ST 3250 transition problems
05-12-2003 | 05:56 PM
#1
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From: Torino, ITALY
ST 3250 transition problems
Hello from Italy !!
I have just finished the construction of S2G tow, the TUG, motorized with Supertigre 3250.
With the original muffler, perry pump and mixture 12% oil, 1% nitro I can get (with 18 x 8 prop) 7700 RPM, terrible.
Great problems to take off with the tow alone!! (9,5 kg of model)
Replaced the muffler with a KS 50 tuned pipe tuned at 63 cm, with the same fuel, pump and propeller, I obtained a fantastic power. 9400 turns and towing of glider 12 Kg and 5,5 mt.
Only a problem now.
Full throttle - No problem.
Idle - 1900/2000 rpm for hours.
Half throttle - Haaarrrrgggg. Smokes, too rich, a real disaster.
I heard abount replacing the carburetor with a OS 7, to turn some degrees the spaybar, take a trip to Luordes......
Someone has good ideas?
Thanks to all Denis
I have just finished the construction of S2G tow, the TUG, motorized with Supertigre 3250.
With the original muffler, perry pump and mixture 12% oil, 1% nitro I can get (with 18 x 8 prop) 7700 RPM, terrible.
Great problems to take off with the tow alone!! (9,5 kg of model)
Replaced the muffler with a KS 50 tuned pipe tuned at 63 cm, with the same fuel, pump and propeller, I obtained a fantastic power. 9400 turns and towing of glider 12 Kg and 5,5 mt.
Only a problem now.
Full throttle - No problem.
Idle - 1900/2000 rpm for hours.
Half throttle - Haaarrrrgggg. Smokes, too rich, a real disaster.
I heard abount replacing the carburetor with a OS 7, to turn some degrees the spaybar, take a trip to Luordes......
Someone has good ideas?
Thanks to all Denis
05-13-2003 | 01:49 PM
#2
My Feedback: (11)
ST 3250 transition problems
Denis,
Usually, if the midrange of the engine is too rich, then the idle mixture will need to be leaned a bit. This will require you to raise the idle RPM a bit and reset the high-speed needle. You should be able to eventually get an adjustment that will work nicely.
Don't worry about raising the idle RPM a bit. The idle RPM you're getting would be considered on the extrememly low side. We normally idle the engine at about 2,200 RPM or so. This insures a good transition.
Usually, if the midrange of the engine is too rich, then the idle mixture will need to be leaned a bit. This will require you to raise the idle RPM a bit and reset the high-speed needle. You should be able to eventually get an adjustment that will work nicely.
Don't worry about raising the idle RPM a bit. The idle RPM you're getting would be considered on the extrememly low side. We normally idle the engine at about 2,200 RPM or so. This insures a good transition.
