hello everyone,i am new to the hobby. ihave a rascal forty powered by an os 46 la.i was wondering if anyone has anything good to say about the la series.i have 14 landings under my belt and everyone is a dead stick.this engine tends to stall when cut back to an idle.

thank you for your response.

try the engine forum you may get better responses.

to answer your question I can only speak about the .40la engine I have and until it got ran over by a car , the engine ran great.

I have a 40LA in my avistar and it runs great. It will sit there and idle for me all day. Coming in for a landing i can cut the throttle and it will acually sound like the engine died...intill it gets closer to ya. And it provides enough power for me for take off, and maneuvers in the air.

Sorry to hear your not having as much luck.

-Dustin

lioneltamara,
There is nothing wrong with the LA series of motors. From what you are saying I suspect that the low end mixture may be off a bit on your motor. Are you flying at a club? If so see if you can get an experienced pilot to take a look at it and see if they can help get it tuned it.

Ken

Agree fully with the other posts, it's a great little engine in either 40 or 46 size. Runs forever and makes great power on 10%. Sure, it's no 46AX but then it's not trying to be the top of the line sports engine but rather a very honest workhorse that will last forever.

I can't help but comment how fellow club members are always asking me if I've done something to my 40LA, it copes with all but the worst of winds and revs nicely at 12000RPM. They can't believe how good it goes.

Pull the baffle in the muffler, change to 10%nitro (I don't see the point in more), and tune it for peak revs. You will know when you've gone too far as it quickly runs rough, turn it back a few clicks from peak power so as to ensure a safety margin.

If it's dead-sticking all the time either the idle is too low, the engine hasn't fully run in, or you have it way too lean. Better to run it too rich to start with until it's had quite a lot of fuel through it (say a gallon), after that you can lean it right out for power.

There's no reason to post a new thread in the engine forum, plenty of people watch this one, and it's actually valuable to have this subject discussed in the beginner forum.

The LA engines are fine. They're not high powered engines, but properly adjusted, they run fine. Unfortunately, what often happens is that an engine series gets a bad reputation and people use this as an excuse when they don't adjust it correctly. This summer I helped 2 different people sort out engines that were known to be "troublesome" and which others had given up on. In both cases, the root cause was the glow plug. Once I put in a good plug we were able to get them running flawlessly.

If yours is stalling when you throttle back, something is not adjusted correctly. The problem could be:
1) Idle airbleed screw not adjusted right.
2) Wrong or bad glow plug. I like OS #8 for general sport flying.
3) Attempting to idle it too low.
4) Bad fuel.
5) Waiting too long to land, so the fuel is too low in the tank.

You've got to get the engine running well on the ground. Make sure it will idle for 30-45 seconds and then power back up with minimal hesitation. Try doing this with the tank 1/4 full and see what happens. Be sure the high speed needle is not too lean or rich. Don't rely on the "pinch test", it's not accurate. Set the high speed needle to where you think is right. Then get a firm grip on the plane and point the nose straight up. If the engine slows immediately, it's too lean. Lower the nose and set it richer. If the engine speed doesn't change, or gradually slows, it's also too lean. If the engine speeds up a little and then holds this speed (you want to keep it pointed up for at least 5-10 seconds), the needle is just about right. If the engine speeds up significantly, the needle is too rich.

Once you've got the high speed needle set right you can begin working with the air bleed screw. One of the best tips I ever learned for getting the low speed idle mixture close to correct is to start the engine and leave the glow connector attached. Run the engine up to full to clear out the carb and then back to idle. Let it idle for 5-10 seconds and then remove the glow connector. If the engine slows significantly, it's too rich. If the engine slows a little, it's just about right. If the engine speed doesn't change at all, it could be right, but it's possibly too lean. Once it's close to correct, remove the glow connector and let it idle for a good 30 seconds and then bring it quickly up to full throttle. If the engine immediately dies, it's probably too lean. If it stumbles and spits fuel out the muffler, but eventually starts speeding up, it's probably too rich.

And finally, a note about the carb types. The LA series has an air bleed carb for controlling idle mixture. Many other engines have a second low speed needle. The air bleed carbs have a small hole in the front of the carb that lets in a bit of air when the throttle is nearly closed. There is a screw that can be used to control how much of this hole is open. When you turn the screw in the hole is smaller, which lets less air in. This gives you a richer idle mixture. Turning the screw out opens the hole and allows more air in. This gives you a leaner mixture. Some people say air bleed carbs don't work well, but I've always had good luck with them. One of the planes I fly has a Thunder Tiger GP-15 on it. The engine starts with a couple flips, idles perfectly, transitions to full without stumbling, and shuts off when I tell it to. Can't ask for more than this.

Note to anyone else thinking of adding to this post, there's a duplicate in the engine forum: http://www.rcuniverse.com/forum/fb.asp?m=3440470

Lionel,
Chuck is correct. This is a duplicate post. I'm going to lock this thread down as it seems like you are getting great advice in the engine forums. For anybody interested in following this problem you can find that thread here [link]http://www.rcuniverse.com/forum/m_3440470/tm.htm[/link] .

Ken