GasGas ec250 2013 jetting?

[28gasser250]

Hi all,

Having a few issues with my 2013 ec250, can't get the tick over right & can't clear the top end when flat out (feels like it's holding back)

Running a 178 main & 38 pilot, have had the carb apart & all is clean.

Lots of oil out the back when running bottom end, doesn't matter how much I adjust the carb it always seems to change after it's been ridden or durning riding.

Any advise appreciated

[john r b]

Were are you located? Have you measured the squish?

[nickp]

Hi. Well where do I start (well this is what I have found I am no expert mind) if your tick over is uneven probably pilot jet too small, not revving out on top end main jet too rich. I like smooth, clean power. my set up is Suzuki needle NEDF (same diameter as original but different taper) 2nd clip, 45pj,172mj,as 2 turns out. Now this baby rocks clean, smooth, tractable, fast and ticks over like a swiss watch. 50/1 fuel ratio. I have tried lots of set ups this is the one I like best but as I said I am no jetting expert this bike is used in the uk.

[Jakobi]

First things first.

1) Determine the model of carb you have
2) Set the float heights for the particular model
3) Check current specs - including needle and clip pos.
4) Check back for more

The stock needle is crap. Thats being nice to it. The Suzuki and Yamaha/Ktm range of needles work much better and there is heaps of info on it. Don't forget this forum has people from all around the world on different fuels, different oils, different environments. You'll still need to determine what works best for you. The 2013 models with the Q stealth also run a bit different than the earlier ones (updated cylinder and silencer). As john said, if you haven't done the squish consider tightening it up. It'll simplify the whole process.

In Aus I'm running 40 N3CW#3 178, but only have 4 hours on my 2013R. Clean but torquey off the bottom. Felt a bit rich in the mid still, and while it revved out ok up top, I think I could likely drop the main a size. I'm doing the squish before I progress any further.

[28gasser250]

Ah now I've recently changed the head & put a more competitive compression insert will this affect it? I used an S3 cylinder with the red compression insert

[Jakobi]

What was your squish? Where was the piston in relation to the base of the exhaust port with the engine at bottom dead center? The specs I am using as above are the same as I use on my 2010 model with S3 cylinder and head using the black insert, however I had material machined out to reduce the compression ratio.