EXUP Cold/Hot operation

[Monsterbishy]

Would I be right in saying that the exup valve on my YZF750R doesn't operate fully until the engine has reached a certain temperature? <br><br>I'm wondering this since I was leaving work yesterday, bike had been running for 3-4 minutes, when I gave her a bit of stick at a set of lights, felt quite sad until about 9k when all the power came in at once and damn near pulled me off the arse end of the bike, after that she pulled hard in first from every set of lights after that.<br><br>Or should I be checking my exup for a fault? <p></p><i></i>

[thunderace]

Your exup should start working as soon as you start the engine. <p></p><i></i>

[djalbin]

The EXUP valve is opened/closed by the EXUP servo motor that gets its signals from the digital ignitor unit. The EXUP valve is opened/closed based on engine RPM. <br>Don <p></p><i></i>

[dragracer1951]

first thing I would do is pull the plugs and see if it's running rich and it cleared it's throat.....<br>Jim <p></p><i></i>

[Nbot]

sounds like it was bogged? exup=rpm's....read about it <!--EZCODE LINK START--><a href="http://ymedc.introweb.nl/en/archive/cla ... <!--EZCODE LINK END--><br><br>You might like this too...<!--EZCODE LINK START--><a href="http://ymedc.introweb.nl/en/archive/cla ... <!--EZCODE LINK END--> <p><!--EZCODE FONT START--><span style="color:orange;font-family:century gothic;font-size:medium;">Nbot</span><!--EZCODE FONT END--><br><!--EZCODE FONT START--><span style="color:green;font-family:century gothic;font-size:small;">'94 Fizzer Litre</span><!--EZCODE FONT END--><br><!--EZCODE FONT START--><span style="color:orange;font-size:small;">This is your sig on drugs....</span><!--EZCODE FONT END--></p><i></i>

[Monsterbishy]

I have a sneaky feeling it was actually a surface-related problem, I haven't been able to replicate the effect since, so I'm guessing that I must have hit a bump, causing me to twitch the throttle right open, or momentarily bounce the rear wheel off the ground. <p></p><i></i>