2002 Gas Gas EC300 Jetting Issues

[Vergey]

I am looking for a little advice oh wise Gas Gas forum members. I have been lurking on the forum for quite a period of time and trying to piece together information to fix the long list of issues with my EC300.

So a little background, bought the EC a little over a year ago, decided I fancied my first 2-stroke enduro bike. Rode a friends and fell in love with the GG, so got my own. Unfortunately for me the previous owner of my bike did not seem to have had the enthusiasm that I have for the bike. On my first proper ride the bike went pop- cracked block caused it to spew out all its water and melt the block the piston- you name it, it was buggered.

So I have thrown a hell of a load of money at it fixing that- renewed every bearing, crank, piston, new barrel, new head, basically everything new except the actual gears. At a cost of nearly ?2000- I figured it would be worth it because I would essentially have a zero hour bike, all be it with knackered body panels. (At least that way I feel less bad when I clip trees.)

Anyway I have then spent the last 9 months chasing issues around the bike, including the jetting- to start with it was ok- not great but rideable. Plug chop suggested it was a little on the rich side. But I figured that it probably wasnt a true reflection of the jetting as the exhaust was looking seriously tired, and I was getting a lot of exhaust leaking through the PV breathers. This situation just got worse as time went on, with the bike getting to a point where it wouldn't rev out and was slow as all hell.

So I purchased a DEP silencer, and replaced all the PV bearings- silencer looks fantastic and sounds fantastic. (The front pipe is the standard GG stainless item- nearly new so didn't replace). The only issue I have now is that the bike it running on the lean side- plug chop shows no colour on the centre electrode insulation- with the ground electrode looking slightly on the white side

So I dropped the needle clip one down, back to the centre of the needle (N1ec), which merely made the bottom end run badly. It now really stutters at low throttle, particularly pulling away, but as it revs out it clears up and takes off, it really revs out, but it what I would describe as slightly zingy. Pulled the plug, still white with no real change in appearance

I will also add that the bike has very low hours approx 40, and before doing this jetting work I have inspected the entire engine, the compression is good, the air filter was brand new, reeds look as new (again only 40 hours).

So oh wise ones, please help- what do I need to change to get the bike back to a ridable state, where I don't need to worry about it going bang again- I cant afford to fully rebuild her twice in two years.


Summary:
2002 Gas Gas EC300
Boyesen Carbon Reeds
DEP silencer
Standard GG stainless front pipe
35 pilot
178 main
N7 slide
N1ec needle
BR8eg plug

I hope this is enough info (sorry if it is a little too much of a life story but every little helps). All suggestions and help will be greatly appreciated

[oldnslow]

Hi, I am in UK too, best settings for my bike were as follows
38 pilot
175 main
NEDW centre clip
A/S 1.5 turns out

Bike ran strong right through range with smooth transfer onto pipe
Hope this helps its gotta be worth a try

[Harry]

02 EC300

pilot: 38-40
needle: N3eg ( yz250 )
main: 178
slide: no.7

= happy days

[gassergrant]

Originally Posted by Vergey

I am looking for a little advice oh wise Gas Gas forum members. I have been lurking on the forum for quite a period of time and trying to piece together information to fix the long list of issues with my EC300.

So a little background, bought the EC a little over a year ago, decided I fancied my first 2-stroke enduro bike. Rode a friends and fell in love with the GG, so got my own. Unfortunately for me the previous owner of my bike did not seem to have had the enthusiasm that I have for the bike. On my first proper ride the bike went pop- cracked block caused it to spew out all its water and melt the block the piston- you name it, it was buggered.

So I have thrown a hell of a load of money at it fixing that- renewed every bearing, crank, piston, new barrel, new head, basically everything new except the actual gears. At a cost of nearly ?2000- I figured it would be worth it because I would essentially have a zero hour bike, all be it with knackered body panels. (At least that way I feel less bad when I clip trees.)

Anyway I have then spent the last 9 months chasing issues around the bike, including the jetting- to start with it was ok- not great but rideable. Plug chop suggested it was a little on the rich side. But I figured that it probably wasnt a true reflection of the jetting as the exhaust was looking seriously tired, and I was getting a lot of exhaust leaking through the PV breathers. This situation just got worse as time went on, with the bike getting to a point where it wouldn't rev out and was slow as all hell.

So I purchased a DEP silencer, and replaced all the PV bearings- silencer looks fantastic and sounds fantastic. (The front pipe is the standard GG stainless item- nearly new so didn't replace). The only issue I have now is that the bike it running on the lean side- plug chop shows no colour on the centre electrode insulation- with the ground electrode looking slightly on the white side

So I dropped the needle clip one down, back to the centre of the needle (N1ec), which merely made the bottom end run badly. It now really stutters at low throttle, particularly pulling away, but as it revs out it clears up and takes off, it really revs out, but it what I would describe as slightly zingy. Pulled the plug, still white with no real change in appearance

I will also add that the bike has very low hours approx 40, and before doing this jetting work I have inspected the entire engine, the compression is good, the air filter was brand new, reeds look as new (again only 40 hours).

So oh wise ones, please help- what do I need to change to get the bike back to a ridable state, where I don't need to worry about it going bang again- I cant afford to fully rebuild her twice in two years.


Summary:
2002 Gas Gas EC300
Boyesen Carbon Reeds
DEP silencer
Standard GG stainless front pipe
35 pilot
178 main
N7 slide
N1ec needle
BR8eg plug

I hope this is enough info (sorry if it is a little too much of a life story but every little helps). All suggestions and help will be greatly appreciated

hi mate welcome,im from herts to lol (potters bar)

ive been having trouble to ive changed my needle just lately

slide 6
178 main
38 pilot
N3EG clip pos3

had a bad burble at low to mid and this needle cleaned it up, if you need a hand with anything give me a shout

[motopsycho87]

My jetting is in my sig, N3EG was the best thing I ever did!

[Vergey]

Thank you everyone for all their suggestions, certainly looks like the N3eg needle is the place to start. I will let everyone know how I get on, thanks once again.

[Vergey]

I have one question- gasser grant you are using slide no6 where as Harry has very similar set up bar using the standard no7 slide. How much of a difference does the slide make, and if the answer is lots what led you to change the slide.

[gassergrant]

Originally Posted by Vergey

I have one question- gasser grant you are using slide no6 where as Harry has very similar set up bar using the standard no7 slide. How much of a difference does the slide make, and if the answer is lots what led you to change the slide.

The slide is standard as far as im aware, I have not changed it.
im not sure if its leaner or richer hopefully someone can explain.
yo might want to up the pilot jet to a 38, I was going to down size to a 35 but I got rid of the n1ef needle

[Vergey]

I have ordered the needle and a 38 and 40 pilot to see which is better, as I said I kind of want to be on the safe side, cannot afford another melted piston and block

[gassergrant]

don't blame you mate sounds like you have spent a lot of money on your bike.

I think your old needle is leaner ? and a 7 slide is leaner and lean is bad