engine will not rev after being driven on low revs

[Nick1000]

Hi

I purchased a gasgas ec300 2013 some months back. When i have been riding on low revs for some time on singletrack and trials ridning it is struggeling to rev out fully when i come out into the open. it revs but is revs unclean and does not reach maximum revs. after 3-4 runs of ful rev straights it comes back to life. have you got any tips on why this happens? i also have black oil coming out of the back of the silencer. am i running it with to much oil or do i need to set up the carbertor differntly? i am greatful for any help i can get.

 

[n_green]

You are way too rich off the bottom. I'd guess you are running standard jetting. The bike will load up with fuel off idle and then be that rich it can't rev out properly. Have a look at the jetting thread and see what others with your bike are running. Spooge has nothing to do with oil ratio so don't worry about that.

 

[Nick1000]

You are way too rich off the bottom. I'd guess you are running standard jetting. The bike will load up with fuel off idle and then be that rich it can't rev out properly. Have a look at the jetting thread and see what others with your bike are running. Spooge has nothing to do with oil ratio so don't worry about that.

Thanks alot for this information, i will take a look at the jetting thread!

 

[Niall-griffiths]

I have the exact same problem with my bike unless i keep it on the pipe it does this ! and wont clear until i run it hard for a while i have little time to look at it tho but was told it sounded like rich jetting let me know how u get on !

 

[Nick1000]

i checked the manual and as i am running in sweden where we have 5-8 degrees celcius right now the recomendation is to tighten the mixture screw. This however enrichens the mixture wich seems to be in the wrong direction. I will however try this at the weekend and will get back with info how it works out.

 

[Jakobi]

The stock needle is too rich for the new engines and AS2 carbs. Gas Gas has changed a lot of the bike over the last 10 years but somehow still thinks the same jetting is good enough.

In saying that, even with what I would typically run on my 2010 model, I am finding doesn't quite work on the 2013 even though the engines are setup very similarly. Even running at what I would consider to be quite lean on the needle position I'm getting a bit of spooge although it could just be burning off excess as the last ride where I chugged around a lot I had it dripping from the silencer/pipe join down onto the swingarm. I'ma blame that 4 stroke can! Q stealth spooge trap.

 

[Simmo737]

Grand jetting master, you need to cut some plugs up and report back, I reckon the new barrel likes it lean. Expectantly waiting.....

 

[Jakobi]

Grand jetting master, you need to cut some plugs up and report back, I reckon the new barrel likes it lean. Expectantly waiting.....

I think it likes it more like a ktm. Leaner pilot, leaner diameter, richer on the clip pos, and then leaner main. Thats my thoughts. Been hard to test too though as its been sloppy so lots of sustained low rpm chasing traction. I have noticed it splutters up in the rpm quite a bit in the lower gears with even the 175 main, but it could be water being pulled through the filter as well. Hard to test.. but definite spooge city even with 40 N3CW#3 175.. Going half a clip leaner really shows a lack in low end grunt, while closing the airscrew brings bck some of the grunt around 1/8th-1/4 throttle it blubbers down low and won't idle as well an is not as crisp as I like. I'm thinking of moving to a leaner diameter needle in the same position, same pilot and dropping the main one more.

 

[gasser]

Cold weather and a motor that doesn't run at regular operating temp because you are lugging it a lot. Before you change your jetting drastically change your premix oil if you are using one with a high flashpoint (above 100C or 212F). I don't know about oils available in your country but here are some in the USA.
Amsoil Intercepter, Amsoil Dominator - both good
Amsoil Saber - bad
Motul 710 - good , Motul 800 - bad
Champion WP2 - good

 

[Jakobi]

Gasser, I'm using Amsoil Dominator at 50:1. Other bike runs clean on the same fuels and oils.

 

[cbutler]

Cold weather and a motor that doesn't run at regular operating temp because you are lugging it a lot. Before you change your jetting drastically change your premix oil if you are using one with a high flashpoint (above 100C or 212F). I don't know about oils available in your country but here are some in the USA.
Amsoil Intercepter, Amsoil Dominator - both good
Amsoil Saber - bad
Motul 710 - good , Motul 800 - bad
Champion WP2 - good

Why is Saber bad my bike runs killer on it better than dominator???????

