I have just pick up a 2010 ec250 which I am really looking forward to riding this year. I have read through the threads looking for tips and up grades. I would like to do the head and carb mods but I live in canada. Can somebody help a new gasgas rider out? New to gasgas but not riding I grew up racing moto and endro, most of the people I ride with still race, but I no longer have the time with a young family. I still like to ride hard and would really appreciate any tuning tips. Thanks
New to the gasgas world
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nambo-trev
New member
Congrats on the new bike bro, your going to love it. Were are you located in canada? I'm in Alberta I can give you my Jetting if your in this neck of the woods. What kind of set-up help are you looking for?
Jakobi
Super Moderator
Best advice I have is to ride the bike first and see what you think of its stock setup, and then address what you want to change. Is it new or second hand?
The engines are very tunable with many different needle tapers available to change the power delivery from smooth top to bottom, to more of a mx delivery.
Depending on the state of the engine you might want to pull it down and measure the squish, see where the piston sits in the barrel etc. Most like the top of the piston flush with the bottom of the exhaust port at BDC. This generally favours top end and over rev. From here you will want to measure the squish to see where you're at. You might get away with just machining some off the head, but more likley will be looking at doing that and then the bowl reshaped to correct compression. The stock squish bands seem ok but I think RB may make changes here. Any competent 2T tuner should be able to point you in the direction of someone who can mill the head down if you give them measurements.
I have found the carb doesn't need the mod, but will favour having the float height set correctly.
Thanks for the info I am just going by the things I have read on the net, forums and so on. I still have a month or so until the snow is gone, so I thought this would be a good time to set the bike up as best as possible before hand. My bike is use and will need some work (the price was to good to pass up) I have been riding for about 35 years mostly mx bikes but My last bike is a xc-w 300 But I really don't like the bike, transmission to wide and no over rev/ hit. I am going to check the squish band and see what the clearance is. I have done some work like this to my sons bike and my snowhawk. Jakobi thanks I will check the piston to ex port, I am looking for mx style power.
Jakobi
Super Moderator
No worries.. Here's some info GMP provided me regarding his set up
"Piston flush with lower exhaust port, works out to be a .5mm gasket in my bike. PV adjusted as described. Head modded for 1.2mm uniform squish, 195 PSI compression. USA pump premium gas. Vertex or S3 piston makes no difference, and I think they are the same anyway. From my experience, 250s are easier to jet than 300s, and are less sensitive to environmental changes. Remove the reed spacer if you have one. For 0 - 1500': 38mm AS1. #7 slide, 180 main, 45-48 pilot, JD Blue needle. if its less than 50 deg F I raise the pilot to a 48, thats it. 2K2 ignition w/12 oz weight, static timing advanced 1 deg. Bike RIPS, grunts, and idles! This is the bike that all others will be judged by, it runs that good."
I's also have to suggest the N3EW needle (stock YZ250). I'm yet to run one in a 250 but have been very happy with the N3xx needles in my 300. They give a somewhat mellow torquey bottom end and a really nice snap in the mid to top.
"Piston flush with lower exhaust port, works out to be a .5mm gasket in my bike. PV adjusted as described. Head modded for 1.2mm uniform squish, 195 PSI compression. USA pump premium gas. Vertex or S3 piston makes no difference, and I think they are the same anyway. From my experience, 250s are easier to jet than 300s, and are less sensitive to environmental changes. Remove the reed spacer if you have one. For 0 - 1500': 38mm AS1. #7 slide, 180 main, 45-48 pilot, JD Blue needle. if its less than 50 deg F I raise the pilot to a 48, thats it. 2K2 ignition w/12 oz weight, static timing advanced 1 deg. Bike RIPS, grunts, and idles! This is the bike that all others will be judged by, it runs that good."
I's also have to suggest the N3EW needle (stock YZ250). I'm yet to run one in a 250 but have been very happy with the N3xx needles in my 300. They give a somewhat mellow torquey bottom end and a really nice snap in the mid to top.
