My Brison 3.2 just started to do this. If I go from low idle (1950 rpm) to WOT quickly, it'll sputter and quit. If I advance the throttle slower it runs fine. Been everywhere on adjusting the needles. I've gone real rich on low, then leaning the high. I've gone rich on the low and left the high rich, but then it burbles bad. Then when I lean the top back out to get it not to burble, it quits under fast transition. No good. I seem to end up in the same place every time. Checked the screen, it's clean. Fuel system is clean. Timing's right on. Sometimes even when the engine is hot, it still needs to be choked to get it started. It also doesn't seem to draw fuel well on cold start-up. I always have to prime with a shot to the carb. Thanks for any help.

If it isn't picking up fuel well when starting you might have too lean of a low end. Remember to get the high set before tuning the low end.

If all else fails, put a carb kit in it. Made a world of difference in my three year old Brison. You can get the kit at most small engine repair shops.

I agree with Ryan, you will have to riched the low speed needle. I read in a Quadra manual a while ago, that the low speed neeedle feeds the mixture until about 1/2 throttle unitl the high speed needle comes into play.

I was out on Tuesday night flying the GP Patty with the Brison 3.2, I was rich, took four flights unitl I got the 3.2 running where I wanted it, a few clicks on the needles until it got there, I also check the spark plug tip color to see to ensure I am not overlean.
good luck - ken

Yep, as everyone has said. it is rich. If you get the transistion right and it is rich in the mid range, then it is too rich but should not be problem. Just do a click or 1/16 turn at a time and you should be fine. Make sure engine is HOT!

Clean the intake screen und the carb cover. It's under the cover with 1 screw.

Got a Brison 3.2 w/electronic advance and just tuned it yesterday. Used the advice from [link=http://www.rcuniverse.com/forum/m_3019271/tm.htm] HERE[/link]. Worked out perfectly. Was a bit tricky though. Did it with the motor running. With someone holding the plane, I straddled it behind the motor while taching it and making adjustments. You HAVE to be very careful though as the carb is only like 2 inches behind the prop. To make adjustments a bit easier I cut 2 pieces of fuel line and put them on the low and high needles to make turning them possible. Without it it was next to impossible to get a grip on the needles because of the vibration. Besides, I didn't want to worry more about trying to dial in the mixture than where my fingers were. The tubing made it possible. But depending on the size of your hands and fingers, this may not be a feasable way to go about it. I have fairly small hands and fingers so it worked for me while still being able to stay safely away from the prop. If you do it this way...with this motor....JUST BE CAREFULL! With that being said....throttle through the entire RPM range is spot on, with no 4 stroking anywhere......and throttle response is instant. The true test is how it will actually run while airborn. One thing that I did do to try to alleviate differences between running on the ground and while in flight, was to remove the carb diaphram cover and solder a piece of brass tube to it and ran a piece of fuel line from it into the fuse to minimize running changes due to differences in air pressure. We'll see


Cap

Thanks to all. She's running good again. I also brought the idle up to 2200. Readjusting the carb as recommended above works great. Thanks again.

I wonder if the tubing idea will work with a screw driver.
I may try that the next time I adjust the engine.

Don't see why not.