Question on DRZ400

Fly'nBrian

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#1
I have a question on if this is OK. On my 01 DRZ kick, I removed the snorkle but have not re-jetted. After 180 miles of trails and serious riding I checked the plug. Just a golden brown looks good. But I have been told that with out re-jetting the bike would be lean.

Am I OK? Also with the themps nearing 80, will not the bike run richer? Or should I raise the needle.

This is my first 4-stroker so I am still a little lost on tuning.

I am going riding this week-end and don't want to fry the new bike.
Thanks in advance for any help.
 
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#2
Check thumpertalk.com . Also you failed to mention if you modified the tip. and yes I would say warmer temps and less dense air would make it richer technically. I put in a 165main and left the low at 45 and the mid at 65 but havent ran it yet with the snorkel out and the tip modified. I actually liked the quiet rascal and was somewhat pleased with the performance but want to get added grunt to carry my large frame up large hills.
 

Danman

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#3
I would say put in a fresh plug and take another reading. Did you change the plug after you pulled the snrokel? After the reading if everything looks good I would say that you are fine. Lean condition is realy hard on the pistion and can cause serious damage if left like that for a long time. I would check again an see what happens. The plug is cheap compared to what could happen if its lean.
 
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#4
No I have not done anything to the end cap, stock exhust. I think I will reinstall the snorkle for this week end just to be safe.

Fly'nBrian on the work puter
 
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#5
Brian, did you check the plug properly? If you let the bike idle for more than just a few seconds you will not get a true reading. Get into 3rd or 4th gear and ride it full open for about 20 seconds. At the SAME TIME chop the throtle, pull in the clutch, and hit the kill switch. Now stop the bike with the throtle still closed and the clutch pulled in. Now check the plug. If the insulator is white you are lean. If black you are rich. Tan is just about right. This will check the main jet. You do not have to change plugs every time you do this. It will change color as you ride it under different conditions. Do the same plug "chop"at half throtle to check the needle position. Then let the bike idle for about 3 minute and check the plug again. This will check the mixture setting. I've done this several times on my KLX300 and it works very well. I have had my main jet be bone white and after idling for 3 minutes had the plug turn pure black, then back to white again after a high speed run. Give it a try.:)
 
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#6
Brian,
Relax on the Snorkel thing. I think that the botttleneck in your system is the end cap and it will have the most impact on jetting until you modify it. So jetting is probably fine for now.
I bored out the tip and removed the snorkel. Main is at 165 now up from 145. and pilot is stock. I left the spark arrestor in to help control noise somewhat. I am pleased with the performance and have no reason to change pilot which was 45 not 42 which some people have. I think 2000 models had 42's and they also had a hickup. I can wack it open and it squats. It is midly louder with the tip holesawed out.

I did have some carb problems but they were all due to a vacuum line being off. It even smells rich at idle and stinks up the garage and when the wife comes out she yells about it. Then I start up the XR600 with the WB pipe and muffle her..

Now if snyone can tell me does turning in make the pilot circuit leaner? or is it backwards. From the posts I see, I would guess in=lean out=rich.
 

Shaw520

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#7
Someone correct me if Im wrong,...Rule of thumb;...If the screw is on the airbox side of the slide, it is an air adjuster,and will richen when turned in,...if the screw is on the engine side of the slide,.it is a fuel screw and will lean when turned in. Mostly I have seen air screws.