I must say that I am a littlle disappointed in the performance, quality out of my new SUPERTIGRE 75. I am flying it in a 4* 60. Absolutely no verticle power whatsoever. The engine does not want to shut off when the carb is 100% closed.Also, while flying the other day, my plane started making a loud rattling sound. I hurried and landed to discover that a washer had come loose inside my muffler??? Cant fly without a muffler.
The RPM listed for this engine is 15,600. The most I can get out of it is 10,000. Supertigre says this is normal. I have'nt been flying r/c that long so maybe my expectations were just too high. Think I will just spend the extra money next time and go with OS.
Almost forgot, the glow plug was bad right out of the box too.

Was your Super Tigre made in Italy or China?

I have problems with my gp aswell. it has stupid intermitent problems like wont start on a cold day and other little crap. the engine has no guts just like yours and was imposible to start untill I got a electrict starter and cracked it for 30 min. I was so pissed!!! peaople say your a mad model flyer just cause of one bad comment about the thunder tiger and they told me (going on for hours on end about how "good" it was) and calling me a blatent lyer for saying some thing bad about them.
my advise is to not put any more money or time into thunder tiger engines and stick with a brand that is good. im even considering goind electric and ditching these glow engines all to gether.

is the needle valve setting correct? Try to lean it out... or smaller prop

In my opinion, the chinese ones are way better than the old ones[8D]

Mine is the China version. There was another 4* 60 at the field. It had a os 61 FX. Just from watching it fly it appeared to have more power than my 75.
I have a tach, it is leaned out to the max, then I back off a few hundred rpm. I am running a 12/8. I have also tried a 12/7.

We shall see..... I have an old (made in Italy) G90 in a Top Flite P-39. Once the engine was broken in, which by the way takes about a gallon and a half of fuel, at a minimum, it has been one of the most reliable, certainly the most powerfull 2 stroke in my inventory. I also have a GS 40 that was a great running little engine untill it injested the wire off a glow plug, but that wasn't it's fault.
I just picked up a brand new G 2300, and my initial impressions are very good. It's also going in a large warbird, so reliability is going to be paramount.

Now, as far as the original problem in this post, check a few things. First, is the backplate tight, and is there a gasket in there? Second, is there actually an "O" ring between your carb and the engine? If either of those above mentioned things are wrong, loose or missing, the engine will not run right, and won't shut off either. Also, what prop are you running? You're not grossly overpowered on your 4*, so maybee a larger, flatter pitch prop would help your vertical?

And yes, most manufacturer's ratings for RPM are somewhat overestimated. Saito's RPM range on a lot of their 4 strokes is up to 12K rpm. The most you'll ever catch my 4 stroke Saito's turning is just a hair over 10K.



Andy

If there is a problem with the engine outside of the way you have it set-up then return it...

SuperTigre engines have been around for a long long time and in general are wicked...

I now have Chinese and Italian models and I have not had any trouble with them... The Chinese ones are as good, if not better than the Italian ones...

I have a G-90 in a 4 Star 60 and it has BAGS of power...

I would suggest that you tighten the screws holding the manifold to the engine, and lock tight them. I also seal my gaskets with gasket sealer stuff...

In my opinion you don't lose anything over an OS engine when using SuperTigre...

Don't judge the whole case by one bad apple...

Matt

This is a ringed engine and should be run quite rich for a gallon of fuel or so, and after that a lean run might ruin the ring. If it only turns a 12x8 10000 rpm return it to get repaired, it should turn it around 11500. Also try a larger diameter lower pitch prop if you would like more vertical performance, like a 13x5,13x6, or a 14x4. The high rpm number they list is usually the maximum rpm (redline) not the recommended rpm.

I suspect that Cogburn is on the right track -- the engine may not have been broken in correctly -- a fatal mistake with a ringed engine.

Give me a break! I said I was fairly new to r/c. I did'nt say I was an idiot! I have been flying controlline for years. The engine was broke in with 10% nitro 20% oil. Bottom line: my engine is turning 10,000 rpm with the 12/8 prop. SUPERTIGRE SAID THIS IS NORMAL. Why should I return it? The engine was broke in by the book. Slobbering rich. The delay when I throttle off is a small nuiance. Not a big deal. The lack of power is just disappointing. Period. The engine is performing as Supertigre says it should. This is just a weak engine in my opinion.

Sorry to hear your dissapointment in your new ST. If it performs like that and it is fully broke in then there is obviously something wrong. 5600 RPM loss cant be normal. ST can be very finicky for adjustments. I have had a ST 75 (the old style) for 8 years and it has been really reliable.

