Power Issues 2010 250EC

A

andrewjtheis

New member
So I have combed the threads, and I found a few similar, but wanted to post my own with my own issue. here are the details:
2010 250 EC
185 PSI Compression
Brand new Pack on FMF Turbine Core
Fresh clean air filter
Kehein Carb
Fuel: 50:1 Motul 800 oil
Decent size dent in pipe (i think this has NOTHING to do with this)
Jetting:I can't remember the jet #'s but all of them are leaner than stock.
Spark Plug; NGK BR8EG, color looks slightly wet, but not horrible.
My problem is: i have absolutely ZERO mid range power. after 1/4 throttle its bogging VERY heavily til i get up into 3/4-full throttle, I moved the needle down one notch (it was all the way up) and even then its weak at best. I am also getting a TON of spooge (black) out the tail pipe already with the silencer freshly re packed. COnventional wisdom says its rich, but the plug tells differently and the bike is already jetted lean. I have heard crank seal, but i have no experience with this. any help is greatly appreciated. thanks guys!
 
Pull the pipe and make sure the power valve arm is correctly attached, these break on the early models. Then put just the pipe back on and run it to see if the power valve is moving under engine rpm.
 
Pull the pipe and make sure the power valve arm is correctly attached, these break on the early models. Then put just the pipe back on and run it to see if the power valve is moving under engine rpm.
Other than that do a leak down test on the motor, it will tell you if you are leaking oil in to engine via the transmission.
 
You can't tell squat looking at the plug. It's a roadrace thing for full open (mainjet) and only counts for a set test procedure.

Above good suggestions.

Then pull carb. Clean and blow through every hole and check hoses. Then with good light and a magnifier of some sort check you needle jet hole. The orifice should be round, not even slightly oval.

Then read what needle you have . If it's a N1FE or whatever std is that will be a large part of the problem. Moving it on the clip won't help it being too skinny to start with. Cut it in 1/2 so you're not tempted into using it again. Really.

Read the jetting threads here.
 
As F5 has already mentioned, it sounds like you need a different needle in your carb. Identify what needle you have and read through some of the jetting threads.

I've tried a few different needles but I've settled on a Suzuki NECW needle, it's running great, but mines an old 2004 EC300 with an AS1 PWK38 carb.

If you're in the UK or Europe and need any Keihin jets or carb parts I can recommend this guy based in Holland...

https://www.frankmxparts.com/

He also has a shop on eBay...

https://www.ebay.co.uk/str/frankmxparts

I've used him quite a lot, very helpful and great service. :)

All the best, Dave.
 
Okay thanks guys. Just an update:
Idle jet is a 40
Needle is an N1EG
Main is a 170

Haven?t Checked the power valve. Pretty new to 2T all together so I?m not sure how to check the ?arm? I guess seeing if the power valve moves freely? Sorry, and thanks!
 
So a JD needle would work better? I bought a kit for my KTM 200 and it did absolutely nothing, felt like i wasted my $$, but with all the comments here it seems my needle might be my problem.

on another note, the guy i got it from said it needed to be HOT to run right. I have not been able to run it for more than 10 minutes at a time, is this common with the bikes? Thanks again so much guys.
 
For sure, please try a different needle.

I've heard good and bad reports about the JD jetting kit, my own personal opinion is you'd be better buying a selection of 2 or 3 Suzuki needles, think this would work out better value.

Try the NECH and NECW and NECJ.

No, your bike doesn't need to be run HOT. Just get it warmed up gently before you give it any hard acceleration or high RPM but once it's up to normal running temperature it will perform fine...as long as it's jetted nicely. :)

All the best, Dave.
 
These tables will help you with the Suzuki needles...

Be aware, the only difference between the NEC* and NED* needles is that the NEC* needle is half a clip position leaner than the NED*, or vice versa.

NE (1).JPG

NE (2).JPG

NE (3).JPG
 
First time through the gears 2 strokes often run a little soggy. This can be traced down to fuel not atomising as well some people figure, but I think it is more to do with the old floatbowl full of gas in a small vented area loses its light end gasses quickly.

I try to run out the fuel by turning the tap off on the way back to the carpark at the end of the day, and mixing in some new gas the morning of the next ride before opening the tap.

None of this is much issue if you ride every week.
 
andrewjtheis said:
Thanks Dave! Now where can I find these bad boys? Did a quick search through my normal channels.
Click to expand...

Where in the world are you?

I would try a Keihin dealer or Suzuki spares dealer. You can also try eBay but keep an eye out for cheap/fake parts from China, although normally these seem to be pilot jets and main jets, not needles.

If you're in the UK or Europe and need any Keihin jets or carb parts I can recommend this guy based in Holland...I'm pretty sure he ships worldwide too.

https://www.frankmxparts.com/

He also has a shop on eBay...

https://www.ebay.co.uk/str/frankmxparts

I've used him quite a lot, very helpful and great service.
 
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