Anyone had any problems with this enginge had enough dead sticks terying to find out what to do think maybe have to adjust low end on carb any suggestions?

I've had one for about 2 years. No problems at all. Only deadstick is when I run it out of fuel.

Mine came from the factory rich on the low end.
Does yours die when you try to throttle up from idle?
It takes a flat blade jewelers screwdriver to adjust the idle.
Mike

knightmagic,

This may be a long post so bear with me.

It's sounds as though you may be lean. The low speed needle does not adjust the idle, you transmitter does that. It only adjusts the mixture. A rich low speed will make the engine blubber and respond slowly to the throttle and it may deadstick, especially if idling for several seconds, like on a down line in the air or just plain old idling on the ground. A lean mixture will allow the engine to respond quickly but will deadstick if the throttle is opened quickly but may idle forever on the ground.

I am assuming by your post that you have checked for air leaks going from the tank to the high speed needle and from the high speed needle to the carb and that your fuel is fresh. If you have air leaks between the high speed needle valve you will see bubbles in the line from the tank all the way to the carb. If the line between the high speed valve is leaking you will have bubbles between the needle and the carb only. The little "O" ring on the high speed needle will also cause leaks. Any leak will make it difficult to tune.

I also assume you are using the proper sized prop. Anything else will lug this engine and cause it to overheat and no amount of richening will help and the glow plug is good

These engines are usually rock solid. I have had more than my fair share of them and usually sold them with the plane. I can name several that are still flying after setting all winter.

If you need it, here is the manual http://www.osengines.com/manuals/46ax-manual.pdf

Having a tach handy will greatly help, but you can do this by ear. This will take about 10 - 15 minutes to do and if everything else is as it should be you will have a powerful engine that is rock solid

To tune this engine, lets get it back to the factory settings on both needles. Turn the High speed needle until it seats (Clockwise) and then back it out (counterclockwise) 1 1/2 to 2 turns. Now take the low speed needle and seat it (clockwise) and back it out (counterclockwise) 3/4 turn. Be sure not to seat the needles tightly, just seat them until you feel pressure.

Now start the engine and leave the glow driver on. Let it warm up for at least 30 seconds. Make sure the plane is strapped down tightly or is being held firmly. Now go to full throttle, the engine will probably stumble and blubber but that's OK right now, it's rich. Once at full throttle start turning the high speed needle clockwise (leaning it) until the rpm starts to pick up, When first starting this, turn the needle 1/4 turn and wait a few seconds for the engine to clear. Keep doing this until the RPM does not get any higher, once you get to that point turn the needle counterclockwise to rich it so that it looses about 300 rpm. Back off to about half throttle and remove the glow driver, now repeat the high speed needle procedure. Once you have the high speed set, go ahead and lets work on the low speed needle.

Bring the engine to idle and let it sit for about 10 seconds. Now quickly move the throttle to no more than 1/2 throttle, 1/3 throttle is usually pretty good, the engine should respond slowly and blubber and maybe spit fuel out the muffler, that's OK, it's rich. Bring the engine back to idle and stop it. Now turn the low speed needle 1/8 of a turn clockwise (leaning it), no more than 1/8 turn please and restart the engine. Run it up to full throttle and hold it there for a few seconds to clear it out and bring it back to idle and wait 10 seconds, now quickly bring it up to 1/3 throttle. If it is still spitting fuel and slow to respond stop the engine and turn the low speed needle clockwise 1/8 turn again. Restart the engine and repeat the procedure for the low speed needle. Make sure that when you go to adjust the low speed needle you do it with the engine off as you will be very close to the prop.

Keep repeating the low speed sequence until the engine responds instantly up to 1/3 throttle. Once you have that back the low speed needle out 1/16th of a turn (richen it) , then take the engine to full throttle and back to idle. Wait 10 seconds and go to full throttle again quickly. The engine should now be responding instantly. If this is an new engine leave the low speed a little rich for about a gallon. If this engine is already broken in then do not worry about backing the low speed needle out the 1/16th turn.

The reason I am having you go to no more than 1/3rd throttle is because the low speed needle is in effect up to half throttle and then it transitions to the high speed needle.

Hope this helps...

By the way, this will work for most any OS 2-stroke engine...

I always warn people to leave the factory mixture setting alone on OS engines. Usually it's close enough, and I set the idle with th EPA (end point adjustments) on the throttle servo. Anyway I don't spend a lot of time idiling, since I'm usually flying inverted making low passes over the runway. Also, I use the trim to shut it off on my VG400. On Futaba computer radiios, you can put the idle on a switch (Throttle Down and Idle Cut).

