If you don't see any improvement in the next 5-10 hours, I would give up, remove the cylinders, light hone them, re-ring the pistons and start all over again.
If you see improvement over the next few hours, hang in there and keep trying.
If you are not at a semi acceptable level of consumption with continued trend toward improvement by the time you get to 25 hours, it is likely good break in will never happen.
If you have to re- ring, I have used this break in schedule for running in cylinders on engines installed in aircraft successfully many, many times.
1] Install mineral oil in the engine.
2] Start engine, run at 800 R.P.M.'s for three (3) minutes, shut down, check for leaks.
3] Start engine, run at 1,000 R.P.M.'s for three (3) minutes, shut down, check for leaks.
4] Cowl aircraft.
5] Start engine, run at 1,200 R.P.M.'s for three (3) minutes, shut down, park into the wind.
6] Start engine, run at 1,400 R.P.M.'s for five (5) minutes, shut down, park into wind.
7] Start engine, run at 1,400 R.P.M.'s for ten minutes, shut down, park into wind.
8] Start engine, run at 1,400 R.P.M.'s for five (5) minutes, run up to full power, check all engine parameters, retard power to 1,000 R.P.M. for one (1) minute, shut down.
9] Check for leaks, return engine to service (see Engine Break-In Instructions).
All runs should be made into the wind.
At no time during these runs should CHT exceed 350?F.
Between all engine runs, allow adequate cool off time.
Before proceeding to next run, you should be able to hold your hand on a rear cylinder head for three to five seconds.
For the break in period once the above is completed and you are flying, I would follow this protocol:
Use full power for take off and initial climb. Reduce power to normal climb power at 500 feet. Keep climbs shallow, add 10 M.P.H. to best rate of climb airspeeds and use this as a guide to how steep your climb should be.
When setting up cruise power, use 70-75% power.
Lean the engine in cruise flight by leaning to peak E.G.T. and enrichening a minimum of 50 degrees.
Please do not use the aircraft in training type operations (e.g. touch and goes, stall series, zero thrust and single engine operations, pattern work) for the first 15 hours of operation.
Good Luck and Happy New year,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."