RE: rich or lean gas?
Jason,
Gas engines do not work like that so pinching the line will not work because they use so little fuel you may have to hold that line for several minutes. On the Brison 3.2 do not make the adjustments while it is running, you will be way too close to the prop. Once you get the needles set unless the weather really changes allot, you will not need to touch them again. It may tke 20 minutes but its well worth it. If you bought this engine new, Gary usually has a tag on it that tells you what prop he tested it with and what rpm he got. The needles will most likely be set already.
If it's used then you may have to adjust it yourself. It's really not hard. Remeber one thing, you will be making very small adjustments. 1/8th fown to 1/16th turns at a time where most nitro engines you make 1/4 turn or more adjustments.
Here is something I found that will help you.
Open both needles 2 turns
Start engine
Lean out high speed needle for max rpm, then back off about 200 rpm
Slowly lean low needle and try transition
Do it until no transition
Open low slightly until transition is good
Re set high, leave slightly rich
FLY............................
Applies to ALL gassers, Walbro, Tillotson, Zama, Del Orto, Bing, etc.....................
If the ‘H’ needle is too lean, it may cause the following three symptoms.
1. Engine stops at full throttle.
2. Engine hesitates when accelerated rapidly.
3. The engine will not come up to full RPM at full throttle.
If the ‘H’ needle is too rich, it may cause insufficient RPM at full throttle. This
causes carbon buildup on the spark plug.
If the ‘L’ needle is too lean, it may cause the following three symptoms:
1. The engine hesitates when accelerated rapidly.
2. The RPM increases at idling.
3. The engine stops when the throttle is moved from high to low.
If the ‘L’ needle is too rich, the idle may be unstable.
The position of the ‘H’ needle will vary according to air temperature and
field elevation.
These are generic instructions but they have served me very well for my Brison, Zenoah and DA engines
You also have one of the better 50cc engines around