A long post about my engines. Please read it.
07-06-2003, 11:51 AM
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A long post about my engines. Please read it.
I bought 2 brand new engines couple of months back(OS 46 FX and TT Pro 46) The engines ran great initially and I had no problem at all. My field is very muddy and dirt went into the carburetor of both my engines. As per instructions I removed the back plate and head plate and soaked both the engines in glow fuel and put everything back again. After that the engines ran fine for few days but recently the engines have become a piece of crap. My TT Pro 46 does not give any resistanc while flipping the propellor and no matter what I do(checked for fuel line leaks,glow plug,fuel tank height,clunk position etc.) The engine never runs for more than 2 mins and it is never running stable and always fluctuating speed. My Os46 FX has the exact same problem. I even fixed the good old needle valve leak but to no avail. Fuel is ok because I ran it on another guys engines and it ran fine. Even showed it to some experienced club members and they said that everything seems fine but still couldnt cure the problem. I am thinking of ordering 2 new engines but if their life is also 2 mnths then I will quit as it will cost me alot. I am really frustrated as I have 3 new planes al waiting to be tested but engines are gone. Any advice from anyone here to fix them will be grealy appreciated. Thank you.
07-06-2003, 01:27 PM
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A long post about my engines. Please read it.
Wore out two engines in two months? Wow! Before you drop all that money to buy new ones, make sure the engines are trashed. Look at the crankshaft journal through the carb hole (take the carb off to get a full view). Is the journal scored from injesting mud as you said happened? Look at the piston through the exhaust port. Is it scored and scratched as well? Is it discolored (from lean running or overheating)? When you turn the engine over by hand, do the bearings feel gritty and rough? If these signs exist, maybe you did wipe them out. If you field is that dirty, run an air filter on your engines!! Your engines should run for several years before needing any parts replacement. If you did wear out your piston and cylinder liner, those can be replaced a lot cheaper than a new engine. If everything else is wore out too, you might as well keep these two engines for parts, and get new.
FP
FP
07-06-2003, 01:59 PM
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A long post about my engines. Please read it.
I agree with the about post too. It is a possible that the mud prematurely wore out the engines. I have both of these engine and can attest that they are probably the cream of the crop when it comes to reliablity and ease of use. On the TT engine if the top end pinch is gone then the piston and liner are worn. This would explain the erratic idle too. You did not say if this was showing on the FX engine. If the FX is still showing a pinch and good compression maybe try to get someone with the same engine to swap carbs temporarly to see if that makes a difference. If this does not help then I would just replace the piston and liner on both engines. Preferably with a true ABC liner instead of an ABN. Use the hot breaking method to breakin the new piston and liners on both engines. Good luck.
Sport10
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07-06-2003, 06:26 PM
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A long post about my engines. Please read it.
What is a liner? do you think even a little bit of dirt in carburetor can make such a big difference?
07-06-2003, 07:24 PM
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A long post about my engines. Please read it.
If your engine has ingested MUD it will be damaged...period... no question about it.
Even if it was "a little bit"... What do you call a little bit, by the way? The only things that belong in an engine are air and fuel... everything else is VERY likely to cause minor or major damage.
Take a piece of shiny aluminium and take a piece of VERY fine sandpaper (1000 grit or something like that). Now rub the sandpaper against the aluminium ONCE... What you see is the effect that dirt has in your engine.
Now take into consideration that the "mud" on your field will be a lot coarser than the 1000 grit sandpaper and that the parts in your engine move back and forth like 200 times PER SECOND...
Why do you think car manufacturers put air filters on their engines? And even advise you to replace them every now and then? Because a car is always driving around in the dirt, that's why... One car more than another, but they all do...
If your field is that dusty or muddy, you need an air filter, or you will keep ruining engines...
The reason most people get by without airfilter is that most of the dirt is concentrated near the ground, and not up in the air. So the engine only gets a hard time during take off and landing, which is only a very small percentage of the total run time.
And a second reason is that most fields are pretty clean. People just don't go flying in dusty and muddy conditions.
And a cilinder liner is the hard metal piece in which the piston moves up and down. It is pressed into the aluminium casting which forms the engine block.
Even if it was "a little bit"... What do you call a little bit, by the way? The only things that belong in an engine are air and fuel... everything else is VERY likely to cause minor or major damage.
Take a piece of shiny aluminium and take a piece of VERY fine sandpaper (1000 grit or something like that). Now rub the sandpaper against the aluminium ONCE... What you see is the effect that dirt has in your engine.
Now take into consideration that the "mud" on your field will be a lot coarser than the 1000 grit sandpaper and that the parts in your engine move back and forth like 200 times PER SECOND...
Why do you think car manufacturers put air filters on their engines? And even advise you to replace them every now and then? Because a car is always driving around in the dirt, that's why... One car more than another, but they all do...
If your field is that dusty or muddy, you need an air filter, or you will keep ruining engines...
The reason most people get by without airfilter is that most of the dirt is concentrated near the ground, and not up in the air. So the engine only gets a hard time during take off and landing, which is only a very small percentage of the total run time.
And a second reason is that most fields are pretty clean. People just don't go flying in dusty and muddy conditions.
And a cilinder liner is the hard metal piece in which the piston moves up and down. It is pressed into the aluminium casting which forms the engine block.
07-07-2003, 04:06 AM
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A long post about my engines. Please read it.
The way these ABC/ABN engines are designed the cylinder in which the piston moves in is removable. Therefore you can buy a replacement cylinder or sometime called a liner. When this is done a new piston is also mandiatory too. Most of the time these replacement parts are sold in pairs. Types of liners include: ABC= Aluminum piston, Brass liner that is Chrome plated. ABN= Aluminum piston, Brass liner that is Nickel plated or sometimes called composite. AAC= Aluminum piston, Aluminum bore that is Chrome plated. This type does not have a removable liner. The most desirable is true chrome plating due to the hardness of the plating.
Also, getting trash in the carb will definately make the engine run erratic and cutout. Maybe you should disassemble the carb and inspect for some dirt or debris.
Also, getting trash in the carb will definately make the engine run erratic and cutout. Maybe you should disassemble the carb and inspect for some dirt or debris.
07-08-2003, 05:41 AM
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A long post about my engines. Please read it.
Guys I was finally able to run my os46 fx succesfully. Last night I decided to start the engine at home with no wings attached. What I noticed was that the fuel tank was vibrating horribly(I just had it enclosed in wood and no foam) Next I put some foam and the vibration went away and engine ran smooth. Now I just have to fix my TT Pro 46. The problem with TT is that there is no resistance while flipping and the carb is spitting fuel. Hope I can make it to work.
