Jetting for 2000 250EC

[JCW]

I bought a nice used 2000 250MC, which has a 4 speed EC motor. It runs fine, and I have moved the needle clip up from the middle to the top clip since it ran a little rich. I checked the air screw today and it is 3 1/2 turns out. I backed it in to 2 turns and fouled a plug. I'm guessing my pilot jet is too big. Does anyone know the recommended jetting specs for this motor at 1000 ft with warmer southeastern weather?

Thanks,
John

 

[GMP]

John,

Do a search. There is much info here.

 

[JCW]

Thanks and I tried a search on "jetting" and on "250 jetting" and it did not filter correctly, as I got info on bikes for sale and everything else. No problem, I work it out myself. All I had done prior to today was move the needle clip up to the top position from the middle position and it was not bad at that point, although the plug was still dark brown (but dry).

This morning I took the carb out and it had a 38 pilot, 185main, and a N1EC needle. The 38 pilot sounded small enough (obviously not scientific) and since I did not have anything smaller I left it in. The 185 sounded pretty big based on other bikes, so I put in a 178 and put the needle clip back in the middle position. I'll play with it and get it dialed in.

Thanks

 

[JCW]

Since it was 78 and sunny, I couldn't resist taking the GG out to check out my work so far. I ended up back on the top clip with the 178 main (instead of the 185) and it runs much cleaner and sharper with no sign of being anywhere close to too lean. I may go down to a 175 or 172. It blubbered on the middle clip, but cleaned up nicely on the top clip. I think I'll also try a 35 or 36 pilot next week. Overall, this is a fun little bike and it feels 20 pounds lighter than my KTM250XCW. This jetting change also cut my fuel consumption in half!

 

[GMP]

Read this for some general good info.

http://www.gasgasrider.org/forum/showthread.php?t=1414&page=4

Your heading lean on the main to correct for a rich needle. Asssuming your float is set right and you have a #7 slide, you would be better with the N1EE or N1EF if you have them on hand. The LTR needle and other single tapers give excellent results. JD Blue works very well too.

 

[JCW]

Glenn,

Thanks very much for taking the time to get me this information. I did notice that the needle was very thin which generally means rich. All I have are a few KTM needles with totally different numbers. I will order the needles you mentioned. It looks like everyone was right around the 175-178 main where I am now, but they had 42-45 pilots which would be rich for me based on the way mine is running.

Right now it runs excellent with no hesitation or weak spot and it pulls hard and smooth to the top of the RPM range. My only issue is it's a little weak off idle compared to my KTMs, but I think that is due to the much higher 1st gear in the 4 speed tranny. It's only noticable when you come to a big hill at slow speed right out of a turn, etc.

Thanks again and it's been a real pleasure to join this forum. Any advice or information is greatly appreciated as I'm new to GasGas bikes. I'm really enjoying playing with it and I may try a new one as well as this one is working out. My fellow KTM riders all love it too.

John

 

[GMP]

If you buy needles, buy the single taper Keihin needles discussed and start there. They will provide a smoother power curve. The LTR kit is the easiest way to get near the bullseye. The JD Blue is excellent but $$. Once you get the needle leaned down you will find the pilot will need to be a little richer. All three of my GG 250s wound up a little different in prefered jetting, but the #7 slide was the best in getting the rest dialed.

All three of my 250s had very good off idle power, especially when running the FMF pipes. With the tighter 6-speed, I prefer the GG pipe for its smoother longer reving power. The MC 4-speed however, with taller first, may be a good app for an FMF Gnarly. The MCs came stock with a Messico that is a lot like the GG pipe.

One of my buddys (Bucksnbikes) still rides my old '00 XC, and it still works well.

If you like the '00 MC you should try an '07 EC.

 

[JCW]

Thanks again and I'm considering an 07 250EC or maybe a 300. I rode a friend's 300EC a few years ago (an 03 I think) and it was excellent.

My 250MC bike has an FMF Gnarly on it now. I'm going to try a few of the needles and also see if I can find a 12 tooth front sprocket (currently 13-51) and that should drop first down nicely and put some torque down low. Since our trails are pretty tight and technical I should still have enough top end for the small # of 4th gear sections we have. I can also quickly swap back to the 13 if needed. Regardless, it's not my main bike anyway so it's not as critical. It has given me something to play with that I enjoy riding as well and it's been fun. Everybody needs a fun project bike.

Thanks again,
John