DRZ400S performance mod recommendations

[BellevegasB]

Hello all,
I'm a relative newbie, bought my DRZ400S about 5 months ago. Well, I'm comfortable enough on the bike to start looking for performance upgrades. I want the bike faster in the low to mid range. Much faster, actually! Top end doesn't matter too much. I do ride it on the street, but never on the highway, so I don't need a super high top end. I would however like to be able to go 65 to 70 when needed. So, supposing I set a budget of $500, what do you guys recommend? What mods offer the biggest bang for the buck? And should I possibly think about just putting all my cash into a big bore kit? Any info is appreciated.

 

[azcab]

For about $20 in jets, you can rejet, pull the airbox snorkel and open up the stock exhaust. You will notice an immediate boost in low and mid range. If you want more, spend $300 on a pipe and silencer, and you will see further gains.

 

[DEANSFASTWAY]

Big bore kit and hot cam are the most needed things or are what will make the most difference and thats where the best value will be in my opinion .JMHO

 

[MelloYello]

I think azcab is pointing you in the right direction. Rejetting and pulling the snorkel will make a noticeable difference. Adding an aftermarket exhaust will net good results also. If you have your stock sprockets (I believe 15/44?), you can go down to a 14 tooth front and that will give you a little more boost on the bottom. You will still be able to go over 70. Good luck.

 

[DEANSFASTWAY]

Shift into high gear and assume the wind tuck position.

 

[Vytas]

I have already put a 14 tooth CS sprocket on mine and it made a difference.  Next I am going to modify the air box and rejet.  These the cheapest mods to make.  Next will be a larger rear sprocket and then maybe an exhaust.  Do a search on the DRZ and you will find some good info.  Good luck.

 

[mdkuder]

Check out the following:
http://drz.info/drz/
http://www.thumpertalk.com

 

[Pvt Joker]

Everything you want to accomplish can be done for less than a hundred dollars.

The jets are less than $10 if you buy them from a motorcycle shop. Make sure they're the Mikuni or buy them both from Baja Designs for around $15. Cut the 3x3 square in the airbox. Go down one tooth on the countershaft sprocket and up as many as you're comfortable with on the rear. I preferred 14/50 gearing. It could easily do 70 and felt like a torque breathing monster.

I'd strongly suggest doing these two things and hanging on to the rest of your money for a while. Unless you're trying to shave several pounds, the exhaust mods or a new exhaust, while louder, will only have a neglible effect.

For a hundred bucks, you could do all that and have enough left over to get a DRN t-shirt.

 

[Wolf]

I just modified my DRZe. I rejetted and opened up the Exhaust and airbox. Nice. But I was looking for more.
I found that removing the coast enrichener and rejetting accordingly (EMM needle, 38/ 162/ 70) made this thing really nice. More than I ever expected. Find info on the above mentione web site. Its worth the effort! You will be suprised!

 

[beefking]

The "s" version has a Mukini CV carb, no coast enricher.

All the above is pretty much right on...a Dynojet kit and jetting (DJ jets are no good for opened up airbox) will liven things up ALOT and only increase noise by a very small amount. Cutting a hole in the left side cover works even better than just cutting the top out, and you would need some mesh over the hole.

If you can tolerate noise drill out the center piece on the stock endcap with a 1-3/8" wholesaw bit (bimetal bit). Gearing too, the stock 15-44 is not necessary unless you ride alot of fast roads/highway.

All of what i mentioned above would cost about $60 (dj kit is around 50). If you want even more low-mid range i would just go with a thumper-racing.net 440 kit. You can have it installed (just in the motor, not complete assembly) for less than $400. I'm getting ready to do this my self, aiming to have it done by february. :)

 

[Vytas]

I have already ordered the jet kit through BajaDesigns, $17 w/shipping.  Just finished cutting open the airbox, the Dremel tool with a steel cutting wheel did the job very nice.  I will post again after I have installed the jet to let you know how things are running.

 

[Wolf]

Sorry, I did not know that the S model had a different set up.