Maybe somebody can help me..... I have a tiger trainer .60 - great tiger .61 on it swinging a 10x 7.5 master airscrew. Both lines are new, carb is seated correctly, cap on tank is tight.

If i put a finger over the carb inlet and advance the prop to prime, if the plane is tilted to the tail down, the fuel in the line runs back to the tank before i can fire it up.

Also when the engine is running, and i pick up the plane to chech all flight attitudes, it bogs when held nose down, and leans out ( when fuel runs back in tank) and dies. Pressure line from muffler is ok. What the hell can be the problem ?????????????

Steve,

Sounds like you could have any number of problems. The first thing I would do: change the prop to an 11x7 or 11x7.5 or even a 11x8. I think a 10" prop is too small for a .61 size motor.

Secondly, check your carb and pressure lines from your tank, and also the clunk line....sounds like you may be sucking air somewhere. Make sure that after you reassemble it the tank cap is tight.

I am not too familiar with that motor, however, after you've verified the lines are not leaking air, start from the MFG high and low end settings for the motor and go from there.

Let us know what you find or if you have any more problems. Good luck!

Gary

Steve, Welcome to the forum. These things can be frustrating at times, though you do have help at your finger tips here on the forum. I am sure some others will chime in........... This just happened to me last week. My engine was acting like it was out of fuel, leaning out and dying. (I also noticed bubbles in the line). I had not noticed my wing mounted LG was bent back from one of my "exciting landings"!!! :rolleyes: In trying to taxi out the next time the plane also was tipping over forward. Most likely the rough landing caused the air bubbles problem. The line with the clunk got stuck in a "U" shape and the clunk was stuck at the FRONT of the tank!!!! Not good!! :D I didn't even have to take the wing off....just held the plane nose up and rapped on the sides of my fuse and it became un-stuck. Good luck and Happy Landings.... lownslo.....

Bob

um.... er.... okay it is an 11 x 7.5 prop.... geeze, a guy could loose an eye in here. The prop is not the problem, but the clunk might need a good looking it. Is it normal for the fuel to run back into the tank from the carb after the engine is stopped? okay, lets go over the procedure once agian.

1. I close the carb inlet and rotate the prop to get fuel up the line and into the carb (why? there is no fuel in the line yet)

2. If i get it started and running (it is already broken in, peaked,backed off a 1/4 to 1/2 turn and runs like a dream)

3. if i pick the plane up to check all attitudes (nose up,down,etc) the plane will lean out and die (no fuel in line) if i put nose up.

4. have checked all lines and replaced twice. (clunk is next to go)

next???????????

Steve, I have been in r/c a year, and control line YEARS ago. MY experience is limited and like in my other post, I can only relate what I have experienced. First of all lets talk about the prop. It may not have anything to do with the fuel problem but like the other guys said, the 10X7.5 is too small for that engine and you won't get the full potential power from your engine. OK....here is the deal. My trainer did the same thing. I would prime with my finger over the carb, fuel would come up....... then fuel would run back.:rolleyes: It seemed worse if I tried to restart with a half tankfull. MOST of the time I could just hold the starter on and after a couple seconds it would pull the fuel back up and start. (are you useing an electric starter?) IF it STILL was giving me problems I did this. My exaust was located "just right" so I could do this next trick by myself with the hand that was gripping the fuselage. If you have a helper... it is easier. As I hit the starter.... I put my thumb over the exaust outlet for an INSTANT. (easy though....NOT even 1 second....just on and off....you will discover how long by doing it.). With the starter cranking, and your finger/thumb over the exaust outlet, it directs ALL the pressure from the compression stoke into the tank. Instant fuel to your line and carb!!!;) NEXT..I assume you rechecked as AirGar suggested: check your low and high end settings so you have a smooth trasition from idle to instant full throttle. With that being said I have to hand the ball off to someone else....except for one thought. You said you had peak rpms and then went rich by 1/4 to 1/2 turn. My only suggestion here is to just TRY a little richer than that. As far as it bogging down when held nose down..... I am lost except for incorrect tank placement in relationship to the carb. I am thinking this is an ARF (??) and it is basically a factory set up, so it should be ok. PLEASE keep us posted as to the final outcome.
... Good luck..lownslo

lownslo,

Apparently Steve IS running an 11x7.5 prop. (This is probably the best all around prop for this size motor.)

Steve,

After re-reading this post, I thought about something else that could be happening, and that is the clunk hitting the back of the tank, thus cutting off and/or restricting the fuel to the carb. Make sure the clunk line is well short enough (about 1/4" from the back of the tank) to keep the clunk "free" whether nose up or nose down.

Keep us informed!

Gary

ok, i gotta send yous guys some pictures..... i will take some this weekend and post 'em monday.

I really appreciate all the help, I have been in r/c since the late seventies..... small garbage from radio shack first all the way up to 1/4 scale offroad cars with 30cc motors that would jump 10' high & 30' long ..... i have alotta experience with glow... built two planes from sheeted balsa & blueprints... uggg whatta experience for a 15 yr old !!!! havent flown in over 15 yrs and am just getting back into the hobby.

soooooo.... that being said, i really appreciate all the help you gentlemen have given me.... no knocks on the arf yet?

anyway, yesterday, i took the tank out... yes, the clunk line was too long.... binding against the back wall.i shortened it so it is about 3/4 of the tank's length.Is that correct? so if the plane is nose down, hauling ass towards mother earth with a half tank, the clunk is kinda like a fish outa water.... sucking air. I would have just whats left in the line to avoid iminent disaster? (this is my only dilema right now) replaced the inlet & pressure lines again. put an inline filter on carb inlet close to carb so i can disconnect at filter to fill 'er up. The idea of the finger over the exhaust is a great idea.... twould nevera thunk it!! I really need to play with the idle mix setting, see what i come up with. i read a post on here that was pretty detailed on the adjustments.

ok guys, i will send a picture of the plane, and keep up with my progress, i am corresponding with Paul Grayson, i guy i met here who also has a Thunder Tiger Trainer .60 ( huge, absolutely friggen huge) and he has flown it with an instructor for nine flights so far, he is working up to taking off, then he will do landings. Anyone else ever have one of these awesome kits??????????



i am anxious to get 'er up in der luft.

Steve-o

Steve,

Houston....I think we've found the problem! :D

3/4 back should be fine, remember, the pressure from the exhaust keeps the fuel going thru the clunk and to the motor, this is why everything needs to be "air tight".

On another note, I don't use "inline" filters on the plane (just another thing to cause problems), I simply filter the fuel in the "fill" line.

Be extra careful when you use the muffler priming method as it can get awkward, you almost need a 3rd hand!

I had the Tiger 60 trainer many years ago and it was a great flying plane, you should have a blast with it!!

Have fun, and let us know if this corrected the problem!

Gary

Steve, (Your Quote):The idea of the finger over the exhaust is a great idea.... twould nevera thunk it!! I really need to play with the idle mix setting, see what i come up with. i read a post on here that was pretty detailed on the adjustments. (End Quote). AirGar mentioned about being careful. (finger over muffler outlet/priming). I tried to convey that in my post but I seemed direct the "being careful" to the flooding situation and not the possible danger here. :rolleyes: YES... by all means, try for that 3rd hand from a helper if possible!!! (I also do this as a last resort). Also.... you mentioned about the carb setting post. I will try to find one that I think is VERY good... AND it may be the same one you saw. This guy is in our club and is VERY knowledgeable. I just edited this post as I have found the post right here on this forum. Here is the link to go directly to "carburetor adjusting 101" ... Good luck..... lownslo.

carb 101