he guys iam looking at a super tigre engines the .75 and the .90 how are theses engines and are they reliable... I am about 4 months into this hobby and the only motors i have messed with are magum and Os... so how do these super tigre compare for the price

Well, some will tell you they love them, some will tell you they do not.

I am sort of in the middle. The only one I had was a .75 that was on a Tiger 60. It performed well, but leaked fuel quite a bit. But, in spite of that, it always ran well.

For the price, well, it's less than an OS, but no where near an OS in overal quality and performance. The OS .75 AX is a strong solid engine.. I have two of them. I also have three OS 1.20 AX engines and they are supurb.

CGr.

Ive found super tigre engines to be a bit touchy and prone to dead stick until they are broken in. After that though i love them.

I've had two. The first was an animal at wide open throttle but idle and transition were only so-so. I liked it though. The second was a nightmare. It never did run well. I know how to tune an engine too but I was beginning to question that with this thing.. I likely could have gotten to the bottom of it but I just gave the thing away rather than spend the time.

So if you get a good one, you'll love it. If not, you'll likely hate it. I think it is one of those things you have to try and decide for yourself.

I've only had OS engines and one cheap chinese made engine just to see what it was like. For me, i want to get into the air as quickly as possible. There was nothing more frustrating than driving 30 mins to get to the field and then not have your engine run correctly and dead stick each landing. I've decided I'll pay the premium for an O.S. going forward. I'm not saying that ST engines will be like my experience. But I'll pay the premium for something that will be easy to tune and gets me into the air quicker than anything else, especially given my very limited available time to fly.

Once my kid is out of the house or I'm retired and I have unlimited time to play with this hobby, I definitely intend to try out some other engine brands.

I have an ST G-51 on a Phoenix Sea Bee. I'm not a big fan of this engine, but I don't have big enough issues to replace it either. It idles rough but runs well WOT. This could be attributed to either tuning and/or break-in, but I will say that this engine has allowed me to improve my dead-stick landing technique on low-wing pattern ships. [:@]

I love my OS engines.

I have had two Super Tiger engines. A .51 and a .90 Both engines ran flawlwssly once tuned and did not give me dead stick fits. Now, that being said, I was told that the reason these two were good was the words "Made in Italy" on the side of the cases of both engines

Good point. I do not think the Super Tigre Engines being made today are as good as the older Italian ones.

In many of the threads on problems with SuperTigre engines, you'll see the same complaint pattern appear on SOME of the engines.

Namely, you can get a GREAT transition and high end, but idle bogs down... or you can get a GREAT idle and high end, but a lousy transition.

Supertigre suggests angling the "cats eye" venturi to help eliminate this problem, but that is a workaround not a real fix.

I have various SuperTigres and I find that they are most reliable and powerful when I forgo adjusting for a good reliable low idle.

I believe the problem is with the design of the throttle barrel.

There seems to be a large amount of air that makes it's way around the barrel where it is inserted into the carb letting the engine continue to run with the rich fuel mixture.

SuperTigre provides a rubber seal that covers this area, but I believe it is ineffective.

Normally my flights consist of:

- Start up engine and let it warm up at mid throttle
- Drop it to high idle and get plane out on runway ready for takeoff, at high ( rolling ) idle.
- Gun the engine quickly once or twice to clear excess fuel
- Takeoff
.
.
- On landing taxi in, kill throttle and set barrel fully closed.
- WAIT 30 seconds or more ( as the engine will continue to run fully closed! )
- Pinch off the fuel line and wait another 20 seconds for the engine to finally shut off!

I get NO deadsticks, but if I cure the overly rich idle condition, the transitions may kill the engine.

If it was not for this problem, which has been somewhat consistent accross engines, the SuperTigres would be a bargain and reliable.

Note:

In Sport Flyer magazine Oct 2007 I ran accross an article where the author was having a similiar issue with an Avistar .46 engine.

Try as he might, he could not cure the same problem.

Eventually he resorted to filing a small 2mm "half moon" on the throttle barrel opening at the point of smallest closure.

This increases the airflow at idle permitting a leaner low speed idle mixture.

I had an extra ST carb laying around, purchased in my attempts to cure the problems... so I tried the same thing with the ST carb.

Sure enough it fixed the problem PERFECTLY.

I've done this to two similiarly affected engines with equal success each time.

I hate to ask, but can you show a picture? (Tis better to ask a stupid question, that have to fix a stupid mistake...)

Okay, that has to go on your signature line now... In fact, that should be the motto in this forum

Now why wouldn't ST's engineers find this in their testing and modify their design accordingly? Am I expecting too much from a model engine company?