You shouldn't even TO until you can get your engine to run reliably on the ground. I'd say at least two tanks of fuel should do it. On a new engine, for your first TO, you should have the needle valve set to the point where the engine just begins to two stroke. On each subsequent flight, you can turn it in a click or two. However, don't run a Max engine too lean. The optimum point is 15-30 degrees off of maximum RPM (leanest point).

Ciao,

Eagle Al

Bubba, I have a word of gratitude and a question. First, the thanks. I used your suggestions to set the high speed adjustment on my OS .46 AX this afternoon, and it works perfectly. Now I need to set the low speed idle. At idle, the engine seems to run fine, but after about 30 - 45 seconds it shuts down. My problem is that I cannot find the throttle control adjustment located anywhere in the materials which the manufacturer supplied. I see a screw which is located just behind the carb. Is that it? If so, how in the world do you get a screwdriver on it to adjust. It sits between the carb and the cylinder head. Any help you can give would be appreciated. Thanks.

Michael,

The screw you are talking about is mainly the stop screw for the throttle barrel inside the carb. There usually is no need to adjust it.

I usually hate to answer a question with a question but I have to in this case.

You mentioned it will idle abot 30 seconds then die. Does it just shut off or does it spit and die.

If it just shuts off it's most likely too lean. If it's spits and sputters then dies it's a little to rich.

The low speed mixture screw/low speed idle screw is located inside the arm where your throttle linkage/clevis is connected to. You will need a small jewlers screwdriver to get to it. On page 10 of the manual you will see a diagram that explains throttle position. There are 2 lines, 1 for 1/4 throttle and 1 for 3/4 throttle. Thise 2 lines are pointing right where the screw is. It's easy to miss because it is actually inside the arm. That is the screw I was saying about making only 1/8 to 1/16 turns on.

Just follow my procedures. Here they are again for the low speed needle just to make it easier for you

BTW...Page 15 of the manual shows the screw in the carb breakdown

http://www.osengines.com/manuals/46ax-manual.pdf

Bring the engine to idle and let it sit for about 10 seconds. Now quickly move the throttle to no more than 1/2 throttle, 1/3 throttle is usually pretty good, the engine should respond slowly and blubber and maybe spit fuel out the muffler, that's OK, it's rich. Bring the engine back to idle and stop it. Now turn the low speed needle 1/8 of a turn clockwise (leaning it), no more than 1/8 turn please and restart the engine. Run it up to full throttle and hold it there for a few seconds to clear it out and bring it back to idle and wait 10 seconds, now quickly bring it up to 1/3 throttle. If it is still spitting fuel and slow to respond stop the engine and turn the low speed needle clockwise 1/8 turn again. Restart the engine and repeat the procedure for the low speed needle. Make sure that when you go to adjust the low speed needle you do it with the engine off as you will be very close to the prop.

Keep repeating the low speed sequence until the engine responds instantly up to 1/3 throttle. Once you have that back the low speed needle out 1/16th of a turn (richen it) , then take the engine to full throttle and back to idle. Wait 10 seconds and go to full throttle again quickly. The engine should now be responding instantly. If this is an new engine leave the low speed a little rich for about a gallon. If this engine is already broken in then do not worry about backing the low speed needle out the 1/16th turn.

The reason I am having you go to no more than 1/3rd throttle is because the low speed needle is in effect up to half throttle and then it transitions to the high speed needle.

Wow, Bubba. I came home from dinner tonight and set the low speed adjustment. Now the engine seems to be running perfectly. I can go straight from idle to full throttle and back with no sputtering or hesitation at all. I am new to this hobby, but I take it that is what you are looking for. The thing is really screaming at full throttle. I cannot imagine using full throttle on my trainer (a Sig Kadet LT-40) very often. Also, I don't have my electric starter yet. It will coming this week. But it only takes one or two flips with the chicken stick to fire off the engine. My main reason for wanting the electric starter is to keep my hands as far away from a spinning propeller as possible. Yes, you can call me a coward, but I am very attached to all ten of my fingers. LOL! Once again, thanks. I have one final question, but I am going to post that in a new thread.

Very cool Mike. Glad it helped out

Mike,

I forgot to ask, What prop are you using on it.

The LT-40 will fly best, in my opinion on a 11X5, not to fast and lots of pulling power with the OS46AX. I personally use APC props but most others work just fine mainly Zinger wood props or Master Airscrew (MAS)