engine causing grief!!
 

i have a super tiger 55 ringed engine thats not even a year old and hasn't seen much flying but it suffered a pretty bad crash.....nothing was broken as we could see, we even took it apart and everything seemed ok. the probelm i'm having is that i started it a day ago and it ran lean so i adjusted it a couple clicks at a time and tryed tuning it with the pinch method and i must have turned it 10 clicks or so and there was no difference. so i left it running wide open for a couple minutes and the second i adjusted it one click more it almost went to four stroke it was that rich. when i leaned it a click it ran ways too lean again. so i'm wondering why it would changed that much just at that one point. its impossible to tune properly because of that. i stopped and started it again its doing the same thing. i pulled the carb of and the barrel that fits in the crankcase has a very obvious scuff mark that must have happened when the plane crashed and the carb twisted. i figuered the o-ring should seal that off but now i'm not sure. so if anyone has any ideas it would be great.

RE: engine causing grief!!
 

Remove the carb and muffler.

First inspect the muffler pressure fitting and make sure it is clear.

Insert a small hex key to clear it.

Next check the muffler nipples as well, you may have debris in there.

Pull out and check the needle valves and make sure that you have not put "rings" into the smoothly tapered seats.

Clean everything.

Once done, put a piece of new and clean fuel tubing on the carb inlet nipple and blow as you move the throttle open and close.

With it fully open you should get a very pronounced "HISS" out of the carb as you do so.
When you fully close the throttle, you should NOT be able to blow into the tubing.

Turn the HS needle in gently. You should be able to reach the point where you CANNOT blow into the carb even with the throttle fully open.

Turn it back out, and check to make sure that the amount of air changes as you turn it out.

RE: engine causing grief!!
 

it's getting air leaks from somewhere.
Or there's debris in the needle valve's jets or nozzle
You can try cleaning it out using a little guitar string or a single strand of wire.

I had an engine that was doing that. i actaully saw fuel coming from the LSN.
So I put ca in it..lol it'll run good for 10-15 mins...but at least i knew that was
the source of the engine's eratic behaviors.

Also makesure the o-ring on the needle is still good and not dried or damage.
If you soak the carb without removing that little o ring on the needle..it might had damaged it.

To isolate the problem of posisable leaks coming from the throat, you can tried JBwelding it.
Double up on the Oring or do both.

RE: engine causing grief!!
 

One way to clean out the needle area is to take the needle out then pump fuel into your system via the fuel fitting. The fuel should eventually come out of the needle valve area and flush it out. Good luck.

RE: engine causing grief!!
 

On the SuperTigre, the outlet for the main needle must spray directly down the throat of the carb. If it is rotated due to the crash, one nut unlocks it, and you can adjust it. That makes a difference in how they run.

RE: engine causing grief!!
 

thanks guys, i'll check all that stuff out

RE: engine causing grief!!
 

I don't know if you checked your tank as well, but along with checking for junk in the carb (my first guess), also check to make sure the clunk isn't stuck in your tank, or you don't have a hole in a fuel line inside or outside the tank. When the engine is running, do you see air bubbles in the line?

Also, some engines have issues with the o-rings on the high and low speed needles getting hard and/or shrinking. A bit of fuel tubing over the high speed needle to help seal it will often help.

RE: engine causing grief!!
 

Sorry to interrupt this post, but I don't want to start a new thread. I'm fed up with my tower .46. Can I put the tower muffler on my o.s. 40 la for more power?

RE: engine causing grief!!
 

Maybe, I'm not sure if the LA has the same bolt pattern. I know the OS .46AX and FX have the same pattern as the Tower .46 (and the Thunder Tiger .46 and some others as well), but I'm not sure about the LA. If you look on the OS engines website or tower, you might be able to look up the bolt spacing to see.

As for adding power, it will add a little, but it's not going to turn the LA into something as powerful as the Tower .46, the Thunder Tiger, or the OS AX.

RE: engine causing grief!!
 

If the bolt holes line up, yes, but it will be a modest increase.

I've not seen any posts from you about trouble with your .46, since you were messing with the LS needle. What trouble are you having with it, it is a much more powerful engine than that LA. It would be worth your time to troubleshoot it, rather than junking it.

