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DRZ400S jetting advice please

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I wish I could give more accurate numbers on the altitude but here in Colorado it's just a crap shoot up in the mountains. Concerning the bike itself, I bought it as a frame, engine, carb, and radiator and put the rest of the bike together from spare parts. I have a complete JD Jetting kit that came with:

Main jet 145

Main jet 150

Main jet 155

Main jet 160

Pilot jet 25

Needle clip

Float bowl cap screws

Blue needle - low alt./cool temps

Red needle - high alt./high temps


2002 Suzuki DRZ400S

2)conditions (elevation,temp,humidity if extreme,type of riding)

6,800 - 9,000 above sea level, 50-80 degrees F, 50% humidity Slow trail riding

3)modifications (pipe,air box,motor)

3x3 airbox mod, baffle removed from exhaust, everything else is unmodified

4)current jetting.the answer to this question is not "stock".i tune hundreds of different motorcycles.as much info as i do remember it is not physically possible to remember the stock jetting for everything.i need to know the complete stock jetting including needle code.

142.5 main jet, 22.5 pilot fuel jet

5)running issue that is trying to be cured.

None. Yet.

6)does the running issue change?affected by motor temp?better or worse when hot?better or worse when cold?


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Been running into some problems since the rejet. Only happens at normal operating temperature. I'm here in Colorado Springs.

Also, I never got around to removing the baffle. Will this affect things?

-Will die at idle. Once it gets hot it will run for 3-4 minutes then shut off. It fires right back up though. It will stay running just fine with the choke on.

-There is a slight slight skip at idle. It doesn't purr but it doesn't sound that bad either. I've never had my hands on a good one so I don't know if that's normal. I'm a mechanic and I feel it's something I could pick up but not a lot of others.

-At idle, I have to ease into the throttle to rev it. Giving it a good blip or yank will bog it out.

-As soon as I put it in gear and let the clutch out it bogs out. I can ease the clutch out very slowly and it will go on it's own accord.

-I have to ease it into the RPMs. As soon as I try to give it a good blip it bogs.

-Once it gets going, it will stumble at lower rpms and then pull hard at higher rpms.

-I came across some ice on the road and pulled the clutch in and it died as I started to slow down.

-Shifting into a higher gear, it will continue to be a dog until higher rpms

I shut the fuel off and brought it home, figuring this was above my head.

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Before I started typing this message I went and double checked so as to not feel like an idiot if I was wrong.

There is no provision for a vac line on the petcock.

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I'd also like to clarify that I have an E model. It was in pieces when I got it and from what I had I gathered it was an S model. I now know better. In another thread initially looking for jetting advice I referred to it as an S.

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