I have a 2007 drz 400 sm with less than 4000 miles. Im not sure if this is a problem with all drz's or if its even a problem at all but i was wondering if anyone could help me out.

When the bike is idling, if i rev the throttle pretty fast it will shut off. This will only happen if I rev it from idle. If i turn it higher (kind of uncomfortably high) and then rev it theres no problem.  Is my idle too low? it doesnt sound/feel low.

Ive only ridden 2 strokes before (02' CR250 , CR 125) and they are very responsive from idle. I could rev them as fast as I can and they never shut off. This doesnt really affect normal take offs or even racing takeoff's because I rev i initially rev it anyway. It just seems weird to me that I can make the bike shut off by punching the gas. Love my drz but this seems strange.

Can someone tell me if this is just a  4-stroke thing? Any help?

Might want to ask this in the DRZ-400 subforum...

is the bike stock?  stock carb?  Did it sit for any length of time?

I keep my idle between 1800-2000rpms on my bike.  There is a pilot circuit which is from idle to 1/4 throttle.  If your bike sat and the carb has some gunk built up in it this jet could be clogged partially causing your issues.  What does it feel like when you ride it?

You will certainly get more responses in the drz forum.

Are you bliping the throttle, quick fast turn from idle? Probably shouldn't do that as much with a 4t. There is a lot more and heavier rotational mass in a 4t that has to get going really fast. If I crack the throttle on mine from a dead idle it will stall also. Roll the throttle, no bliping it is not a 2t.

4 stokes have that bog...... sounds like the air screw may need to be tweaked a little.

Edited by lumpy790, 10 May 2012 - 06:15 AM.

lumpy790, on 10 May 2012 - 06:15 AM, said:

There isnt an air screw on the stock drz bsr36 carb.  If its never been touched there is a brass plug in the bottom that will let him get to the fuel screw for the pilot circuit.  Stock these bikes are jetted very lean and have more issues with surging rather than bogging.  Also the stock carb is CV so even if he cracks the throttle wide open the slide wont raise with out the engine rpms raising unlike an FCR carb that comes on every other 4t.

Having said all that i still don't understand why the OP is free revving the bike in idle

shift1313, on 10 May 2012 - 09:08 AM, said:

True ....and that plug can be tricky to get out... and one oops and the needle tip gets trashed.

i had that exact problem with my drzsm but i just turned the idle up slightly and it fixed the problem so i think very easy fix

I just went through a similar problem with my 06 SM where it would idle but as soon as I started opening the throttle it would die. As it had been sitting for 2 months without running I suspected some kind of blockage in the carb and turned out the main jet was partially blocked. Once I cleared that she ran fine.

Hope this helps
Wayne

mine too I'm not convinced its the jetting. cleaned out carb,though it didn't seem dirty installed new pilot readjusted fuel screw and still does it