Brison 4.2 loading up on the down lines
 

Good Day To All,

I am having troubles with a Brison 4.2 loading up on the extended down lines if I have it throttled right back. Engine seems to transition very well on the ground but wants to go rich in the air at the lower throttle settings.. works well at full power. I have the pump diaphram vented to the inside of the fuse. The engine is installed in a Lanier 30% edge so the carb is close the cowling.. I only have 12 flights on this airplane I also noticed if you turn sharp at a lower power setting it also seems to hesitate a bit.

Thanks in advance for the input..

Riverdancer

RE: Brison 4.2 loading up on the down lines
 

I had a very similar problem to yours with the Sachs-Dolmar 4.2 in my Bücker Jungmeister. The carb was very close to the cowl. I fixed the problem by cutting a hole in the cowl. Sure hated to do it but it really made the engine run better.

Ken

RE: Brison 4.2 loading up on the down lines
 

Thanks for you effort Big Bird.. I have cut away the cowling around the carb and it doesn't even look to bad. If the weather ever cooperates I will get a chance to try it.. I will keep you posted.

Thanks again,

Riverdancer

RE: Brison 4.2 loading up on the down lines
 

Hey there Big Bird,

Just a quick update.. I cut away the cowling and the engine works much better..pretty good on the down lines but I still have troubles if I make a sharp pull up, it wants to go rich.. hasn't quite yet wich is nice.. but I still don't quite trust it 100%

Thanks again for your help

Take Care

Riverdancer

RE: Brison 4.2 loading up on the down lines
 

Sure glad to hear that it works much better. I assume that the sharp pull up is near idle. You might try leaning the idle about 1/8 turn and see if there is an improvement.

Ken

RE: Brison 4.2 loading up on the down lines
 

Hello Big Bird,

Thanks, I am about as lean as I can be on the low end.. it will die in the transition if I go any more.. I blocked off the scale inlets and that has cured the pull up isses but the engine is still ragged at the lower throttle settings.

Thanks agian and enyoy your day..