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Long story but i went to pick up my new to me Bristell with a 914T with about 800 hrs.

I had to do 2 hrs of instruction for insurance in the plane prior to accepting it to return home.  The day started off bad, because the dealer was installing new G3X software per my request.  The battery was low and we had to jump the plane.  It took several times and a 45 min charge to get it flyable.

We did a run-up and the motor seemed rough at idle but the ignition checks were fine. We talked to the mechanic and said we probably flooded the engine during our attempt to start it.  It reached 4000 RPM just fine but again low idle was an issue.

We shut down left it sit a few minutes and tried again and this time zero issues.  We took off and did two laps in the pattern just to verify no issues and then headed to a remote airport 15 miles away for our 2 hrs of instructions.   I started a turbo climb and noticed the manifold pressure at 40.1 so I backed off.  It shouldn't go that high, correct?  What if any damage could occur?

After backing off we levelled out at about 3000 feet and going over a small mtn that 1500' toward the airport we wanted to see what full cruise looked like as we were currently at 4800RPM.  I slowly advanced the throttle and when I got to 5100 the motor started violently shaking.  I backed off and it stopped.   We immediately turned toward the field about 8 miles away.

As we entered the pattern nothing had happened but when we pulled back for pattern work the engine once again was running round and occasionally shaking.  We turned base to final and things got worse   on short final the prop just stopped and we made the 1600' field

The dealer and crew was amazing, we had a mechanic out on a Saturday within 2 hrs and he immediately went to the carbs.  The engine just had it's 5 yr rubber complete and he said they have experienced debris in the last 2 months after hose changes.  but the engine had 2-3 hrs between run-up and flight tests.

He pulled the carb bowls and found very small debris in the left carb and the 'pressure jet was clogged"  He proceeded to clean it and we did several run-ups  He notice fuel coming out of the overflow so he also adjusted the float (was the engine flooding that side?)

We did several ground runups to 4500 rpm and no issues.  A different CFI (who is a mechanic) proceeded to take off at at pattern altitude we got the shutter again.  But it was only momentary 2x.  We circled the airport and climbed to get it back to their main shop.  

On the return, we were getting HIGH temps on the left side and still had boost issues.  We found a few other engine communication issues, GPS power and others on the test as well

What is going on here?  The carbs were rebuilt during the 5 yr hose replacement and they are doing a full inspection of the carbs and sounds like wastegate.   i just want to be educated enough to make sure nothing else is missing.

 

  • Re: 914 Engine Out and issues

    by » 3 weeks ago


    It might have a problem similar to what I endured this summer: an air leak in the supply side of the fuel system. In my case, it was due to a bad O-ring on the fuel tank selector shaft. Pull off the hose leading to the input of the mechanical fuel pump or better, tee into it. With some sort of restrictor, run an 1/8 hose to the bottom of a container and turn on the electric fuel pump. After some initial clearing, the flow of fuel should be essentially bubble-free and accumulate about 300 ml of fuel in 30 seconds.

    Air bubbles mixed with incoming fuel results in a bunch of odd symptoms, not inconsistent with what you describe.


  • Re: 914 Engine Out and issues

    by » 3 weeks ago


    I guess possible but i thought the 5 year hose included all fuel lines, etc.


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