What's it doing (or not doing)? Maybe we can help! It's important when troubleshooting that one thing is tried at a time, so as to not create more troubles than you're fixing.

J

RE: engine causing grief!!
 

Okay, here it goes. The last time I flew, it was doing OKAY. I did have one or two dead sticks, so I turned it out a few clicks. Well, seemed to solve the problem. However, I knew that my low speed needed to be tuned, but I figured I'd leave it be until I went flying again. After some confusion as to whether I should turn the low speed in or out, since it's different for aid bleeds[ countclock to lean]and the other kind (forget what it's called, but you know what I mean. I'm still not sure,") I went to the field to try to get a clean advance. Well, first I wanted to make sure my high speed was correct. So, I started all over. That is, open it up 2.5 times and starter her up. Began to increase, but there wasn't really a terrible increase in RPM. So, I did the pinch test, and , out of frustration, left it when there was an increase in RPM, though I think it was too much. In any event, now the engine would barely go to full throttle. It took a while. So, I turned the low speed in, as someone had told me, but there was no difference. The problem became worse, actually, but I wanted to fly and by this time I was getting pissed. So, I got up in the air, throttled down for some touch and goes, and throttled back up, but it was terrible. What terrible sputtering and coughing. So, too rich, right?!!? Well, okay. Now I'm about to bring her down when my exhaust note changes! What the hell is going on here!? I bring her down safely. My muffler screw came loose and the muffler was just about to come apart. Well, that's my problem, I think. So, I tighten it up the best I can. I start her back up but now the damn thing will hardly advance at all. It's completely 4 stroke. It died, and I was unable to get it going again, so left for home.

P.S. I tried to turn the low speed out, but no difference. When I get home, I am going to try all of the above suggestions. Any help would be greatly appreciated, as I don't want to go back to that lackluster o.s 40 la.

RE: engine causing grief!!
 

Don't give up on it, it is a wonderful engine.

Make sure that you have no fuel system issues and that there is nothing obstructing the pressure nipple.

Check the entire fuel system to be sure that you do not have undo restrictions on it.

e.g. with the tank bone dry, hook up a clean tube to the pressure tube, using a short piece of brass pipe... disconnect the fuel line at the high speed needle. BLOW into the pressure tube side, air should FREELY exit the carb side.

Note that overly long lines will cause increased pressure ( or require more vacuum on the carb ) which fouls up the carb settings.

Once done, set the engine needles to their defaults and start over tuning.

The low and high end should start out rich.

Lean out the high end with the engine at full throttle, until it starts to speed up, out of 4 stroke range.

Bring it to idle and check the idle.

Try to get the engine to idle consistently without slowing down over time.

Once you have this, richen it up an additional 1/8 turn but no more.

Then go back to the HS and adjust for highest RPM's then back off from that about 1/8 to 1/4 turn.

Finally double check transition and do pinch tests.

The T.H. engine does not come into it's own until you have run about a gallon through it.

Prior to this you'll find it a bit touch vis-a-vis tuning...

RE: engine causing grief!!
 

Thanks much. Is the .46 an air bleed engine?

RE: engine causing grief!!
 

The Tower .46 is NOT an air bleed engine, it is a dual needle ABC engine which is FAR more powerful than the .46LA.

The .46LA ( and all of the LA's ) are air bleed.

Someone here once said...

"The O.S. .46 LA engine is the BEST .32 engine I've ever owned! ".

He had it right, it is a great .32 engine... in terms of power.

RE: engine causing grief!!
 

Okay, so the low-speed needle is turned IN, correct? Man, I hope I didn't fry this thing. At one point, when I was leaning, I did the pinch test and it quit. When I turned the prop over, smoke came from the muffler . [:'(]

RE: engine causing grief!!
 

On the Tower, turning the LS needle IN leans it out.

Smoke merely means that the head and/or muffler is hot and fuel was on/in it.

As long as the engine turns over you did not "fry" it.

I've seized a T.H. engine because it was both new, and I had it far too lean.

I thought it was toast, as I could not turn it over at the field after that.

By the time I got home I had no problems though...

