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Questions About my 250EXC

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Well,

I took my carb apart piece by piece and clean it meticulously, then I checked and made sure all of my jets were the stock ones, and they were. Next I moved my clip on the needle to the middle position and turned the air screw to what the manual said. Then I drained the gas and put in fresh 93 octane with Dominator and mixed it 50:1.The only thing done to the bike is a FMF Gnarly pipe, yet the bike still has a lot of spooge and a little sputter at take off. Any ideas?

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The spark plug looks a little on the rich side but not too bad at all...I'm just not sure what to start with?

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if you "made sure the jets were the stock ones", you may not have the correct ones in. you need to find out what jets are needed for where you RIDE. elevation,temperature, and humidity all dictate exactly what jetting you need. "stock" doesnt really mean correct.

Joe

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Sounds a little like my '05 250EXC when I bought it, the previous owner was clueless about the bike other than replacing the gearbox oil after every ride. Anyway, start with running the fresh gas through and ride it up on the pipe (high rpms). I think my power valve had not been opened in over a year and it took a few hard passes with fresh gas to wake it up. Change the plug, for $6 make sure that you are starting with a good baseline - BR7EG / BR8EG race plugs are half the price of the shorty ktm plugs. This time of the year you should fatten(richen) the jetting to wake it up. Assuming that the air filter is clean and that the pipe is not dented up and the silencer is not packed with oil, richen the jetting a little at a time. I am now at full rich on the N3EH needle (bottom clip position) with a 162 main and a 40 pilot and I think it can take a little more fuel. 40* temps in very dense air (I am in New Jersey) means that it will need a fatter mix than most others. Start with the basics before replacing parts

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what year bike?

what temps are you riding?

what is the jetting?

main

piliot

needle, clip pos

AS setting

As Joe said, jetting is dependent on your location, climate and how you ride, and also which year bike you have.

How many hours on bike?

we need more info to get a full picture of what is going on.

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Elevation will effect it also. I am at 4000ft on my 02 250 EXC, and run this set up.

pilot 45

main 178

needle nuze clip in the 4th

Maybe this can get you closer if you are nearly at the same elevation.

Needle NUZE in the 4th

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Ok here my info on the bike...

Pilot Jet: 45

MainJet: 178

Needle: NOZG with the clip in middle groove

Air/Fuel Screw: 1.5 turns out

Hours: Unknown but I would say by kick starting it, its good

Reeds: Perfect Condidtion

Fuel: 50:1 Amsoil Dominator

Spark Plug: B7ES

Misc: Has hairline crack in Pipe, spits a bit of oil but runs like a striped @ss ape!

Riding Location: South Western Illinois/ South Eastern Missouri (St. Joe) don't know elevation, SORRY.

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unless you want to invest in more needles, you can work with what you have. some needles will just have a sputtery sections which are just inherent with them and aren't the best choice, but they work.

First, fix the cracked pipe. JB weld works well. A friend just fixed his son's 85 this way.

then, adjust the AS accordingly to help with the sputter, then you can adjust the clip pos, probably by raising the clip pos to #2. experiment, make one change at a time and take notes, narrowing in on the fix.

what year bike? 45 pilot seems big for a 250.

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The bike is a 2000.....will JB weld handle that kind of heat? Also, I have the air screw 1.5 turns out but it seems pretty responsive but I could always play with it a half turn each way. I am kind of wondering about the power of the bike to, the powervalve adjustment screw is turned almost all the way in, and clue where it should be?

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I have also just found out I ride at an elevation of 710-780 feet if that means anything to anyone. JD jet kits are looking pretty good right now but is it a waste to buy all of those jetsand needles?

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Do you have the manual? what is the stock jet sizes?

run the PV brass screw out to 1.5 turns from flush with case.

if you can't get it running clean with what you have, you can trust Mike when he says the JD kit works well.:thumbsup:

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I do have the manual and the stock jet sizes are 178 and 45. And you mean the screw right by the water pump cover needs to be turned 1.5 turns in from flush or 1.5 turns out from flush? Also, does this adjustment really make much of a difference?

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I do have the manual and the stock jet sizes are 178 and 45. And you mean the screw right by the water pump cover needs to be turned 1.5 turns in from flush or 1.5 turns out from flush? Also, does this adjustment really make much of a difference?

that is your fine tune PV adjustment. it controls when and how hard the PV opens, or hit occurs. the springs have more influence, but it does affect it. 1.5 turns IN from flush, or close to that, that feels right to you.

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Yea today I put on my CYCRA Hand guards and played with the preload adjuster, what a difference but I know its way too rich. I ran it down a back road and oil literally dribbled on my wheel. I just wish I knew how to fix it...I always heard that my model of bike was a power house but it feels like my 1993 CR250 that was a POS. Will a JD jet kit actually tell me what to do?

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Yea today I put on my CYCRA Hand guards and played with the preload adjuster, what a difference but I know its way too rich. I ran it down a back road and oil literally dribbled on my wheel. I just wish I knew how to fix it...I always heard that my model of bike was a power house but it feels like my 1993 CR250 that was a POS. Will a JD jet kit actually tell me what to do?

the JD kit has instructions and set up tips.

and yes, has your silencer been repacked?

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Yeah, I repacked it a little bit ago probably 2 months ago. I don't ride a ton, could it have already got soaked again? Also, I did a plug test today and it came out tan. It seems like if I run it hard it doesn't get all of the spooge, maybe I need a smaller pilot jet?

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Yeah, I repacked it a little bit ago probably 2 months ago. I don't ride a ton, could it have already got soaked again? Also, I did a plug test today and it came out tan. It seems like if I run it hard it doesn't get all of the spooge, maybe I need a smaller pilot jet?

no, your silencer should be fine unless it has really been spoogin'. It won't hurt to try a smaller pilot, but don't jet by the silencer. sounds like you are good on the main.

you can do a plug chop on the low end circuit as well. fresh plug and lug it around for a few minutes and shut it down.

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And if it comes out way too rich....smaller pilot jet or adjust the clip on the needle?

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