I do get crazy I can't get the bike to run lean

[Larsa]

2018 GP300 sea level in Stockholm Sweden.
99 Octane it is Sweden so it is not the same as USA RON it is lower.
2% 50:1 Motul 800 Full Synthetic
20 Celsius 68F and a little rain
Needle NEDW#1 at the top, Main jet 168 Pilot jet 40 AS 2 turns out.
Float lever 2mm lower then org. Sparkplug denso W24EsR-u
First I did run 30 minutes then I did clean silencer. Then I did run for 15 minutes and took this pictures.
This track is not so fast and it is gravel and sand average speed 27km/h 16,8mph and am not so fast driver.

I have tested all I can think of.
If I run PJ 38 I do can feel that the engine is to lean. But still drops from the silencer.
I have tested needle N2ZW at #2 still drops.
I have lower the compression by adding two extra cylinder foot gasket .15 and .50 + org .30
That because it was pining when using NEDW#2 and PJ40 MJ175 but still dropping from the silencer.

[gg3]

Hi Larsa,
Don't jet by muffler spooge it will drive you insane.It indicates poor combustion efficiency rather than jetting.
Have a quick look at your plug colour to get a general indication.If it is dark & oily there is some other issue.
My 2018 XC300 is running 175,NEDW#3,40 pilot,temp 20 degrees ,elevation 0-500m. So your jetting should be ok.
I always had oil dribbling onto the swingarm until I did the head squish.Now runs clean & heaps of other advantages.

[SS109]

Yeah, I agree with gg3. Plus, adding more base gaskets to lower your compression just killed your head squish and changed your port timing. Proper squish and the highest compression for the fuel you run leads to higher efficiency which leads to less spooge.

[Jakobi]

My 2018 has had the head setup. Still spooges a fair whack. I'll get a similar amount to the pic in the original post, but it takes me around 70kms of mostly single with a few transport sections to get it like that.

Remember the packing will also be quite soaked and any changes to jetting could take a while to clear out as well.

[Larsa]

What can I then do? On my GP300-18 it was as org one .3 gasket. And all older GasGas 300 that I have hade did have 3 gaskets .15 .30 and .5 The highest octane you can get in Sweden is 99 octane that is about the same as USA 93.
When I was using only the .3 gasket the engine started to ping when I did used NEDW #2 and PJ 40. The pinging is gone now.
What is your recommendations.

[gg3]

The Motul 800 won't be helping if slow riding.Change to Motul 700.
As Jacobi said,repack muffler as it will be full of oil.
.5mm gasket.
Air filter is clean & not over oiled I guess?
New plug NGK BR8EG
Take it for a good spin so it is at full operating temperature.
Post a photo of the plug.
How does it actually run? Does it sound rich or lean? throttle responsive or not?

[(F5)]

Spooge or the plug aren't jetting tools. A bike could be dangerous lean at one throttle position and rich at another for example and those 2 things could badly lead you astray.

I do agree a tight squish is worth achieving. I run about 1mm. But, and it is a BigButt (& I cannot lie. . . sorry) you must reduce the compression ratio back down to what your gas can cope with. Presumably what you are running now.

Read my head thread, it rambles a bit but gets there in the end.


http://www.gasgasrider.org/forum/sho...highlight=Head

[gg3]

Yeah,but a plug check will give Larsa a general indication if it is way lean or way rich,& maybe eliminate another issue as the current jetting should be close.Based on the riding terrain & style comments Larsa isn't pinning a TZ1000 on a track so should be ok.
Larsa,if you dive into a head mod read F5's thread first.

[SS109]

Originally Posted by (F5)

Spooge or the plug aren't jetting tools.

I completely agree on the spooge. However, if you do proper plug chops, and actually cut the plug open to read it, it is a very useful tool in getting your jetting dialed in.

If you really dig in to reading a plug you can tell if your main is correct and even if your midrange "jetting" is good. Look at the pic below. The plug on the left is a wide open plug chop showing the main circuit. The right plug was a needle chop about 30 seconds long in 4th gear hovering around 1/2 throttle. Notice the distinct difference in where the bands are on the insulator. If you felt the need, you could even do it at 1/4 and 3/4 throttle to see if it is lean/rich at those points if you think their is a jetting issue in those ranges.

Using plug chops, along with how easy it is to get the pilot jet correct and dialed in for best performance, you can get a bike's jetting dialed in near perfect for the conditions at that time. Keep a log book with what works at what temp, humidity, and elevation and you can make some pretty educated guesses to when those parameters change.

On actually cutting the plugs open, a 5/8" bi metal hole saw works easy as butter. From John_S over at KDXRider...

Once you start drilling you can feel it cutting and then it tapers off. That's when you've hit the first of two circlips that hold the plug together. Turn it the plug upside down and the clip falls out, drill again until it tapers off, turn it upside down again and the other clip falls out. At that point or shortly thereafter the whole ceramic part of the plug will fall out. It still only takes about 10 seconds from start to finish even with stopping to dump the circlips.

Jetting guide I always follow: Jetting Guide
Original thread on KDXRider with more info: If you do plug chops

[(F5)]

Most people contaminate a plug chop. Especially on a dirtbike.

Easy (?) on a roadrace bike where you can pin it open for many seconds on backstraight. But only if you pull the clutch at the end and push the bike back. Ride it back and you have invalidated the reading. And everybody does that.

Mostly spooge I suspect comes at low throttle, low rev situations .