Lochness

I'm new to this forum, but have been flying small planes for 30 yrs. Has anyone out there used the Thunder tiger 07 engines? I bought 2 of them brand new and neither of them will run for more than a few minutes!! I have tried diff. plugs, diff. fuel, tank setups, etc. They seem to run only till they get warmed up well and then they seem to have trouble drawing fuel. It is hard to tell for sure, but both do exactly the same thing. I have run enough fuel thru them to break them in somewhat, but no luck. I am running muffler pressure, and even tried a carb extension to increase draw. I am hoping someone out there might have some ideas??? Thanks for any help. BTW this forum is great, I use diesels, co2 engines, cox, glow etc. I also fly the micro electrics in co2 and electric......

flyinrog

My Feedback: (1)

try a search, but its a forum full of coxests and norvelites, you very rarely see a thunder tiger here, if you hooked both engines to the same tank, maybe there is a air leak in the system somewhere, I understand its a good quality engine but heavy for its size,,sounds like if you have that much experience you would have covered anything that i can think of.. maybe the fuel is it the same?....air bubbless in the fuel line?

Lynn S

I have noticed on my norvel that it will start to get air bubbles in the fuel line when it starts to go lean, and the engine will try to die unless I open the needle some.It also will start going lean when the tank is about half full sometimes. So I guess it needs to be a little more on the rich side when started. The needle setting is very critical. I'm still learning. It seems like If I set for maximum rpm then it will go lean easily in minute or two. A good setting on a full tank is not good when the tank is half empty. If you start out running a little rich then it should not lean out enough for the engine to die.
I'm sure there are guys here that know a lot more than me, but this is one thing I have noticed about my .074.

johnvb-RCU

My Feedback: (1)

It sounds like it's starving. I use the narrow guage fuel tube to the needle. Wide guage stuff might be causing draw problems. Also tank height?

Big Al-RCU

Lockness,
Since you have two examples that behave the same, I would, as Rog suggested, look for something in common with the two test setups, maybe the tank, line etc.
Secondly, I know that I have been fooled by an engine that heated up, got tight and died, with one that had a fuel draw problem.
Having said that, which no doubt didn’t help at all, welcome to the forum. Even tho the TT may not be the most popular engine on the site, there are several members that do have experience with them and hopefully they will step up to the plate. As an engineer in a previous life, I would like to think that all engines have to obey the laws of physics, but the truth of the matter is that they do seem to have their own inexplicable personalities.
Al Lenz

Bipe Flyer

I have a TT .07. On mine the needle assy came loose, causing the engine to quit. Be very careful if you try to tighten it though, I broke mine and had to buy a new assy.

fireman7875

My Feedback: (7)

I have a TT 07. Great running engine but no power. I had the same problem you are having. The problem was solved by a series of changes.

First, I had to back the needle out a little for flight. This engine seems to be very susceptible to lean runs once the prop unloads.

Next, I changed the prop I was using. I started with a 6-3. Couldn't keep up with the high RPM. I ended up using a 7-4. Sounds odd doesn't it?

Lastly, I changed my fuel to 10% with a lot of castor. This kept the engine cool and prevented overheating.

Like I said before, I found it to be a sweet running engine but it is too heavy and lacks the power for most airplanes that require an engine of this size.

Good luck with yours and let us know what you come up with.

Bipe Flyer

I use a 7X3 on mine. It deosn't like 20% castor becasue it tends to put out th OS #8. I run mine on Omega 15% nitro. Heavy, good runner, nice idle, moderate power.
Click this link to see it flying a 17.5 oz Stik.
http://donatelli.net/default.asp?pla...t=12a&vid=true

Lochness

I really appreciate all the help guys! You gave me several ideas to try out on the tt07. very good advice and help. It sounds like it is a very tempramental little sucker!

Lynn S

Tell me about it. Let my Norvel .074 get a too lean and wham, the engine locks and the prop nut and prop will fly off. I guess it's not broken in yet.

CrocEnd

HY Bipe nice vido's of the stik nice country. What size Stik,
don't worry if bigger than .074, My LS is 24 inch with Cox .020
throttled , magic.
Cheer's Croc.

Bipe Flyer

Thanks CrocEnd,

Here are the specs on the Stik.