 

[Simmo737]

I think it likes it more like a ktm. Leaner pilot, leaner diameter, richer on the clip pos, and then leaner main. Thats my thoughts. Been hard to test too though as its been sloppy so lots of sustained low rpm chasing traction. I have noticed it splutters up in the rpm quite a bit in the lower gears with even the 175 main, but it could be water being pulled through the filter as well. Hard to test.. but definite spooge city even with 40 N3CW#3 175.. Going half a clip leaner really shows a lack in low end grunt, while closing the airscrew brings bck some of the grunt around 1/8th-1/4 throttle it blubbers down low and won't idle as well an is not as crisp as I like. I'm thinking of moving to a leaner diameter needle in the same position, same pilot and dropping the main one more.

I reckon your on the money, my bike loves the 38 , falls a bit flat then has a scorching top end now with the 172, and that's just moving from a 175, the bike revs quicker through the whole rev range too.

Edit - much less spooge too

 

[Simmo737]

Cold weather and a motor that doesn't run at regular operating temp because you are lugging it a lot. Before you change your jetting drastically change your premix oil if you are using one with a high flashpoint (above 100C or 212F). I don't know about oils available in your country but here are some in the USA.
Amsoil Intercepter, Amsoil Dominator - both good
Amsoil Saber - bad
Motul 710 - good , Motul 800 - bad
Champion WP2 - good

Maxima k2 is good and easy to find, triple ester and 240f flashpoint, not super high. Same league as motul 800 with lower flashpoint. ( motul 800 is up over 500 f or something crazy) edit 485f for motul and a lower cst of 135 compared to k2 with 140, amsoil dominator 240f and 153 cst.

 

[Jakobi]

Yep Yep Simmo! Remember mines a 250, but has also had the head done down to 1.2mm squish and 13.1:1 UCCR. Been well humid up this way, with most days showing some precipitation.

 

[n_green]

It's never cold where Jake lives either.

 

[Simmo737]

Boys, boys, it was 34 at the Nock on Tuesday and quite humid, so "tropical" conditions believe me, my riding mate had just got over the flu and was sweating like a carnie with a mortgage!

 

[sweeper]

Hi

I purchased a gasgas ec300 2013 some months back. When i have been riding on low revs for some time on singletrack and trials ridning it is struggeling to rev out fully when i come out into the open. it revs but is revs unclean and does not reach maximum revs. after 3-4 runs of ful rev straights it comes back to life. have you got any tips on why this happens? i also have black oil coming out of the back of the silencer. am i running it with to much oil or do i need to set up the carbertor differntly? i am greatful for any help i can get.

More then likely you are loading the bike up due to a rich mixture as previously stated.
A couple things to check.Is the filter over oiled or saturated with moisture also previously stated..Is their water in the float bowl.Drain it into a clean clear container.If you see any water at all drop the bowl and clean it.The reed cage could have water trapped in it,doesn't take much.Is the silencer packing failing.Is the perforatef tube in the silencer broken?Some other things to look for.

 

[Nick1000]

Cold weather and a motor that doesn't run at regular operating temp because you are lugging it a lot. Before you change your jetting drastically change your premix oil if you are using one with a high flashpoint (above 100C or 212F). I don't know about oils available in your country but here are some in the USA.
Amsoil Intercepter, Amsoil Dominator - both good
Amsoil Saber - bad
Motul 710 - good , Motul 800 - bad
Champion WP2 - good

Thanks , i will check this out first

 

[Jakobi]

Nick, stock needle is too rich, regardless of oil used. The newer bikes, coupled with newer carbs just require a leaner needle.

 

[Wimpy525]

If it has the stock jetting it will be too rich. I think I have a N3CJ on the middle clip with a 175 main. What made all the difference was getting rid of the Q3. The Leo Vince made a huge difference on how the bike would rev out.