Which is better FMF or Pro Circuit?
FMF: The Pro Circuit has a little more throttle to rear wheel connection down on low end, but the FMF pulls stronger through the mid range. Up on top end both seem on par with each other and of course both have less over-rev than the stock muffler.
Does Akrapovic make 2 stroke exhaust?
KTM Akrapovic 2-Stroke Slip-On Exhaust.
Which is better FMF or Yoshimura?
The FMF system is louder than the Yoshimura or Akrapovic systems by quite a bit even with the inserts in, but keeps that racey deeper sound. The good news is that the muffler packing has lasted longer than I expected. We are over the 12 hour mark and the 4.1’s still sound good.
What does a 2 stroke silencer do?
The 2-stroke exhaust system uses an expansion chamber – the prominent bulge in the exhaust pipe – to increase the engine’s horsepower. In short, the expansion chamber creates a pump, by using the momentum and pressure of the exhaust gases, and squeezes more air and fuel into the cylinder during the intake stroke.
Why are 2 stroke exhausts so big?
That bulge is called an expansion chamber, and it is used to increase the horsepower of the engine (see this page for a photo). This technique only works on two-stroke engines, which is why you see it on a lot of dirt bikes but not on street bikes.
Does a 2 stroke need a muffler?
2-strokes run fine without mufflers, if your muffler pipe is an expansion chamber you might notice a low to medium power loss, but you should be fine. The right length pipe can actually help a two stroke. Yes you can run a straight pipe. Without the muffler, the bike will probably run lean.
Will a 2 stroke engine run without an exhaust?
Can you run a 2-stroke without an exhaust? – Quora. All combustion engines will produce exhaust gas while operating, which must be evacuated from the combustion chamber to make room for fresh fuel-air mixture. So, in that sense, you cannot run any engine without an exhaust.
Does 2 stroke need back pressure?
lower back pressure will mess with the pipe and the way it functions, a 2stroke pipe is made to work with some pressure in order to push the exhaust waves back into the motor thus filling the cyl with new fuel and also burning the unburned fuel in the exhaust.
Can a 2 stroke backfire?
Improper ignition timing can allow the engine to backfire. On a two stroke the reeds generally block it ends up sounding more like an “umph” than a bang. A backfire out the exhaust is generally the result of the engine failing to ignite the air/fuel mixture for several revolutions.
What makes a 2 stroke pop?
Deceleration surges (pipe-bangs) in 2-stroke engines, and how to cure them with the PowerCDI. Instead, it is a normal but very intense combustion ignited by the spark plug, which increases the engine speed 500-700 RPM in a single engine revolution. This is perceived as a sudden surge, during engine braking.
Why would a 2 stroke backfire?
On a two stroke the reeds generally block it ends up sounding more like an “umph” than a bang. A backfire out the exhaust is generally the result of the engine failing to ignite the air/fuel mixture for several revolutions. The air/fuel mixture passes through, filling the exhaust system with a burnable mixture.
Why do outboards backfire?
If it is backfiring and spitting back through the carb it may be what is known as a lean sneeze. This is due to a slightly lean mixture due to dirty jets, incorrect mixture adjustment or low fuel level on the float chamber, in turn due to flow restriction or faulty pump.
What is a lean sneeze?
Outboard motor sneezing is an audible result of a lean fuel mixture resulting from problems in the carburetor. Described variably as a sneeze, cough or stutter, an outboard motor or any engine will lose its ability to run smoothly if it does not receive enough fuel.
How do you know if your outboard is running lean?
Usually when people talk about motors running lean, they are referring to the fuel/air ratio. Signs that the fuel/air ratio is too lean are things like; backfires at high throttle settings, hesitation when the throttle is opened, or the motor actually slowing down the more you open the throttle.
Should I leave my outboard motor up or down?
Should I leave my engine up or down? Simply put, if you are leaving the boat in the water, leave it in the up position to avoid growth. If you are leaving it out of the water, trim it down to drain the water and protect the Power Tilt and Trim seals from the sun.
Is it bad to run an outboard engine at full throttle?
Does this mean an engine should never run at wide-open throttle (WOT)? Absolutely not. Modern engines are designed to handle WOT. Also, during break-in going to WOT, as prescribed by the owner’s manual, is necessary to properly seat the pistons’ rings.
How low should my outboard sit in the water?
A boat rigger’s rule of thumb is that the motor can be raised one inch for each eight to 10 inches of distance between the transom and prop. As the prop moves further aft, it’s also likely to be in cleaner, “harder” water, and be more efficient.
Can outboard motor run out of water?
You can run an outboard for a very short time out of water, but the impeller is running dry and will shred very rapidly.