OK have a T/L 60 powered Big Job. lap times at 4.8 to 5 sec  RPM 8,600 Prop wide blade 123/8 x 6 carbon .

the motor is at a dead 4 stroke .i would like to increase the RPM a bit so that it will run a little cleaner and keep the same lap times . what are my choices, Oh, fuel is 10%

    Depitch it to 5.5", then see.

    Brett

lines are 62 ft eyelet to eyelet. will de pitch to 5.5 and see what happens

would that be better than shortening the prop

it fly's great as it is, plenty of pull, just sounds like it will quit at any minate

First thing you should do is drop the nitro to 5%, this time of year power is no issue, or should not be with a ST 60 on a BigJob, that prop is small for a ST 60, so don't cut the diameter down, most people using my 60s run a 13 inch 2 or 3 blade, That will help clean up the run
Next is to make sure you have a good..hot.. plug... A Glow Devil 300, T-Bolt RC long , and similar p;lugs  run well in the ST 60. The 60 will cycle very cleanly if setup properly
You never mentioned the Venturie or restrictor size, that is also a great trimming tool.

But just dropping the nitro, to get the same run you will need to lean the needle, that may do it without any other changes
If  not I would consider going to 63 ft lines eyelet to eyelet , You have  just a small problem, it won't take much to get it trimmed as you want
I setup over 600 of the ST 60s for people, and this all worked well for them, as the weather gets warmer  you can bump-up the  nitro...if you need it.

Randy