunder.
You just ''got lucky'' downunder.
.
I'm not saying that you are wrong, downunder. In fact, what I AM saying is that there are too many variables to account for in order to apply a general rule of thumb. I, for one, was referring to engines with a good bit of taper and a standard true ABC setup. The OS you mentioned is an ABN engine. Most of them don't have any discernible nip at TDC. At least my 10cc VF didn't have any nip at all. I've never handled the 7.5cc VF. The Bluebird 28 is AAC and NOT ABC, so why is that in the group? I'm not familiar with the Norvel engines and their metallurgy.
Maybe I missed your point?
Ed Cregger
03-18-2010, 08:15 AM
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RE: How important is the break in procedure?
Mike
The plane is the Tower Trainer 40 and no I have not touched the air bleed because I didn't think it was necessary. Now however I think I'm going to have to. I hope the tank isn't too low, that would be a bother to change.
I will tinker with the engine tomorrow following your advice. And if the weather holds I'll fly it and see if it improves. Also, I'm thinking that if I tune it starting from a mostly empty tank (i.e. already lean condition so to speak) Then fill up and fly without changing the settings. The engine should actually richen out at the beginning of the flight (because I just filled the tank) and then it will get back to lean again as the tank empties but hopefully not so lean it will die like before. This would be the opposite of what I'd been doing and if you're right it was getting too lean around half tank and below. OK that all makes sense at least in my head but may not have come out quite right, but I hope enough.
Gotta tell you though I really thought I had it quite rich already. But most likely my idea of what rich sounds like is off.
Oh yeah. Pope. I had not thought of changing the plug. Thanks, worth a try too. I will let you all know how it goes.
Shaggy
The plane is the Tower Trainer 40 and no I have not touched the air bleed because I didn't think it was necessary. Now however I think I'm going to have to. I hope the tank isn't too low, that would be a bother to change.
I will tinker with the engine tomorrow following your advice. And if the weather holds I'll fly it and see if it improves. Also, I'm thinking that if I tune it starting from a mostly empty tank (i.e. already lean condition so to speak) Then fill up and fly without changing the settings. The engine should actually richen out at the beginning of the flight (because I just filled the tank) and then it will get back to lean again as the tank empties but hopefully not so lean it will die like before. This would be the opposite of what I'd been doing and if you're right it was getting too lean around half tank and below. OK that all makes sense at least in my head but may not have come out quite right, but I hope enough.
Gotta tell you though I really thought I had it quite rich already. But most likely my idea of what rich sounds like is off.
Oh yeah. Pope. I had not thought of changing the plug. Thanks, worth a try too. I will let you all know how it goes.
Shaggy
03-18-2010, 08:20 AM
#20
RE: How important is the break in procedure?
The amount of change between a full and almost empty tank should have VERY little difference in mixture change. You are more likely to see a change when the nose is pointed straight up and the fuel has to be drawn against gravity.
03-18-2010, 09:38 AM
#21
RE: How important is the break in procedure?
This is a toss up situation, imo. The easiest thing to do is the advice to replace all fuel lines. That would be the vent line and short piece from the needle valve to the carb. I've had problems in both of those places.
The half of a tank point is where a fuel draw problem or overheating could occur. I don't know enough about the 46LA carb to guess about fuel draw. Swapping carbs would be a good idea if possible.
The half of a tank point is where a fuel draw problem or overheating could occur. I don't know enough about the 46LA carb to guess about fuel draw. Swapping carbs would be a good idea if possible.
03-18-2010, 10:28 AM
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RE: How important is the break in procedure?
I think you should take a simple approach to this-FOLLOW the simple rules. Adjust the tank height, be SURE your plumbing is correct (fuel delivery) take your tank out and pressure check it if need be. Be sure your vent line and pressure lines are correct. Put in a new glow plug, #8 if your still using the one that you broke the engine in with. Fill the tank 3/4 full, set needles per spec-do a pinch test if you can't tell rich from lean. Empty tank then put maybe an 1/4 tank back in and check again-do a pinch test at high and low speed. I'll bet if you do this you solve the problem-It is a fuel delivery issue.
03-18-2010, 10:58 AM
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RE: How important is the break in procedure?
Hi!
To me it sounds as if you have some tank problems. So check the tank.No air bubbles should be seen in the fuellines.
If you see air bubbles you know something is wrong. It's also imperative that you mount the tank according to "the tank rule"...I hope you know what that means!
You should use a 240cc (8oz) tank. And I recommend using the "Uni-flow" system with two clunks (one of fuel to the carb and the other for pressure from the silencer) as this system gives a more even fuel delivery than a normal one-clunk line tank.
I also recommend using a 11x6 or 12x4 prop (RAM or APC). 10x6 is to small prop for a slow rewing OS LA .46 engine in a high winged trainer .
The idle needle on the carb should be half open or slightly more...it's not that critical. Once you give full power the engine should answer directly without hesitation, roaring to full rpm. That's the goal to aim for, and that's easy to achieve with the OS LA series of engines.
To me it sounds as if you have some tank problems. So check the tank.No air bubbles should be seen in the fuellines.
If you see air bubbles you know something is wrong. It's also imperative that you mount the tank according to "the tank rule"...I hope you know what that means!
You should use a 240cc (8oz) tank. And I recommend using the "Uni-flow" system with two clunks (one of fuel to the carb and the other for pressure from the silencer) as this system gives a more even fuel delivery than a normal one-clunk line tank.
I also recommend using a 11x6 or 12x4 prop (RAM or APC). 10x6 is to small prop for a slow rewing OS LA .46 engine in a high winged trainer .
The idle needle on the carb should be half open or slightly more...it's not that critical. Once you give full power the engine should answer directly without hesitation, roaring to full rpm. That's the goal to aim for, and that's easy to achieve with the OS LA series of engines.
03-20-2010, 01:41 PM
#24
Member
My Feedback: (3)
RE: How important is the break in procedure?
I had a Evolution engine that acted the same way. After alot of bad words and a gallon of fuel it ran great! I had a bad jug of fuel. When I switched fuel it ran fine. I noticed you switched brands and still had the problem and it was worse. Different fuels require retuning. I changed fuels and retuned and found a small hole in one of the fuel lines (they tend to split at times). I fxed the fuel line, checked the tank and lines for leaks, changed glow plugs, put new 'O' rings in the carb and finally got it to run right. Sometimes they also require patience. This engine starts with a couple flips and runs great. It did act up once toward the end of a jug of fuel. When you empty your tank back into the jug you deposit water that was ingested through the carb that was in the air that gets into your tank through the vent line. It can collect in the jug and cause the engine to run poorly.
Let us know what you come up with.
Let us know what you come up with.