300 2010 carb set up for more rev.
 

Ec 300 2010 six days ,carb is 38mm asll.
My current specs are: 42p N3CJ#3 172 main.

Power is ok but is way to short on top end power,like rev limited,he stop reving too soon. Power valve work good,no freeplay.

And, another feeling is on midrange, the sound on heavy throttle is some kind deep and it comes from air box.

I have also some needles to test: NECW,NECJ,N8RW, N8RH, N3CH,N3EH. With necw was worst from bottom and to abrupt when power valve start to open,an was way to bad on fuel economy. Set up was 42 necw#3 172.

I'm down to a 170 before it would rev out with quick opened throttle, I suspect 168 would be better but I use top end so little in tight trails I don't care much. Results may vary with your gas.

What made the biggest difference was I was using a cat pipe that was gutted. I thought they would be the same and looked same from a rough measure. The original slightly flattened one really woke it up. Not the same.

Cat pipe? What is that?

The 'Cat Pipe' he's referring to are the exhausts that were supplied fitted with a Catalytic Converter in the wide part of the exhaust, obviously fitted to reduce emissions. He says it was 'gutted' meaning it had been removed, I can see how it might not be clear if English isn't your first language. :)

Someone will tell you what years they fitted the Cat pipe. I think they were usually painted black not chrome.

To help you fix your carburation problem you need to identify what throttle position is giving a problem.

For example; if you're holding the throttle wide open and it won't rev cleanly then change the Main jet.

This chart helped me understand which jets affect which throttle position...

Attachment 8283

I also found it very important to only make one change at a time, then test the result.

When I bought my bike it was fitted with a 175 main jet, it wouldn't rev cleanly at WOT (wide open throttle). I fitted a 172 then a 170 and I'm very happy with it now.

I'm the same as F5, I think it would probably run even better with a 168, but I'm happy with the performance, it's fast enough :eek: and I prefer to stay on the 'richer' side.

Good luck, Dave.

P.S. Don't forget to update us and tell us how you get on. :)

The problems updates on the thread is the must to have,if u ask me!

Sometimes I wonder if English is my first language. But I think the problem is that I type laz

My english si 1 year old :)
I know what do u want to say.... :)

When i read an thread I like to see the solution of problem,anyone want to be helpful and in the and no body knows if the problem was resolved.
I hope u will understand :)

It's no problem Adriano, I've spent many years of my life living/working in countries where English is not the first language, but 99% of the people have always been very helpful.

The important thing is you get your bike running correctly and we can all help and learn! :)

Good luck, Dave.