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My jetting experiment from last night

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Took a look last night at what my new '04 "S was set at. Drilled out the fuel screw plug & removed the bowl. also I removed the top of carb containing the slide & needle.

Main jet: 142.5 left it alone I have a 140 & a 145 on hand but it is fine the way it is.

Pilot jet: 22.5 left it alone for now.

needle: took the small shim that was on top added it to the bottom to raise the needle a little.

Fuel screw was at 3 1/4 out stock bumped it out to a 3 1/2.

Cranked it up & it sure runs smoother off idle & now when you whack open the throttle in 1st or 2nd gear it comes up & does not bog. I have done jet kits in the past with mixed results so I thought I would tinker with the carb to begin with before sinking $60 bucks on a might or might not work setup. I am not looking to create a fire breather just a clean reliable carbed engine. I am at 300 ft. sea level but do venture to 3~4k feet up in N. Ga. Bike ran okay up there completely stock with a little bog when coming off turns with the revs down low. It has always cranked well cold. I might bump the pilot up to a 25 & back in the fuel screw a turn in the future but for right now I am happy with it the way it is. The snorkle is still in do you think it will screw up if I remvove the snorkle? I am not going to cut the airbox for the 3x3 mod, just not doing it.

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Have you drilled out the end of your exhaust with an 1 1/4 or 1 3/8 bi metal hole saw yet? All this does is get rid of the "restrictor" tip, and makes it flow a little better I'd imagine. The spark arrestor isn't affected and it looks stock if you can cut a clean hole and/or clean it up after. I'm not too sure about the snorkel removal :awww: I'm wanting to remove mine as well but I'm very unsure as to whether I want to do the 3x3 mod. I do think removing the snorkel will change the amount of air the engines getting....how much I don't know. You said your fuel screw was set at 3.25 turns out from the factory...wow :lol: I've ordered the extended fuel screw for my bike, my friend has the same bike (03 KLX400SR) and his fuel screw from the factory was almost all the way in :thumbsup:....like only .25 of a turn out :devil: It made a HUGE differnce when he adjusted it to 3 turns out. Do you think switching positions of that washer helped out, did it raise the needle much :D

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Yes adding the washer to the underside of needle did help. It would stall before doing this right off idle. I am planning on adding a #25 pilot jet this weekend so I will be backing the fuel screw in about a turn to begin with & go from there. Yep it was 3 1/4 turns out from the factory. A good friend who bought his '05 3 days before I bought my leftover '04 had his screw at 2 3/4 out stock, closer to 3 turns out actually. He has not done the washer thing yet. The thin washer is maybe .5mm thick at best. I replaced the removed top washer with another one on top so the small top spring would still have a smooth contact surface. I have a 1mm washer I might try just out of boredom to raise the needle a little higher. Everything is fairly easy to do with the carb on the bike, just loosen the clamps, remove the throttle cables & spin it towards you. I am pretty pleased with it now but it may be to rich in the higher elevations that I ride in 3~4 times a year. I might remove the snorkle this evening & take a ride at the current settings before messing with the #25 pilot jet tomorrow.

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I have not drilled out the end piece on the exhaust & I don't plan to. I did that to my '01 "E" & it just made it louder. I could not detect any more power from doing this. I like the quite pipe on the bike as is. Noisy pipes will get you into deep trouble if your somewhere your not suppose to be at. :thumbsup:

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RoyH, I am just curious why you aren't interested in the 3x3 mod. I just did it this weekend with the burneds suggested settings and it is amazing the difference. From start to finish it took about two hours and it is the first time I ever looked inside a carb. Hardest part is getting the float bowl screws off.

I am much higher elevation then you though and I was getting a very nasty bog with stock jetting. I figure if I am going to rejet for altitude why not do the 3x3 mod. Good luck :thumbsup:

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I don't have a issue with the 3x3 mod I simply think it is not for me at this time, that's all.

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3x3 mod is that good huh? I just ordered my DJ kit from TT the other day. Am I really gunna feel that much of a difference?

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Yes. The 3x3 is definately a good mod. :thumbsup: The E/K models come stock with a 3x3 hole, they didn't do it for nothin'.

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Even if you don't buy the DJ kit I highly recommend the 3X3. I did the 3X3 before I bought the DJ kit :devil:. You will still have to rejet even if you don't buy the DJ. That 3X3 hole makes a noticeable difference. :thumbsup:

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roy, i played with the carb on my 02s a bit just as you. I pulled the snorkel and began to move things around. I shimmed the needle up using shims from another carb. had the fuel screw from 2 3/4 out to 3.5 then back to 3 and little adjustments in between. I could never get happy with it when the snorkel was out with the stock jets. It seemed too rich which is weird but it would bog down low and i still had the surging at cruising. I was able to get it much better dialed in leaving the snorkel in.

good luck with it.

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you can shim the needle till your blue in the face and it will never do any thing about the lean straight diameter of the needle.

the main jet also rich with the stock hole,but if you lean the main it wont cover up the stock lean needle and it wont run well.

it will have good peak power but will be weak in the midrange. :thumbsup:

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