After adding an e-series slip on on my Raptor, it is running rich and the plug is completely black. So, I removed my front plastic and tank so I can get to the carbs...now what? Move the needles up a notch? and if so, how do I do it. remember, I'm a vergin.

 

Your sexual preferences have nothing to do with jetting your carb.LOL.

Okay now that we've got that all cleared up, go out an buy yourself a leaner jet, look at the number on the main jet (that gold hex like looking thing inside the carb) and go one size down.
For example if you had a 230 main and you wanted to go leaner you'd get a 220 or 210 main jet. Remember this the leaner the jet the smaller the number, the richer the jet the bigger the number.

Moving the needle valve to the middle position will help your mid range performance.

GOOD LUCK!!!

2000 SCRAMBLER 400 2X4

SCRAMDADDY400

 

Plug color is only a good indicator for full throttle mixture, you can get a black plug from idling, that really doesn't mean you are running rich on the top end. White Brothers have a good method to adjust carbs. If you have a idle mixture screw, you need to adjust that first, this will effect your idle mixture up to 1/8 throttle. You can usually turn it in until it runs rough, then turn it out until it runs rough, then screw it in somewhere half way between those two positions. Then move to your pilot jet, this is your 1/8 to 1/14 throttle adjustment. With a warm engine, ride it and go from 1/8 to 1.4, or idle to 1/4, does it hesitate, then it is lean, does it sputter, then it is rich, if it is crisp, then you are okay. Next is the needle, do the same thing, ride it, this time test up to 1/2 - 3/4 throttle, go from about 1/4 to 1/2 throttle and see what response you have going to 1/2 to 3/4 throttle. If it sputters you are rich and you need to lower your needle a notch, if it hesitates you need to raise it one. Now you can test your main jet, full throttle. You need a long strip to run at 3/4 to full throttle for about 30 seconds, after your run, pull the clutch and kill the engine. Remove your plugs and see if they are black, white or tan. Black, your main is too big, white too small, and tan you are okay.

Good luck, each time you make an adjustment you may need to adjust your idle mixture. Carbs are a lot of trial and error, and all motors are different, so there is no one change that will work for all the same bike.

 

Totally disregard what Scramdaddy said. In the first place your bike should not be running richer from a free flowing exhaust but leaner.And second, just because the plug is black does not mean you are rich, did you take a full throttle plug reading?If not the blackness on the plug may be a result of your quad idleing for a minute before you shut it off. Also, the Raptor jets come in half sizes, your stock jets are 140 for the left carb, 145 for the right.What else other than a black plug leads you to think that the bike is rich? You shouldnt have to mess with clip position just by installing a slip on system.

 

Usually the plug is a grayish tan color on the electrode, Black does mean it's running to rich.

It's probably near fouling, put in a new plug and try that.

2000 SCRAMBLER 400 2X4

SCRAMDADDY400

 

is your air filter clean??????????

 

BLACK DOES NOT MEAN IT IS RUNNING RICH! You can have a bike that is lean as hell and leave it to idle for a few minutes and the plug will be black even thought the bike is lean. That is why i suggested that he do a full throttle plug test. Im sure that you are used to your plugs being coated in nothing less than tar.But then again, thats a Polaris for you.
Blue leader, dont listen to this guy,I mean, would you trust the advice of a Polaris owner,or another Raptor owner.
Now watch Scramdaddy get all worked up over this and throw a fit.

 

Do what SauDvet says. He's right. One thing though Blueleader, when you lower he clip. you in hence raise the needle, The Raptor clip is in the number three position, ALWAYS count from the top down. Most people aren't leaning them out, which you are wanting to do, clip in number two position. Try SauDvet's suggestions first before messing w/ the needle.

 

Thanks everyone!! now all I need is the shop manual so I can see what is what and how to make all these adjustments. Should I buy the Yamaha manual or is there some kind of carb manual to buy. the Yamaha maunual is $50 or more. ouch!

 

Your damn right I'm going to throw a fit about this!!!

A black plug equals carbon deposits do to a rich fuel mixture, in lamens terms IT'S NOT NORMAL.

Here I'm tired of arguing go to this site http://www.fiatparts.com/colorplg.htm and read "carbon deposits", then try to tell me how normal that is.

I'm glad I own a polaris, that raptor sounds like junk if the plug is attracting carbon deposits like that, typical yamaha.

2000 SCRAMBLER 400 2X4

SCRAMDADDY400