Page 1 of 1

EXUP Cold/Hot operation

Posted: Sat Feb 12, 2005 2:45 pm
by 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>

Re: EXUP Cold/Hot operation

Posted: Sat Feb 12, 2005 10:05 pm
by thunderace
Your exup should start working as soon as you start the engine. <p></p><i></i>

Re: EXUP Cold/Hot operation

Posted: Sat Feb 12, 2005 10:13 pm
by 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>

Re: EXUP Cold/Hot operation

Posted: Sun Feb 13, 2005 8:11 am
by 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>

Re: EXUP Cold/Hot operation

Posted: Sun Feb 13, 2005 7:17 pm
by 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>

Re: EXUP Cold/Hot operation

Posted: Mon Feb 14, 2005 2:34 am
by 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>