I have a 2006 Gasgas EC 300 and currently 38mm carb. My jetting is 40 pilot, DDK needle 2nd from top, and 180 main. 180 is a little lean for the 35 degrees it was today, but I'm thinking it will be about right when it warms up a bit. It runs very nice bottom to top, however I wonder if a 36mm carb will give me a little more punch down low. I had 150 psi compression cold (seems low to me, but read here it is normal for Gasgas), and currently a fatty pipe, but want to go to a gnarly pipe. I like to ride lower in the RPM's, and while it's currently smooth and linear through the power, I could stand to loose some top end in favor of low rpm grunt. I guess my questions are #1, will the 36mm body produce a noticeable improvement in low rpm's, #2 will I need a new carb boot/reeds to fit the new carb? Also, if there are any running a 36mm carb on an older 300, what do you have for jets and needle?
36mm carb swap
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I doubt it's worth the effort to make the change. While the 36 in theory might be better at partial throttle, I don't think you could really tell the difference. Just jet it as clean as possible and spend the money on fuel or riding gear. If the money is burnng a hole in your pocket maybe a Lectron or Smart Carb is worth trying.
dANbOT
New member
While it wasn't a 300, I found good results switching to a 36 on my CR250. Gained a little throttle response below 1/2 throttle, and the big difference was how low in rpm I could lug the engine down.
If I remember correctly, I had to go 1 step leaner on the pilot, and half clip leaner on the needle. ( to compensate for the increased signal)
To answer your other question, the Keihin 38mm and 36mm carbs use the same body and would not require a different reed boot.
If I remember correctly, I had to go 1 step leaner on the pilot, and half clip leaner on the needle. ( to compensate for the increased signal)
To answer your other question, the Keihin 38mm and 36mm carbs use the same body and would not require a different reed boot.
What head mod? Shaved to increase compression? I'd rather use a thin base gasket and increase compression with the side benefit of lower exhaust ports.
(F5)
Gold Level Site Supporter
From the home page you can find your way but here's the link if I get it right.
http://www.rb-designs.com/rb_designs_llc_005.htm
Do check the homepage of this site if you haven't there's lots of good stuff not on the forum. Link bottom of the page right hand side.
Here's my own thread if you want to DIY but ignore that last few pages where I got into an unrelated spin. Actually I just reread it and it isn't a bad bit of writing if I say so, well compared to my usual drivel.
http://www.gasgasrider.org/forum/showthread.php?t=16560&highlight=head
http://www.rb-designs.com/rb_designs_llc_005.htm
Do check the homepage of this site if you haven't there's lots of good stuff not on the forum. Link bottom of the page right hand side.
Here's my own thread if you want to DIY but ignore that last few pages where I got into an unrelated spin. Actually I just reread it and it isn't a bad bit of writing if I say so, well compared to my usual drivel.
http://www.gasgasrider.org/forum/showthread.php?t=16560&highlight=head
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Flashlight
New member
I think I would try a few other things first before spending the coin on a 36mm. I have a 2006 EC as well. I?ve owned it for 2 years now. It had a DDK in it when I bought it. I was really disappointed in the low end at first. My KDX 220 had way more low end. The first thing I did was set the powervalve spring tension. The powervalve was not closing at small throttle openings. (see the sticky at the top of the 2 stroke engine section ). That was a major improvement. I then went to the Yamaha/KTM N3EG needle with a 42 pilot and a 178 main. After that I sent the head to RB designs which smoothed out the power and definitely improved the mileage. Those three things changed into another bike, I mean like almost too much bottom end. Really nice for big log hopping and steep hills that have no run up.
The DDK seems to be a lean to rich profile. I had better luck with a 42 pilot 2nd clip and 175/172 main. I didn?t spend a lot of time (3 or 4 rides) with the DDK but if anything it felt like it could stand a 45 for a pilot. You are running that Fatty in cooler weather so you may need that 180. I run the stock pipe.
I have a 36mm on hand, so no money lost. I have been finding that DDK is not a good needle for this either. Pilot and main seem fine. I run at 1 1/2 turn out air screw, and a plug chop shows the main to be ok. Still, the DDK on third clip position runs very rich, yet on the 2nd its not perfect either. Its borderline lean from 1/2 throttle to main jet, yet rich at about 1/4 throttle. I am thinking a NEDW is the best for me, but many recommend the N3EG as well.
I'm not disappointed in the raw power of my bike, I'm simply looking to make it smoother and stronger at the extreme low rpms, say 600-1200 rpm. Its a smooth and linear curve from bottom to top, but the top end HP will scare you. From idle up it seems ok. I just have no use to wring my bike out to 8000 rpm the way I ride. Its fun in the yard, but it would get out of hand in the rough stuff. Its possible my fatty pipe isn't doing me any favors.
I'm not disappointed in the raw power of my bike, I'm simply looking to make it smoother and stronger at the extreme low rpms, say 600-1200 rpm. Its a smooth and linear curve from bottom to top, but the top end HP will scare you. From idle up it seems ok. I just have no use to wring my bike out to 8000 rpm the way I ride. Its fun in the yard, but it would get out of hand in the rough stuff. Its possible my fatty pipe isn't doing me any favors.
motopsycho87
New member
If you want more low down hit at the cost of top end, fit the ec125 or Suzuki rm125 cdi, but be warned, it's fierce, in the wet slippery conditions today I could barely grip at all. Also, use high octane fuel to resist pre-ignition.
motopsycho87
New member
Also as far as I'm aware the AS1 and AS2 crossover, keoon doesn't state any differing dimensions
It's not necessarily to increase compression, it is the "squish" that is important. As I understand it, this is just the rim that sits within the cylinder walls and how close it is to the top of the piston - it essentially forces the air/fuel into the the domed combustion area. The dome shape within the head would have to be shaved to keep the compression ratio the same or at safe levels depending on how much material is taken off the head.
So, in theory, the bigger your squish measurement is, you're bound to have an incomplete burn meaning poor economy and lacking power. This mod increases bottom end!
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The AS1 carb is 15mm(front to back) longer, at 91mm in length than the AS2 carb, which is 75mm in length.