The shut off can be a possible low end setting not quite right. As far as the RPM loss goes it is either defective, not broke in or adjustment is wrong. Also, try a lower pitch prop for better climb (specs call for a 12X6 or 13X6).

tks1

The only problem I have had with ST is getting one (as per my post in the engine forum).

pelham

Check all the head and backplate bolts. Also, check the nut on the high end neddle. It sounds like you may have an air problem. go with the lower prop. I have been flying for years and the Super Tigres are great engines. I do not think anyone was calling you an idiot, rather trying to help. I have a Super Tigre in an 60 size 300 Extra and get around 15 K. The engine should performe better than that. Why return it, get what you paid for. That is what the warranty is for.

I am running an APC 11" on mine.

Hi pelham,

If you are happy with the running in, I certainly agree all is not well. A ST 75 in my Super Chipmunk turning a 12.5 x 6 Bolly has great verticle performance. In a 4 Star 60 it should be amazing.

If you have eliminated any air leaks check there isn't any casting flash blocking the engine pipe or muffler. If not back to the agent for warranty or replacement.

Cheers,

Colin

When the engine companies give a hp rating it is usually at a much higher speed than the speed you would normally run at. 15,600 must be where you would find peak hp, and now doubt you could get that with a 11-5 or 10-6. But I would stick either a 12-6 or 13-5 on it so that it would turn around 12,000. I flew one for hundreds of flights with no problems on those two prop sizes.

A lot of people have trouble setting the mixture on ST engines. Unlike most engines, you can adjust the midrange mixture as well as the high and low speed needles.

Personally, I liked the older Tigres better, before the clunky heads and cast drive washers. But since most RC pilots fry their engines on every run, I guess the bigger heat sinks became necessary. For the most part, people that flew control line (not talking Cox here) have a better feel for running engines.

The RC crowd also has problems with locating fuel tanks with respect to the carb. Nearly every "trainer" has the tank mounted too low. I guess it's more important to look like a Cessna than to run well.

Maybe one day, the engine guys will figure out that the airplane designers are slow learners. Then they will rotate the carb so it is on the side of the engine.

I personally think a 12X8 prop is a bit much on the ST 75. I usually run a 12X6 or 13X6 depending on the type of prop on that engine. Mine is an older italian version, but it runs great. I doubt that a 12 inch prop will give unlimited verticle on the four star, but running a 13 or 14 inch prop that is pitched accordingly would do a better job in the verticle department. I don't use a tach all that often, but if I remember correctly, I can get about 12,000 rpm on a 12X6 prop.

Thanks for the input guys, I think I will return it and see what can be done.

Have a ST 75 in a CG Ultimate and it has been an outstanding motor from the begining. Also have OS, Saitio, Thunder Tiger. But, interesting original post for the Beginners forum rather than engines.

I am another unhappy ST buyer.

I have a ST75 that also will not shut down, the carb barrel does not seem to close completely unless I remove the end plate that carries the fuel nipple. With the plate in place there is a significant opening on the barrel still visible.

This motor (which was one of the older Italian jobs) used to live in my TF Corsair until I got tired of dead sticks.

Also had a ST61, this was no better at staying going, I sold it cheaply to someone after telling them the full story.


Terry

One thing to note is that the prop blades on 12x8 prop are stalled (on the ground or below about 15MPH) at 10000 RPM. This makes for really bad performance (an effiecency of just a few percent) at low speeds, like when climbing vertical. A 13x5 or 13x6 seems like the right choice.

Well, if you go with OS or any other brand of that size,your going to have the same problem. The 4* 60 is a 7-8 lb plane with a 71 inch wingspan. I have no idea what prop your using but I am sure it only adds to the problem. You simply have a bad combination and your underpowered for the size of the plane.

Separately, you have a good plane and a good engine. As far as it not shutting off, that is simple adjustment. Whoever you have as an "advisor" is not doing a good job.

You may never get 15000 RPM and probably don't want to fly at that RPM either. I have the ST 75 on my Tiger 60 and have swapped out props to get the performance I want/need. Mine will go vertical and accelerate so it's a matter of prop selection. I believe I am now using a 14-5 or some such thing on there.

Go for diameter with low pitch and check rpm then take off and go vertical. You will see that it will begin to really perform once you get the right combination. With that prop, it turns about 10,500 rpm and I get good performance. Actually, that's where the torque curve peaks out, even though the HP is rated at 15,000 rpm, that's not the normal suggested operating rpm. All the pattern guys will tell you the same thing, but one thing they do stress.. noise does not equal power.

Mine also had a loose part in the muffler. I took it apart and fixed it and went back up.

As far as the idle is concerned, well, mine idles just fine at about 2300 rpm and lands just fine at that setting although it landed great on the smaller OS62SF I had on it before I put the ST 75.

I agree with the people who suggest you're over propped. Go to a 6 inch pitch and see if it isn't better.

Buy some longer muffler screws and put a nyloc nut on them...the muffler will never vibrate loose.

Don