Page 1 of 1
carb tuning
Posted: Fri Jul 24, 2009 8:11 pm
by nozzlegoblin
Can anyone help me. I just got a 1981 Yamaha xj750 seca. We had to pull the carbs and totally clean them out to get it to start. It sat in a garage for 8 months. We stuffed them back in and it runs but something's not right. I am mechanically inclined, and I'm a fast learner, but I am inexperienced about this. I have no clue. I've been riding it because I can't help it, I love it, but I fear I'm doing some damage. BTW, I'm pretty broke or it would be in the shop right now. Thanks in advance if anyone is kind enough to give me a clue.
Trevor
Posted: Fri Jul 24, 2009 11:34 pm
by cHAosjiHAd
Have you sync'd the carbs? Can you describe what's 'not right'?
Posted: Sat Jul 25, 2009 2:40 am
by Wrider
You may need to "bench sync" the carbs if you don't have a vacuum gauge to do it on the bike. What you do is pull the carbs again (yeah I know, what a PITA.) Then when they're on the bench adjust all of the butterflies so that they're equal to the one the idle is set off of. Meaning so that they all have the same amount of opening. (should be very small.) Also, make sure the fuel/air mix screws are equal on all of them, although you may need to let more fuel into the center cylinders because of the heat differences.
Homemade sync tool
Posted: Sat Jul 25, 2009 10:54 am
by cHAosjiHAd
Here's an easy tool you can make to sync your carbs, courtesy of Mr. Marty Ignatzito.
http://www.650ccnd.com/mano.htm
[EDIT] I didn't realize that Skier already had a similar sticky here...
viewtopic.php?t=746
Posted: Sat Jul 25, 2009 1:09 pm
by fireguzzi
What are the symptoms?
Posted: Mon Jul 27, 2009 3:28 pm
by Social Distortion
ok...............
\we wanna help\us old timers that know carbs cant wait to turn and manipulate and do all the good things that we love/hate bout carbs