99- carb theory 101 (running poorly)
Posted June 19, 2006 - 02:20 PM
Second issue, this has been a problem since I bought it and still have found the cause, should be fairly easy for a carb guru type to nail the issue. It has a problem where if you shake the bike hard smaller hard bumps, the bike stutters and if severe enough will die. It´s worse when you are going up an incline, incline and bumps equals a stalled bike. I have adjusted the float a bit to make for less gas in the bowl, and I think that helped but it´s getting pretty problematic cuz I'm riding harder. So, I think I´m smelling gas when it quits... so were likely talking about a flooding condition rather than a starving condition right? Does that equate with the mechanical arrangement of the carburetor in relationship to the "incline" problem? Even though my float valve needle is new (the seat is old), seems I'm looking at either needle seat leakage or a still improper float level? Could the seal around the OUTSIDE of the valve seat (where joins the carb body) be bad? Sorry this is so wordy, but I'm looking to understand this problem as well as I can before I order parts. Basically I´m wanting to at least confirm that this is a problem of EXCESS gas rather than a momentary starvation problem.
Posted June 19, 2006 - 02:31 PM
When it comes to solving ANY jetting issue, the carb must be disassembled for a cleaning of biblical proportions.
On our carbs, the air jets have been known to plug. This can be caused by excessive oil in the air filter, or not letting the air filter oil "set" prior to firing off your engine. The air jets are found under the air horn on the airbox end of the carb.
On my 99, I removed the entire air cut valve assemby and sealed off the unused ports. I changed the air jets (just the MAJ I think) to the YZF.
Also, you can improve your accelerator pump performance by installing a set screw under the diaphragm to limit stroke time of the pump.
According to Factory Yamaha, the optimum stroke is ~ 0.5 seconds. My 99 was 3.5 seconds!
I replied to one TT'er that posted in the jetting forum about installing our FCR onto his DRZ. Do a search there, under my user name.
Any other Q's, feel free to PM me!
Posted June 19, 2006 - 03:52 PM
Posted June 19, 2006 - 05:12 PM
Yes, I know... one thing at a time... I can never seem to do that
Posted June 19, 2006 - 05:47 PM
Although i am probably wrong like i seem to always be.
Posted June 19, 2006 - 06:20 PM
Am I right huh huh? Probably not... really though... I get didly when I change the fuel screw position... nada, SOMETHING must be off, no?
Posted June 19, 2006 - 07:11 PM
Posted June 20, 2006 - 11:49 AM