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Thinking (too much?) about jetting

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I've read a lot of threads about this but still haven't found exactly what I'm looking for.  I'm pulling my 2004 DRZ400S out of storage sometime this week and getting it ready for the season.  I live at 9,000 ft, but my first ride of the year is probably going to be at around 5,000 ft.  I was going to pull the 145 main jet I'm running and put in the 150 adjusting the needle from the 2 clip to the 3rd, then re-jet once I got home.  I already have the extended fuel mixture screw in place so I started thinking that I should just run the 150 jet set up and adjust the fuel screw to compensate for the higher elevation where I'll be doing most of my riding.  I will be going down in elevation for rides until late May or June depending on snowfall, but riding on the street when I'm able.  Are there any disadvantages with this?

I'm new to posting on this forum, so please forgive me if I didn't get the right search words in and there is already a post about this.

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Bgringo, 2 pieces of advice:

The first is this link to a Google Sheet with all kinds of jetting scenarios:

https://docs.google.com/spreadsheets/d/1HNSB3DrqJqHTInjVDKKS4HNSHZPbdK0ElbfNI5HxuZg/edit?hl=en#gid=1172546203

The second is just my experience with a JD Jet kit living in Boulder (5,500ft and typically riding up in the mountains around 9k).  I tried jetting for high altitude with a 145 main jet and red needle on second position from the top.  Riding at 5,500 I felt like the bike was running rather lean.  I adjusted to a 150 main and red needle on third position and now it runs great, at least at 5,500ft.  I did also install an MRD Z-Pro exhaust at the same time as my re-jet, so it's somewhat difficult to compare the two jetting postions.

Perhaps the only good thing about the Mikuni carburetor on our bikes is that it supposedly adjusts itself for altitude changes better than the FCR...

My previous thread on this topic is here:

Good luck.

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I am running a 155 main,blue needle clip 3 and 25 pilot at 1753m above sea level with the JD kit,powerbomb header and fmf pipe with a foam filter-runs like a bat out of hell.These settings were according to James Dean by the way.

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Thanks RockyMntnMike,

I did read your post about elevation jetting and the spreadsheet of data.  I'm reverse of most of the posts I read about it.  I'm already up high and am looking for the lazy way to change to a lower and then back to higher without having to swap the jets every other ride.  I'm just trying to find out if I go with a richer jetting and then dial off the fuel using the fuel screw will it work?  I haven't seen anything out there mentioning it, so I'm just going to do it and see what happens.

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5 hours ago, Bgringo said:

Thanks RockyMntnMike,

I did read your post about elevation jetting and the spreadsheet of data.  I'm reverse of most of the posts I read about it.  I'm already up high and am looking for the lazy way to change to a lower and then back to higher without having to swap the jets every other ride.  I'm just trying to find out if I go with a richer jetting and then dial off the fuel using the fuel screw will it work?  I haven't seen anything out there mentioning it, so I'm just going to do it and see what happens.

Won't have much effect except idle and a bit more.  I'd jet just a bit rich on the mj at 9k and move the clip around until I found an acceptable compromise for the elevation changes, if there is one.

Edited by npm

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