ORIGINAL: Flyer95
ORIGINAL: T28RON
I have a ST-75 and am getting 8220 RPMs with a attached to a Astro Hog Bipe. 13 X6 prop. I can barely get it up. I would think that I should be getting at least 9/10,000. I have no leaks, new fuel, and new plug. I am useing omega 15% with 16% synthetic. I was told a long time ago by a flyer that works for Hobby bench in Phx that all 15% has 16% synthetic oil. should I drop to a 12 X 8 to get more RPMs??????? Thanks.
Ron
Your rpm seems low. That engine should turn a 13x6 about 10500-11000rpm "right out of the box". Maybe you can look at the piston ring if it is worn out or if it might be something else restricting the power? Also one more thing, super tiger always recommended that part of the oil content in the fuel is castor oil.
While I don't doubt an ST .75 will turn a 13-6 I think your figure is a bit optimistic. I have a ST .91 and it will barely do better than 11,000 with a 13-6. Though it has been a while since I ran it and the .75 may be a better performer.