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DRZ400S rich?

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Here is what I have and the symptoms. Think it might be a little rich but not positive.

JD kit-blue needle on 3rd clip.

155 main

25 pilot

3x3 mod

0-3000 ft

cool temps

Full Yosh RS2

K&N filter

It gets up to speed fast but seems like it won't rev out all the way. Top speed I was able to get to was 82 on stock S gearing. I had the needle on the 4th clip and it was worse than 3rd. Is my main to large?

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what altitude are you testing at?

if you think its rich,take the air boox door off and ride.if its better you need a leaner main jet.

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Testing at around 200'. I'll give it a shot tomorrow without the door.

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When I had the needle on the 4th clip it would studder at about 3/4 idle. Raising it to the 3rd clip elimitated that so I figured I was rich. Maybe was rich in the middle and lean on top? I'll do some testing tomorrow, just didn't want to be bouncing all over and getting nowhere.

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Ok, definitely need some more help. I did the air box door test with the 155 main and it ran a little worse without the door but same top speed. Here is where I'm at.

Same needle and pilot as above. About 99% sure the needle and washers are in correctly. Runs great up to about 3/4 throttle.

155 main

door on-80 mph top speed

door off- 80 mph top speed, felt weaker but got to the same speed

160 main

door on-81 mph top speed, didn't feel as strong as the 155 on top but was faster.

door off- cut out badly, didn't get anywhere near 80.

150 main

door on-cut out badly, didn't get anywhere near 80.

door off- cut out badly, didn't get anywhere near 80.

So this seems like I'm still lean on top but 160 seems pretty big already right?

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are you sure you are chaning the main jet and not the starter jet?

make sure the slide is fully lifting.the slide spring can get cocked and limit the slide.

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Yep, changing the main. Pulled out a 142.5 which I think was stock.

I pulled everything off and checked it all again but still having the same issues. The slide seems to be opening all the way and I checked the needle washers again. Seems to run best with the 155 but I was expecting more out of it.

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are you sure you are not hitting the rev limiter?

what gearing does the bike have?

I thought about that last night. I'm new to the DRZ so that is totally possible. It is stock gearing so 15/44. I verified the 44 stamped in and counted 15 so I'm pretty sure that is right. I used a gearing calculator and figured that put me around 7500 rpm. It pulls strong to that point and then is just flat with the 155 and bounces with the 160. 150 was definetly lean. Does a K&N let a lot more air through than a standard foam filter?

I put it away for today. It is typical Oregon weather today so my back road testing area is wet and windy. Got blown completely across the road so I figured I better quit while I'm alive.

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I think I'm heading the right way. Popped in a 165 and it got me up to 87mph and was still pulling when I backed off.

Last question.......the bike shop only had the 165 in the "large" jet. The head is larger than the stock and JD jets. It fits just fine but is that 165 the same as the correct(smaller head) 165? Ok to run it or should I track down the correct one?

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Yep, 3x3. Cut it and then filed it down to size. I'm going to go over the whole thing again tonight an make sure I don't have an air leak somewhere. It felt very strong with the 165 but that seems to big from everything I have read.

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Here is what I have settled on for anybody looking at this set up in the future. I'm still not very happy about the performance but this seems to be the best I'm going to get for now. I think I'm just expecting more that the bike is capable of.

JD kit-blue needle on 4th clip.

160 main

25 pilot

3x3 mod

0-3000 ft

cool temps

Full Yosh RS2

K&N filter

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