I richened it, and I've been flying it on a Bobcat ever since... awesome power...

It is better to start a bit rich and work towards leaning.

Working from the lean side can be frustrating as your engine never seems to want to run... so err on the side of having it rich.

At worst set the engine to it's default settings.

To do so, remember you want to OPEN the LS several turns...

Then with the throttle FULLY closed, ( engine cut off, closed! ) turn the LS needle IN, ( clockwise ) until it "touches" the stop. DO NOT force it, when you feel a bit of resistance STOP.

Now turn the LS needle OUT to the default number of turns ( I forgot what it is, look in the manual, but I believe it is 1 1/2 or 1 3/4 ).

Do the same for the HS needle ( although the throttle setting doesn't matter at all for the HS ).

The try to start it. If you can get it to turn over and give you any type of idle, start turning it.

RE: engine causing grief!!
 

You can remove the baffling from the LA's muffuler if noise is not an issue. It'll bascailly do that same as
the TH muffuler. That's why TH muffulers are big.. dapmen the noise without a baffling.
That muffuler is just as big as my .60 size engine.lol
Or get a mac pipe:D

Here's how I solved the problems people say they where having with TH .46.
I read and read about it and stayed away from it for years...but i also read that it was a power house:D
So I got 2. I think you save $10 or get extra glow plugs.lol

Both of mine runs perfect.

I took the fuel system apart sort of..before even starting the engines. I mean, there's not much..so what in the world can cuase all those headaches.[8D]
I put sealent of the backplates of all my engines right out of the box as a habit anywho.

Bascailly there's burrs from the chrome plating of the fuel tubing barbs....cuasing eratic fuel flow.
So i got a crazy notion of de burring all of the barbs.

RE: engine causing grief!!
 

Okay, once I get home from work, I'm going to try to get this right. I'll let you know what happens! Thanks!

RE: engine causing grief!!
 

Yesssssssssssss. It was all about the low speed, baby! It was wayyyyyyyyy too rich. It was out about three times. Now it's out 1.5 and the thing is wonderful! Thanks, guys!

RE: engine causing grief!!
 

No problem, glad you got it sorted out.

You'll love that engine.

Now that it is tuned, you'll merely adjust the high end a click or two depending upon the weather.

RE: engine causing grief!!
 

How do I seal this muffler. It's not coming off at the engine port. The cyclinder is coming loose, which caused three dead sticks today.

RE: engine causing grief!!
 

You have a couple of choices...

I've tried JB Weld but it hasn't held for me.

What I ended up doing was putting RTV sealant along the rim.

Then putting the whole thing together, paying particular attention to screw that long bolt as tight as I could w/o stripping it, BEFORE putting on the nut.

Then I put loctite on the nut and put that on with a nut driver, and finally a second nut to act as tight as I can against that.

( this was suggested by someone at my field and it's worked GREAT ).

You could also drill a hole at the joint, then tap it for a small screw and put the screw in to prevent rotation and also to eliminate any potential loss of the rear part of the muffler.

BTW: Richen it just a tad. My T.H. engine will run with the muffler back off!

Just noisy as anything...

It may be sluggish, but it should not deadstick...

This happened to me with an inverted mount on an Ultimate ( glides like a brick! )... which I brought back after an additional trip around the airfield.

RE: engine causing grief!!
 

Okay, I will turn it out a bit, but it's still a little slugish to full throttle. Lean the low -speed out a bit?

RE: engine causing grief!!
 

Your thread got intercepted and is over the hill concerning topic.

If you have a ST 55, you have a rare jewel. There were .56s at one time but a .55 is definitely over a year old. I don't remember one since my first ST back around 1961. [8D]

Clean it up. Sounds like a dirty carb. A small foreign object inside the NV area can be a real torment unless you take the carb apart and wash throughly in alcohol.

RE: engine causing grief!!
 

No, it sounds like you had it right the first time...

Put it back to how you had it.

it could well be that because the engine is new, it is not tolerating the lack of muffler pressure, or that there is just enough restriction on you fuel lines that prevents the carb from being able to pull in fuel with normal air pressure...

Also your elevation could come into play... I fly at about 200' above sea level.