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Jeting help for a newbie.

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I have a 99 yz250 with an fmf fatty pipe and shorty silencer. Im running 93 with a 32:1 mix. I have been reading around alot about jetting, and am not sure if i really want to experiment with it yet. I was hoping there was someone on here running a setup similar to mine, that could tell me what they are running to steer me in the right direction. I greatly appreciate anyones help.

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unfortunately it'll be very rare that someone with an almost identical setup will be running at a similar altitude etc to you and ride their bike in a much similar way.

Just take the plunge mate and give it a go. There is great thread on jetting in the FAQ. I'm currently giving it a shot myself. I just wish there were more clear signs to tell if your bike is running lean or running rich based on either the 'seat of your pants' feel or the sound it makes. But I guess that comes with experience.

Note you can also buy JD jet kits for about $80 which a lot of people recommend to help with jetting.

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Fmf has a suggested jetting change pdf based off of stock on their website. So if you had stock jets to begin with, it will tell you what to change and where to set the needle. Its a lot of guess and check if youre new to it. The pros jet based on motor load, humidity, temp etc, so it can get as complicated as you want.

Just get a full can of premix, a few spark plugs, and an afternoon and youll get it

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Like the others mentioned, just find a good post on how-to jetting, read it 10 times, then print it and go to the bike to dial it in.

1. My personal best piece of advice is to make sure the bike is FULLY warmed up. If you can keep it running for 10-15min, go ahead and ride it around until it's as hot as as it's going to get before you start assessing the airscrew, pilot, etc.

2. Test you adjustments out by riding the bike... don't just twist the throttle on the stand until it sounds right. It needs to be under load for you to properly assess it.

3. For starters use this forum as you are now (welcome, btw) Go ride a little bit, notice what problem area(s) you are having, open up your carb and find out what size Pilot jet, Main jet, and what slot the clip on your needle is on, then make a post on here about it and we'll help you out.

4. First, first, first, make sure the floats in your carb are in spec and working properly. That is your first fuel-meter in your carb and if those are wrong you're just wasting time. You can be sloppy and just jet around improper float specs, but really you'll just be sabotaging your efforts, and the bike's performance.

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Thanks, I really appreciate the help. Im totally in the dark on this one lol. I'll continue trying to find some good articles on jetting.

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Search for "Spankey's Jetting guide", it's all over the web and it's my go-to for when I need a refresher.

Carbs are intimidating at first, but once you learn them out it's pretty easy. Don't get all caught up in temp, elevation, etc. just yet. Do one bit at a time.

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