2001 DRZ 400 need help????

[Poolman]

My DRZ is stock except for a Yoshimura titanium pipe. Runs excellent except it has an annoying bog from idle to 1/4 throttle. If the throttle is twisted even slightly fast, the bike bogs real bad or even stalls. Any ideas or suggestions?

 

[biglou]

Ah, the old off-idle bog.

I had the same set-up you do, and never had too much trouble with it. I ran a 168 main jet and had the pilot screw at 1.5 out. I found that if the rev's were kept up a bit, the problem was less severe or non-existent. I would use the engine braking when slowing down to keep the RPM's above a dead idle. When accelerating, I could pretty much whack the throttle full open and get that freight train, tractor power with no problem. Mine would cough when setting on the stand, but never under load. This is a tricky problem to fix, I wish I had a definitive answer. I am assuming that you are running super unleaded pump gas. I ran nothing but Amoco Ultimate. The general consensus was to open the pilot screw incrementally to help with this. Short of that, playing with the pilot jet and other brass in the carb is the next step. Not an easy task on the DRZ, especially if you have the E-start as the starter is packed in tight under the carb. Do a search looking in this forum (Thumper Central). I know there are a few posts concerning the YZF's here, but don't remember seeing too many specific to the DRZ. If you don't get the answers you're looking for here, try www.thumpertalk.com and go to their DRZ forum. That topic is always present there. Do a search and you'll get tons of threads on the subject.
Good luck!

This just occurred to me: You mentioned that your bike is stock with the exception of the pipe. Have you rejetted or pulled the lid off the airbox? If not, do it! Pull the seat and then take the top of the airbox off (It's rubber, with a snorkle. No tools required). And, rejet the main to a 168. Start with the pilot screw at 1.5 out and work out from there if you still have problems.

Note: Test for the bog while riding, not on the stand. It'll still cough a bit on the stand, as I mentioned above, but behave much more predictably while under load.