I have a ST 3000 that is giving me fits. I have done a search on this site reading all I can. Here is a brief of my engine. Starts first flip every time, runs well trasitions well, BUT it all of a sudden quite with no warning. at different times in the flight. No spuutering or rough running, just like it ran out of fuel or blew a plug but both are ok. I have read that i I switch to an OS 7D carb it should clean up my problem. On hand I have a 7L carb from an )S .61 sf. what is the different in carbs. Both the ST and OS 7L look to be the same size and fit interchangably. I am going to try it in the AM but what is you 2 cents worth.
Dave

....The flange size on the ST 3000 is 15mm., same as
the OS 7D carb off the OS 1.08 FSR. The 7L is the same.

Dave.

Exactly - replacing with a 7L will be like putting the standard small carb on the 3000, using the 7D will be like putting the BIG ST4500 carb on it.

And just as a test, you might dilute your standard fuel with methanol so its about 10-12% oil - use a hotter plug/colder plug.

I've used the OS and ASP carbs as well as the ST4500 carb - all work ok if you take some time, just start with the high adjust, then do the low needle, then back and forth high to low a couple of times. Run it smoking rich for the first flights and see if they last the whole flights, then dial it in a quarter turn a flight till you're running ok with smoke showing once in a while.

I also put a constant glow system on mine, keeps the plug hot all the time and I haven't had an engine go out since I put it on. Just a pair of wires off a four cell, c-sized battery pack with a cut off switch on it.

Dave, A few years ago I've had similar problems with my ST 2500, as well as my stepfather with his ST 4500. We got a recommended set-up for AnnMarie Cross from Hobbico at that time. Follwing the set-up all our problems were solved. My ST 2500 is mounted sideways in a CAP 231, My stepfathers in mounted inverted in a Bryon RYAN STA. If you want to try her set-up before you change carbs, I put it out yesterday in the fun-fly section. Look under "super tigre vs.". At the bottom of the 1st page is my post describing her set-up. It's a timely set-up but it worked great on all my ST's. LOL

KEVIN

What fuel are you running?
What alttitude are you at?
These all factor in, if you are around 3000 ft then you would most likely need to get the larger carb but you can get them to rin good if you take your time in set up. Not to judge, but how is your engine set up - possibly your shy on your low end and to lean on take off and shes overheating. The type of fuel ,preferably supertiger mix cool power will also cause this. Hope this helps. My two cents.

Like FLYING MOUNTIE said, your most likely too lean or not getting proper airflow to/from the engine and it's getting hot. My 2500 did this. My setup: lots of cooling inlets/outlets, Perry carb, OS F plug, and Omega 15%. Runs stronger than most newer motors, swings a Mezjlik 18X8 @ 8900rpm. Keep it cool and lubed and it will run well for you.

Here's how we set SuperTigre carbs. A few iterations of working with the idle and high-speed mixtures, and the engines usually run very well.

Please be aware that 1-2 tanks of fuel does not "break in' a SuperTigre engine. As they get running time on them, they generally improve. They should take a good "set" after about a gallon or so.

Here's the carb setting link:

http://www.supertigre.com/faq/product-faq.html#q14