GZ 250 Forums - View Single Post

**jonathan180iq** · 07-05-2013, 08:32 AM

I haven't had one of these things open in a long time so I'm usually just going by memory.

Check out Quimrider's thread about how to adjust the needle jet. It had some pretty good photos. From what I recall, there is a way to get things easily turned around when reinstalling and thus not allowing it to function properly.

Also, the seat of the diaphragm itself can get knocked out of the ringed groove fairly easily when you are reinstalling the black top cover. If it's even offset the least bit, it will pinch between the cover the carb and cause a slight air leak. You have to make sure that's all cleaned and sealed in order to go forward.

I say that 1/4-1/2 throttle is most affected by the mid range controller (the needle jet) because of general carb theory and I'll stand by that. It doesn't tell you exactly what the issue is, but it will at least tell you where to look.

-How does it respond when you put it in neutral and rev it into the 1/2 throttle range? Does it do the same? Have you guys tried the good old fashioned WD-40 leak test trick to see if the idle or throttle behaves differently when you spray different parts of the intake with it? - Also, check the "S" tube that connects the crank case to the bottom of the air box. And check that the drain tube coming form the bottom of the airbox is sealed off at the bottom.

07-05-2013, 08:32 AM	#4
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,995	Re: Bike dies when opening throttle I haven't had one of these things open in a long time so I'm usually just going by memory. Check out Quimrider's thread about how to adjust the needle jet. It had some pretty good photos. From what I recall, there is a way to get things easily turned around when reinstalling and thus not allowing it to function properly. Also, the seat of the diaphragm itself can get knocked out of the ringed groove fairly easily when you are reinstalling the black top cover. If it's even offset the least bit, it will pinch between the cover the carb and cause a slight air leak. You have to make sure that's all cleaned and sealed in order to go forward. I say that 1/4-1/2 throttle is most affected by the mid range controller (the needle jet) because of general carb theory and I'll stand by that. It doesn't tell you exactly what the issue is, but it will at least tell you where to look. -How does it respond when you put it in neutral and rev it into the 1/2 throttle range? Does it do the same? Have you guys tried the good old fashioned WD-40 leak test trick to see if the idle or throttle behaves differently when you spray different parts of the intake with it? - Also, check the "S" tube that connects the crank case to the bottom of the air box. And check that the drain tube coming form the bottom of the airbox is sealed off at the bottom.
	0