How does EXUP valve work?
How does EXUP valve work?
This is a system that employs a variable EXUP valve in the muffler that can change the configuration of the exhaust duct in a way that controls fluctuations in exhaust pressure at the moments of overlap between the intake and exhaust valves in order to improve intake efficiency, boost power output and improve fuel …
What is an EXUP valve?
The EXUP system was a four-stroke power valve system, placed in the bottom-end of the exhaust’s downpipes to fool the pipe into thinking it was the best ‘length’ for both mid-range and high-rpm operation. You see, exhaust systems are a compromise.
What is the purpose of a servo buddy?
Servo Buddy allows for a complete elimination of the servo motor, valve & cables. Utilizing the Servo Buddy improves reliability by eliminating issues when the factory servo motor fails.
Do 4 strokes have a power valve?
A four-stroke power valve is a device fitted to four-stroke engines that constantly adjusts the internal diameter of the exhaust system to better suit the speed of the engine. The valve goes from being almost fully closed at idle speed, through to fully open at higher engine speeds.
How does a power valve work?
The power valve is a movable flap located on the cylinder exhaust port of a two-stroke engine – where burnt gasses are flushed out of the cylinder. This helps the engine generate torque at low speeds. As revs build, the flap gradually opens, expanding the size of the exhaust outlet for greater top-end power.
What does the set valve do on a GSXR?
It is designed to help low to mid range torque.
How does a servo buddy work?
It works by electrically mimicking the working exhaust servo so the computer thinks all is well with the exhaust circuit preventing the FI light from coming on due to exhaust faults while still keeping the lights other functionality to warn you if anything else is wrong with the bike!
What is a motorcycle set valve?
Essentially, valves act as the doors to the combustion chamber, allowing the fresh mix to flow in during the intake stroke, sealing the chamber during the compression and power strokes, and providing an exit for the spent gas during the exhaust stroke. …
How do you hold an EXUP valve in place?
Hold the pulley in place by putting a punch or suitable sized rod through the pulley forks into the hole in the EXUP end plate. Undo the 8mm bolt and remove the bolt and washer. Note the orientation of the pulley on the spindle before removing it. Be ready to catch the spring and large flat washer immediately behind the pulley.
Where is the exhaust ultimate power valve located?
The Exhaust Ultimate Power Valve (EXUP) alters the back pressure in the exhaust system at various revs. It consists of a gate valve in the EXUP housing, the cast exhaust section immediately behind the headers and below the engine.
How do you fix an EXUP valve on a Fazer?
Refit the valve into the valve housing locating the spindle in the bush shown in Photo 6. Refit the end plate bolts with the cable holder in the correct position. Apply a generous coat of copper grease to the allen bolts beforehand. Tighten the bolts to the correct torque. All the bolts in the EXUP system should be torqued to 10Nm.
Why is my EXUP valve not working properly?
Problems with the valve operation are indicated by a 7k rpm fault code on the tacho. Usually this means that the cables are too tight, causing the servo motor to bind, or that the valve itself is sticking or has seized in its housing. Occasionally, the problem may be with the servo motor itself, but this is rare.
Hold the pulley in place by putting a punch or suitable sized rod through the pulley forks into the hole in the EXUP end plate. Undo the 8mm bolt and remove the bolt and washer. Note the orientation of the pulley on the spindle before removing it. Be ready to catch the spring and large flat washer immediately behind the pulley.
The Exhaust Ultimate Power Valve (EXUP) alters the back pressure in the exhaust system at various revs. It consists of a gate valve in the EXUP housing, the cast exhaust section immediately behind the headers and below the engine.
What kind of bike does EXUP valve work on?
The EXUP valve worked brilliantly and was used on a wide-range of Yamaha machines. Bikes such as the FZR250R and FZR400RRs used the valve – as small-capacity machines would get a useful mid-range hike from the system.
When did the EXUP valve Classic come out?
The ‘foxeye’ FZR600R (4JH) didn’t have it, although 1993’s YZF750 similar-looking did: Yamaha claimed that the system wasn’t needed on the newer 599cc motor and that it would have added around £600 on top of the machine’s price new in 1994 of £6299…
