Why are my mixture screws open on my 750?
First, it is apparent that not all the 750’s come from the factory with the mixture screws turned out to 2 1/4 turns open as the Service Manual indicates they should be. This would seem to be right in line with many owners reporting popping on decel when the bike is right off the showroom floor! Some have even found one of them closed entirely!
What happens when you loosen the fuel mixture screw?
1 Loosening the screw strengthens the air and fuel mixture and increases the amount of fuel flowing to the engine. 2 Loosening the screw is also called making the fuel mixture richer, which increases the RPMs at which the engine idles. 3 Running a rich fuel mixture causes the engine to run with more fuel than it needs to operate efficiently. …
Can a bike engine be damaged by adjusting the screws?
Don’t worry, you are not going to harm the engine by allowing to it exhaust more air or by giving it more fuel. You also will not void your bikes warranty by punching and drilling the exhaust. You’ll only void the warranty on the exhaust. Adjusting the screws will not void the warranty.
How do you get a brass air mixture screw out of a carb?
When it gets tight, get a pair of pliers and grab hold of the screw (vice-grips would work good here) and carefully tug on the screw. Eventually the screw with the plug attached to it will pop out. Look into the hole the plug came out of. There you will see the holy grail, the brass AIR MIXTURE SCREW! Repeat the steps above on the right side carb.
First, it is apparent that not all the 750’s come from the factory with the mixture screws turned out to 2 1/4 turns open as the Service Manual indicates they should be. This would seem to be right in line with many owners reporting popping on decel when the bike is right off the showroom floor! Some have even found one of them closed entirely!
Don’t worry, you are not going to harm the engine by allowing to it exhaust more air or by giving it more fuel. You also will not void your bikes warranty by punching and drilling the exhaust. You’ll only void the warranty on the exhaust. Adjusting the screws will not void the warranty.
1 Loosening the screw strengthens the air and fuel mixture and increases the amount of fuel flowing to the engine. 2 Loosening the screw is also called making the fuel mixture richer, which increases the RPMs at which the engine idles. 3 Running a rich fuel mixture causes the engine to run with more fuel than it needs to operate efficiently.
What’s the best way to adjust the mixture screws?
If the bike has not been previously warmed up, let it idle until it is warmed up. Once the engine is warmed up, start with the left mixture screw (rear cylinder) and slowly turn it closed until the rpm’s drop and the idle begins to falter.