Wingspan: 32.5" (81.8cm)
Length: 26" (66cm)
Weight: 17.5 oz (496g)
Engine: Thunder Tiger .07
Channels: 3 T/A/E

tinyflier

I'm flying a TT-07 on a Norvel 1/2A "Tutor". I use a mix of 10% nitro and Norvel 35% with a 7x3 MA prop. Engine hand starts most of the time. Open the throttle to 1/2 or 1/3, after a generous prime and the motor should turn over or start by hand. If it locks up, hand crank until the prop flips easily then, and only then, use an electric starter. The engine is not terribly powerful but will turn about 16k, idles about 4-5k and flies a 25 oz plane with a moderate hand launch. Break in the engines carefully as all these small engines loose compression easily if over heated.

Lochness

Thanks Tinyflyer for the help on the TT07 I am going to try it again with your suggestions and see what happens...Thanks again

Cat 1

My Feedback: (1)

I was very interested to read all the discussion on the .07 and a lot of it confirms my experiences with this little engine. I had a plane (own design) which had a Norvel .061 in it and the thing flew great but my little Russian did not have a reliable idle. I thought the TT.07 would be a great choice. I purchased one and the fun began. First off, it has been a long time since I have had such "FUN" with an engine. The thing would not hold a needle setting until I had run 16 oz. of fuel through it. A lot of plug and prop experimenting and finally got the thing running like a top. One problem- no power. The thing was not as powerful as the .061 and the plane barely flew. After spending the better part of a day on this beast I was not about to give up. I pulled it apart and looked for the "power robber". Port timing, parts fit and everything seemed reasonable, All except for the liner to case port alignment. There is at least .125" of the liner that has no recess in the case on the top of the main transfer and a little less on the boost ports. The bottom of the ports is also very shrouded.

To make a long story short- 10 minutes with the dremel and a gain of 1200 rpm on a 7-4 apc and more on the smaller props.

The plane now flies with authority and it has as least as much power as the norvel. It still idles and transitions great.

here is my current setup: APC 7-4, 10% nitro 22% oil-1/2 castor
O.S. #8 plug. 11300 RPM set slightly rich.

ZB50

I'll pipe in with my TT .07 experience. I built an Ace P51 (you know, the small ones). I had ran the engine on the test stand for a few tanks of 25% omega with a 7-4 APC. I don't remember the top end rpm but it seemed good. The 07 would idle quite well with a fox short standard plug. I must say I liked the looks and manor of this engine. When it came time to fly the mustang,,,,,,, Forget it ! I could tell there was not enough power to do the job. I tried other props but still was not satisfied enough to try it. I hated that. I sold the engine/plane and bought a Norvel .074, Night and day difference.

ZB

tinyflier

This 07 engine is very sensitive to running lean. IMO, it will lean out in flight more than is appreciated. Starting it rich and flying for a minute or so is anxious but you can tell when the mix changes because the plane begins to climb and/or pick up airspeed. If started lean it will become overly lean in flight and immediately loose power as it overheats. Check the RPM's before flight with 30 seconds of nose up at WOT, if there is a drop in the RPM's it's too lean and will only get worse in flight. It also leans out as the fuel tank empties and the driving pressure from the muffler drops. These small engines are FUN!

goldguy

I have two TT .07's and they both are great little engines. I also have two Norvel .074's and don't seem to notice much difference in power. They are very well made and have a better carb and more reliable idle. I use 25% nitro, a 7 X 3 MA prop and an O.S. plug with mine.

The first one I had a problem with, couldn't get it to run worth a darn. Took the carb apart and found a gob of snotty substance in there that came from the factory. Removed it and presto, problem solved. The second one no problem at all.

I have lots of time on one which powers my kit bashed Aqua Star and I have never had to get the fetch boat out to retrieve it. I think is I was using the Norvel on it I would be getting some exercise on those oars.

fly SMALL, have a BALL

Bipe Flyer

Hey Frank, I'll glady trade you my TT .07 for one of your Norvel .074's.

goldguy

Just sold all my Cox engine/parts collection to a local modeler and when asked what I was going to spend the money on, I told him electric goodies.

His comment was, but Frank, it's got no sound, it's got no smell, it's got no soul!!!!

But I have to tell you guys, I have some 1/2A sized "E" stuff that rivals glow. You really don't have to spend much money to make it work with cheap Mabuchi can motors, with the right drive train and fuel supply.

There are rumors abound locally that I have sold out to electric, not true, just playing around and having some fun. Hey, I like to fly U/C and FF as well.

Lochness

This forum is wonderful!!! I cant believe all the good advice and help I have gotten on the tt07. I appreciate it very much... I hope I can help someone else at some time, I have about 30 yrs. of doing this stuff, but you just never have all the answers! Thanks again

CrocEnd

ALL NOVEL .074 donation's gladly excepted
Croc