Post by ChiMike on Mar 20, 2018 4:20:03 GMT
I experienced an issue in February flying from Gary-Chicago to Symrna, TN. Cruising at 8,500 ft, approx 5200-5300 rpm and 110 IAS, I noted I was losing rpm’s-20-30 every half minute. Advancing the throttle caused the motor to lose even more power. By slightly moving the throttle back I would find a sweet spot and hold 5000-5200 rpm for a few minutes, then have to manipulate the throttle again. This went on the balance of the flight.
I checked both tanks, fuel pump on and off, attempted to indent into turbo—that was a big no—and simply could not get a stable rpm. I had ‘enough’ engine power—but not normal responsiveness.
The flight back a coulple of days later was ok: I held a 5000-5200 rpm most of the way, only a little of the rpm loss I’d experienced before.
After consulting with the team at Midwest SkySport they talked to Rotax and surmised I had an issue with the carburetor gasket to the float bowls. Parts were ordered, based upon the Rotax recommendation, and when my schedule and the weather aligned I flew over for what was expected to be a 3-4 hour job and head back home.
Unfortunately the parts provided were defective and did not correct the issue. So—a car trip home while th plane stayed behind. The team at Midwest worked with the Rotax people to figure out what the problem was. It turns out the gaskets first recommended were bad—and Rotax said the float bowls should be upgraded.
Bottom line—fuel system checked from front to back, new gascolator screens (not the issue but good to do) and the latest float bowl/ gaskets for the 914.
Picked up the plane last Wednesday: tight schedule and brisk winds meant just get home. No issues. Sunday I had both weather and time to do a full shakedown of the plane: full responsiveness of the throttle, full speed, no issues at all with rpm loss or non responsiveness. Flew for ninety minutes at a variety of settings. Level flight at 115 kias—then indent for full throttle quickly put the manifold pressure in the red (and 130+ kias). Did a full climb from 6,500 cruise at 5400 rpm 115 kias to 8,500 at 800-900 fpm, full indent, at 85 kias, and back to 115. Descents were easily in the 5600+ rpm range before throttle back.
First—Midwest did a great job getting the issue identified then solved with Rotax. They know the Rotax engines and are learning how to service Tecnams as well. (They also handle Flight Design, Czech Sport, Cessna, and are the U.S. rep for Sling.)
Second—if you have any intermittent issues with unexplained rpm loss, you may also have the same type of mechanical defect as I experienced. Rotax may be looking at another advisory that is more expansive than the prior one that addressed this issue: my engine S-N was not part of that initial one.
Please let me know if this assisted anyone.
I checked both tanks, fuel pump on and off, attempted to indent into turbo—that was a big no—and simply could not get a stable rpm. I had ‘enough’ engine power—but not normal responsiveness.
The flight back a coulple of days later was ok: I held a 5000-5200 rpm most of the way, only a little of the rpm loss I’d experienced before.
After consulting with the team at Midwest SkySport they talked to Rotax and surmised I had an issue with the carburetor gasket to the float bowls. Parts were ordered, based upon the Rotax recommendation, and when my schedule and the weather aligned I flew over for what was expected to be a 3-4 hour job and head back home.
Unfortunately the parts provided were defective and did not correct the issue. So—a car trip home while th plane stayed behind. The team at Midwest worked with the Rotax people to figure out what the problem was. It turns out the gaskets first recommended were bad—and Rotax said the float bowls should be upgraded.
Bottom line—fuel system checked from front to back, new gascolator screens (not the issue but good to do) and the latest float bowl/ gaskets for the 914.
Picked up the plane last Wednesday: tight schedule and brisk winds meant just get home. No issues. Sunday I had both weather and time to do a full shakedown of the plane: full responsiveness of the throttle, full speed, no issues at all with rpm loss or non responsiveness. Flew for ninety minutes at a variety of settings. Level flight at 115 kias—then indent for full throttle quickly put the manifold pressure in the red (and 130+ kias). Did a full climb from 6,500 cruise at 5400 rpm 115 kias to 8,500 at 800-900 fpm, full indent, at 85 kias, and back to 115. Descents were easily in the 5600+ rpm range before throttle back.
First—Midwest did a great job getting the issue identified then solved with Rotax. They know the Rotax engines and are learning how to service Tecnams as well. (They also handle Flight Design, Czech Sport, Cessna, and are the U.S. rep for Sling.)
Second—if you have any intermittent issues with unexplained rpm loss, you may also have the same type of mechanical defect as I experienced. Rotax may be looking at another advisory that is more expansive than the prior one that addressed this issue: my engine S-N was not part of that initial one.
Please let me know if this assisted anyone.
