350X: FL to PA won't start

[camoweasel]

After kicking it for over an hour and with the help of a little starter fluid, I finaly go it to fire up. After I had it warmed up I did some fuel screw testing. Here is what I found:

-When turning the screw clockwise to lean it out, the engine will stall out at about 1/4 turn out, regardless of set RPM.
-I find that the engine's RPMS peak around 2-3/4 to 3 turns out.

Now according to most ATC service manuals, they recommend turning the screw in until the engine stalls then backing it out 1 full turn. I tried 1-1/4 turns out but the idle was a bit erratic leading me to believe it needs more fuel.
According to other sites, they recommend turning the screw out until you have reached the highest idle point, which for me was around 3 turns out.
This leads me to believe that I should try a 45 pilot jet?

[k00leo]

I have a 42 pilot and a 210 main in my 350x with 400ex carburetor. It cuts out a little at WOT, but i would rather run a little rich then lean.

I had a 45 pilot in my 350x and i could not for the life of me kick it over.

Just fool around with the air/fuel screw until it will kick over in a few kicks.

This is what i did.


I would screw the air/fuel screw in until it was fully seated, then i would turn it out in 1/4 or 1/2 increments. I would then turn the choke on, and kick it 10 times. Then i would turn the choke off and kick it 10 times. If it would not start, i would screw the air/fuel screw out another 1/4 or 1/2 of a turn.

once the bike would kick over, i would continue to screw the air/fuel screw out until it would not kick over again. then i would screw it back in about 1/2 of a turn.

This is how i got the 400ex carb to start on the 350x. I highly suggest that once you do this, you do a WOT plug chop and mid range plug chop to see if your running lean anywhere. If your running lean at WOT, up the main pilot, if your running lean at mid range, up the pilot.

I dont know if this is really the proper way to jet, but i can easily start my 350x in one or two kicks, and its not running lean at WOT. (still need to check mid range)

[camoweasel]

I have a 42 pilot and a 210 main in my 350x with 400ex carburetor. It cuts out a little at WOT, but i would rather run a little rich then lean.

I had a 45 pilot in my 350x and i could not for the life of me kick it over.

Just fool around with the air/fuel screw until it will kick over in a few kicks.

This is what i did.


I would screw the air/fuel screw in until it was fully seated, then i would turn it out in 1/4 or 1/2 increments. I would then turn the choke on, and kick it 10 times. Then i would turn the choke off and kick it 10 times. If it would not start, i would screw the air/fuel screw out another 1/4 or 1/2 of a turn.

once the bike would kick over, i would continue to screw the air/fuel screw out until it would not kick over again. then i would screw it back in about 1/2 of a turn.

This is how i got the 400ex carb to start on the 350x. I highly suggest that once you do this, you do a WOT plug chop and mid range plug chop to see if your running lean anywhere. If your running lean at WOT, up the main pilot, if your running lean at mid range, up the pilot.

I dont know if this is really the proper way to jet, but i can easily start my 350x in one or two kicks, and its not running lean at WOT. (still need to check mid range)

WOW, that would take forever to accomplish. Reason I say that is because, my engine starts easier without the compression release. That and I also have a high compression piston. I kicked for an hour straight and boy did my foot hurt!!
Ever since I had my head ported, it just seems like I've had to keep jetting up in order to make my plug burn brown. At the beginning of my build I started at a 142 main and right now I'm at a 190. So in it seems logical to me that a bigger pilot would be necessary too.
Even after I went out past 3 turns, my idle never really dropped. That tells me that the next size pilot may be needed.

[k00leo]

Unfortunately, jetting is a long and toilsome process...

If i'm running a 210 main and the only mods i have done to my 350x is the 400ex carburetor, than i agree that you need to up the main.


I buy my jets from Jetsrus. Great site, and they ship fast too!

Good luck!

[Headsup]

Ok first you have it started, You turn screw out untill it starts to die, Turn it in until it revs really high, Right in the middle of them 2 positions is on,

For the jet, i would start at yes a 45 and then maybe move down to a 42

[camoweasel]

So here's my update that I could use a second opinion on:

I installed the 45 pilot and also drained gas and refilled with fresh premium. I can now get it to start much easier BUT it is still very cold blooded. Once I had the engine up to operating temp, I performed a drop idle test. I found that my engine with the 45 pilot hits peak idle at 1-1/4 turns out; a little low in my opinion but acceptable in terms of jetting procedure. I also noticed that it starts easier without the choke lever engaged. So you would think there that pilot would be to rich but after countless chops, it seems to be fine? Whenever the bike is idling while still cold, the plug does get pretty dark BUT when warm it seems to clear up pretty good. The problem is with all the snow on the ground, it's hard to test for any deadspots in the powerband due to the loss of traction.
In a way I'm half tempted to retry the 42 only because I think half the problem was the Florida fuel?? But I'm going to wait till the snow melts to really see how it performs. But like i said, the plug does to seem to clean up running warm.
So jetting experts, what's your opinion?