Why didn't Avistar fix the same problem with their engines?

Who knows?

Some people have speculated that the same carb design was used for different sized engines, causing a problem with the SuperTigres.



Bingo Field:

I'll try to find the original article and scan the pertinent pages.

I've got a SuperTigre 45 mounted in my Sig Somethin Extra. The engine has performed flawlessly, and the only dead sticks were fixed with a new glow plug. The only thing I've noticed is that they're heavier than the OS.

Hi!
All engines on the market are good!! I have been in this hobby for 34 years and I can assure you that there are no bad engines out there!

jaka,
You've obviously never owned an MDS.

As far as ST's are concerned, they are a superb engine if you take the time to break them in and tune them properly. Something no one seems to want to do these days. If it doesn't run perfect right out of the box it is considered junk.

I've got 3 of them... a pair of 40's on a Dual Ace and a 61 in a Harmon Rocket 3 - love them. Having said that when first two were new they both came close to being thrown across the field and into the plane-swallowing swamp, but by the third one I'd learned how to set them up and now won't waste money on any other brand of 2 stroke. (I only wish they'd start making 4 strokes - oh well.)

There's a couple of tricks with ST's...

- use low nitro fuels; 5% is heaps with them
- throw away the glow plug that they come with, it's rubbish. Replace it with an OS A3 plug.
- follow the break-in guidlines in the instruction, and when you think it's broken in it's still only 1/3 of the way there. These engines really get better with time.
- don't start twisting the fuel venturi round - you're only going to mask problems and create new ones
- make sure the carb's sealed well to the crankcase, there's no cracks or splits in the O ring round the carb's base, and that the pinch bolt's tight.

I flew my Harmon the other day for the first time in about a year. I'd stored it by squirting a bunch of auto transmission fluid into the carb & cylinder, but that was all I did. It fired up immediately, still transitioned perfectly, idled all day, and ran like a dream... just like both my 40's do. These are great engines, just misunderstood by the OS/Saito crowd who aren't prepared to put a few hours work into breaking them in and learning to tune them up. My only complaint with them is the big, ugly (but effective) mufflers and the dodgy muffler gasket - easily solved with an after-market muffler and leaving the gasket out, though I'm still using the standard mufflers (no gaskets) on my twin.

opjose-

Thanks I am REALLY glad I read this thread. I would love to see the article also. I have an Aviastar 46. It gets way too much fuel at low speed. If you try to lean it out at low speed- it affects the high speed. At first I thought it was just a POS, then I pulled off the pressure line from the muffler, wow what difference..this engine has potential..but I couldn't richen the engine up in high speed then. I was gonna drill a hole in the side of the carb and let some air bleed in but I think your fix will work....THANKS A TON-BW

Sandman,

I'll try lower nitro fuel and change out the glow plug in mine an see how it performs. As for the beer-can sized muffler, I've thought of painting it to look like a can of Coors light. I'ts about the same size. Maybe you can paint yours to look like a can of QB.

hehehe that'd be VB... or Fourex... and that's not such a bad idea.

Here you go!

This is from RC Sport Flyer - September 2008... ( It took me a while to pour through the old magazines to find the article! Whew! )

The first photo shows the modification to the Avistar carb, where I got the idea to do the same for the SuperTigre carbs.



The next two show the original article excerpt itself where this is discussed...

I do not file the half moon cut straight down the carb as in the photo above.

Rather I angled it slightly so that it forms an angled lip instead.

-

Also it is - NOT - a good idea to replace the SuperTigre provided plug with an O.S. A3 as suggested.

The A3 has a short profile, while the ST Plugs use the longer "nose" to prevent the element from getting fuel soaked.

In the following picture you can see the ST plug as the second to the right. Notice that it is just as long as an O.S. "F" plug, while the O.S. A3 plug on the right is considerably shorter.



This is a mistake I've seen many people make.

Nor an Evolution 1.00 NX!!! A true "work" ( POS )....

Thanks opjose thats what I had in mind for the Aviastar but the picture helps a ton. I think the Hobbyshop I got mine at had 3 including mine returned. If the fix works(which it should) I will pass it along.-BW

Point of note......You can use any O.S. glowplug that suits your needs. We tend to use the O.S. #6 (old A3) or #8 glowplugs with no problems. In fact, we believe that the O.S. #8 glowplug is just about the best general-purpose glow plug you can use. With low-nitro fuels (0% or 5%), the #6 is a good one to try. We use O.S. plugs all the time and strongly recommend them.