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Thoughts on DJ kitted CV Carb jetting

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I finally seem to have my DJ kitted CV carb dialed for my elevation (7,000 feet and up riding areas). This is my CV carb jetting story.

I believe the DJ kit (at least the original ones) have a very aggressive taper on the needle which creates a rich condition at low rpm and small throttle openings and the soft DJ spring, which otherwise provides excellent response, aggravates the problem. Perhaps the Yosh pipe and Hotcams intake hit the carb with a sharper signal and draw more fuel than stock too. Anyway, my bike has always had a rich condition at minute throttle openings which was aggravated when I moved to Colorado and it's high elevations.

To test for this on your bike, just barely turn your throttle from idle and listen to the engine. Mine would labor a bit and then clean up as the throttle was twisted further. As minor as this seemed, it magnified itself and managed to drive me nuts on the trail. I do lots of technical trails and the bike would "load up" after going down long hills on closed throttle and it always stuttered a bit when coming off low rpm while zig zagging around trees and such in 2nd gear.

Well, my problem is finally solved :ride: I had been running the #1 clip position, with the nylon thingie and thick washer under the clip. The thin washer was over the clip. I took out the thick washer and put the thin one in it's place under the clip, lowering the needle another half step from the #1 (top) position. Fired the bike up, instead of being rich, it was a bit surgy and lean at small throttle openings while warming up in my driveway at 5,400 feet, but the engine was not fully warm either. Still, I imagine it is a bit lean at my home's elevation, but I only ride my DRZ on higher elevation mountain trails, so it went on the trailer and off I went.

Took the bike up to my 7K foot elevation riding area and holy crap. The fueling is perfect. The thing pulls crisp from just off idle now and charges clean with progresive throttle from low rpms on into the midrange. No more loading up after going down a long descent and picture perfect crisp and responsive lift the front end at will trail power. I am running a 132 main and stock 22.5 pilot with an adjustable screw by the way. I was shocked at the difference this seemingly small change made. The engine is very clean and responsive to small throttle openings now, which rocks when picking my way through, ah, rocks! I also had to turn my pilot screw out to 2.5 turns. It still pops some on decel, but before it would have drowned at that setting. Good enough I say.

Given the way the thing runs now and the gnarly trails I ride, I am pretty much forgetting about changing out the CV carb. While losing top end power, it is amazing how sharp and responsive a tightly set up CV can be at low and midrange rpm on the trail. Most of my FCR budget went to the rear shock anyway! See my ride report on Eddie's wonderful work under another post on that :thumbsup:

My settings are unusually lean due to my elevation, but the same principle applies. If your DJ kitted CV carbed S has that rich hesitation, try moving your needle down (leaner) and consider going to a half setting.

All you out of town DRZer's who are coming to CO for the rally, better get your jetting hats on, especially if you want to do the 7K elevation Rampart Range mountain trail ride :applause:

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Interesting. The updated less tapered needle wouldn't be so finicky about small throttle openings and extended closed throttle decel. The bike has always run good from about 1/4 throttle on, it was just progressively more fuzzy at openings below that. No more.

Anyway, the thing is working so darn well now I am less interested in messing with it and more interested in riding it some more :thumbsup:

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