Conversion of C75-12F to C85

William, you have a cruise prop. Don't expect it to give you amazing climb out, but you'll pick up a few more mph on cruise than a climb prop would give you. Just may take you a little extra time to get to cruise altitude. If you don't have any obstacles to worry about taking off from your home airport, you'll be fine.

Mine has the 7150 but I have a C85 'stroked' with an 0-200 crank and it climbs very nicely with 400 pounds of people and full fuel.

Larry, what do you mean "get the prop cut and re pitched ? mine is 7150 . . . .

Bill James

Larry etal

I have been trying to get a handle on a problem with my 415-C with the Cont 85-12 engine. This engine even has a Continental metal tag on the engine showing it to be 85HP and 2575 max RPM . . . I have a new McCauley 1290/CM7150 prop, overhauled carb to make adjustment to the C-85 . . . I can get about 2200 static RPM , but in flight I can get only about 2350 to 2400 RPM at full throttle I generally must fly with FULL THROTTLE to get 2350 to 2400 RPM.I have the "long pull" mixture control so I can achieve lean operation burning about 5.6 GPH @2350 RPM. The engine compression are all mid 70's or better . I have had several club responses but none have hit the mark. I have had the induction system completely examined . . new plugs , harness checked. .Take-off and climb is anemic. The plane is great except for this problem . I have 2 15 gal wing tanks and NO header tank.
SURE COULD USE SOME FRESH IDEAS !!!

Thanks!!

I stand corrected the TCDS is the standard. The knowledge base here is so impressive. I always enjoy the read. I always learn something new. When I started flying over 50 years ago an IP told me: "The day you don't learn something, is the day you should quit flying!". Thank you for the info.

Arlan
N3989H