Jetting EC 125

[Noobi06]

Hi, I am confused. Stock Jetting for GasGas EC 125 2005 is 185 main jet and 45 pilot according to parts manual and 35 pilot according to regular manual.
The previous owner had a shit ass silencer. I bought the bike in parts and changed the silencer to a husqvarna 125 FMF Powercore silencer. I did NOT start the bike with the previous silencer so I do not know how it is running with it but I can tell that it is running really rich with the FMF silencer.
Its running rich through all the RPMs which confuses me since the main jet is literally smaller than stock.
Am I right or wrong that I will loose power compared to stock if I have a jetting thats smaller than stock? Doesnt it mean less fuel than it does have OEM?
Float height is good. Should I try to start it without a silencer??
Thanks

 

[(F5)]

A change in pipe can make quite a difference. The muffler, not so much. As long as it is well maintained it will be fine. Don't focus on it.

Find a big surface like a garage wall. Write in big letters. My 2 stroke carb jetting is affected by throttle position, not revs.

I'm not being a dick, hear me out.

It is theoretical possible for a carb to be rich off closed. Lean in mid position. And rich wide open again.

Or any other combination.

Go ride the bike, come back and consult the wall. It will change how you think about things.

Word on jet size. The right one will produce the most power. Too big or too small will lose power. Too small has added risk that it could cause overheating. Lean can melt an engine.

Beware of Too small pilot jet. Closing the throttle you are asking for a lot of flow from that jet.

People with the wrong needle often go too small trying to get it to run right at low opening.

45, 42, 40, 38, 35. That's 4 sizes! I'd check parts book.

Ignore spooge on muffler or plug for now.
The wall is your friend.

 

[Noobi06]

Okey. I was thinking of just changing the main jet for now and getting it it to run good on higher throttle. After that I will play with pilot jet and to be safe, I will keep the bike overall slightly rich