no power in mid range !?! help

[Klausen]

from start to finish

2 month ago a bought a used 10month old good used bike EC 300 Nambotin 2009 60h or 2000km or 1400miles .

The test drive was OK but I can't wide open because the piston was new.
I believe the mid range feels normal.

Before I ride I wan't to check everything that can stop me in a race.

I checked the piston myself because trust is good but checking is better.
I release the complete cylinder - yes the piston was brand new.
I can't see any damages in the nicasil cylinder surface.
I hope I rebuilt everything right.
From the beginning there are some leaking - first I checked the float - I adjust it but leaking go on.
Then I found dirt in the tank and the carb - I clean it and install a petrol filter. No more leaking after this.
Then I checked the V-Force reed valve (2 reeds was frazzle) and I replace with 2 good used as a precaution.
I replace the plug BR8EG and the spark plug cap NGK LB5EMH.

My jettings are:

main:182
idle: 42
idle screw: 1 1/2
needle N1EF #1 from top
Temp: 5-12°C or 41-53°F
altitude: 120m
original pipe and turbinecore silencer

Today I test the machine the first time on a wider area.
The piston is 1/2h old.

In low range the torque is good and the engine feels OK but when I wan't to accelerate the engine needs a minute of silence and then he comes explosive.
Wide open is also OK.
But in the mide range this isn't a good feeling.

The new plug was often very wet!!!
My be a problem with the exhaust valve or a too low float?
I don't see a air leak.

Where can I looked for the problem?

 

[GMP]

Remove the right hand PV cover and observe the PV operation with RPM. My bet is its a sticky PV.

 

[kendunn]

first thing I would do is get a new plug and get in an open area and run it in the midrange for as long as you can then shut the bike off and check the plug and go from there with your jetting. I think if the power valve wasn't opening your top end should suffer the worst. I bet you need to replace your needle with a bit leaner one, that seems to be an issue with a lot of these bikes. Do a quick search and you can find a lot on the needles that work best.

 

[GMP]

If its blubbering yes, but if its a bog then check the PV. Reason is also because he had the cyl off, so an assembly problem is always a possibility.

 

[Gasgasogeros]

the needle N1EF is the problem for low end horsepower take a jdjetting for find the instant trothle response

 

[Fred1956]

If its blubbering yes, but if its a bog then check the PV. Reason is also because he had the cyl off, so an assembly problem is always a possibility.

ahhh Yes !

 

[Klausen]

Today I ask a GG dealer.
The PV and carb and plug and s.o. work very well.
You don't believe what the problem is, it is very strange and appears only in Germany.

 

[iancp5]

You haven't got a catalyst exhaust on it have you? Had one on my 200 and it was weird until I changed it.

On the older 300's N1EF on no. 1 would look a little lean to me. I used to run either 38P, N1EF on 2 or 3, 178M. That's leaner on the very bottom then richer then leaner. But ............... later bikes may be different. You didn't say where the plug was getting wet in the throttle range.

 

[widebear]

Your jettings crap, Scheisse, but i'm thinking it's also got something to do with your cylinder height, to many base gaskets?

 

[Gasgasogeros]

my have the same symptom wiht 0.15 base gasket , mabe i think need more
On september at greece wec i ask the spain factory team about the jetting they say pilot 42 needle 1NEG at midle and main 178

 

[Klausen]

ou haven't got a catalyst exhaust on it have you? Had one on my 200 and it was weird until I changed it.

no I have only the open pipe with the nickel surface

On the older 300's N1EF on no. 1 would look a little lean to me. I used to run either 38P, N1EF on 2 or 3, 178M. That's leaner on the very bottom then richer then leaner. But ............... later bikes may be different. You didn't say where the plug was getting wet in the throttle range.

My dealer recommend a N1EG - the plug becomes wet before when the GG don't want start - now the plug picture look OK.

Your jettings crap, Scheisse, but i'm thinking it's also got something to do with your cylinder height, to many base gaskets?

Yes I know I will try a DDK needle.
What is your choise?
The cylinder height could be also a problem - good idea.
The former owner fit 3 gaskets appr. 2mm.
I have to check dimension X.(Dimension „X“ is the dimension from upper edge of piston to upper
edge of cylinder with cylinder under low tension and piston in TDC position.)
How much is this - don't find it in the workshop manual.

On september at greece wec i ask the spain factory team about the jetting they say pilot 42 needle 1NEG at midle and main 178

This jetting should be OK in this hot conditions (46°C - 114°F) and altitude 70m.

 

[widebear]

Make your squish corrections using these specs by Ron. Do it using ony gaskets alone, without cutting the head.

http://www.gasgasrider.org/html/measuring_squish.html

 

[jefgil123]

Yes, it is very easy to try the different Carbuerator Needles people
use in the "Jetting" section of this website. My personal one is "CCK"

 

[dank]

Yes, it is very easy to try the different Carbuerator Needles people
use in the "Jetting" section of this website. My personal one is "CCK"

what do you have your clip at? ive got a cck and im still gettin a flat upper middle range. still need to play with the main too, but that mid section is driving me nuts! the cck was reccommended by ron btw. rght now mines on the middle clip.

 

[Jakobi]

This is the exact same problem I am facing. N1EF on top clip. 40 Pilot, 175 Main.

Runs nice from idle to mid, then burbles and carrys on like its drowning in fuel, clears its lungs and hawls right through the top.

Its not too bad in the open stuff where you can clear often but as the trails tighten the problem compounds.

Have a N1EG on back order to try on 3rd clip, and a N3EG here that I may also try.

Keen to know if you get it sorted

 

[GMP]

I think the CCK is too lean for the 250. Try working with a DDK,DEK or best yet JD Blue from the PWK38 generic kit. Also work with a #7 slide, much more suited to the 250 than the #6 that might be in your '03. Cruiser and I both had '03s, and they were a bit flat in the mid compared to older and newer bikes. What really woke up both was swapping the CDIs for pre '03 XC250 CDIs. A 200 or MC 250 CDI would work as well.

 

[dank]

i had my slide cut to a number 7, and put in a cck as par rons recommendations. when i get home next time i may do some tinkering and move the clip up a notch. i just wondered what jefgil had used.

 

[GMP]

Get a copy of JDs spreadsheet. Enter your current jetting as a base, and then a couple others like needle taper (series), clip position, etc. and compare the relative change in the area of interest to what you are experiencing on the bike. You get a real good visual on what to expect with your planned change and if its the right move before you try it. Good tool.

 

[Jakobi]

Get a copy of JDs spreadsheet. Enter your current jetting as a base, and then a couple others like needle taper (series), clip position, etc. and compare the relative change in the area of interest to what you are experiencing on the bike. You get a real good visual on what to expect with your planned change and if its the right move before you try it. Good tool.

JDs spreadsheet doesn't have the specs for the N1EF in its database. Which in turn doesn't help anyone.

I have just changed from the N1EF#1 to a N3EG#2
40 Pilot
175 Main

Idles much better. Snap and response from the bottom into the mid is incredible. However it feels like it could be signing off a bit early. Maybe too lean on the main. (Will have to plug chop some time).

Down the road I'm not sure if its making more power than it was, but it sure is transferring between on/off the pipe much more cleanly.

 

[iancp5]

JDs spreadsheet doesn't have the specs for the N1EF in its database. Which in turn doesn't help anyone.

I think it does.
Have you checked you're entering it correctly? N1 - E - F