anyone have a fcr jetted for this hot cali weather?

[squintz]

Hey guys I'm building a 270 big bore and would love if someone with a similar setup could chime in and get me close.

Heres my setup right now (i believe its stock)

needle: OBEP Q 4TH clip (also happens to be middle)

pilot: 42

leak: 80

main air jet: 105

Main: 178

starting jet: 72

Elevation: 1000ft

Weather: 95+

If anyone could take a min to explain what things need to happen when you up the bore size that may give me enough to start.

or maybe....

When it gets hot you need to go up/down in ____________ jet

When you go up/down in elevation you need to go up/down in ________ jet

Its also kind of hard to find the names of the jets so I attached a pic of them and the names

Thanks fellas!

Also looking for nor cal riding buddies! I live right by georgetown and mammoth bar!

Edited July 9, 2013 by squintz

[FORMA MOTO]

When you go up, air is thin, so you are rich until you re-jet.

Same with heat and moisture. The more you have, the richer you get, so you have to re-jet.

When it's cold, air is dense, you are lean until you re-jet.

It would be great if you told us the year and model of your bike...........

[squintz]

Shoot didn't realize I forgot to put 07 yz250f. So when its hot air is thin then you want to limit the amount of gas so assuming the pilot is right id need to maybe go down on the main a bit and move the needle clip towards the bottom (5th position from top in my case?)

Is that the proper way to lean a bike out or do you need to mess around with the start jet and main air jet and leak?

Edited July 9, 2013 by squintz

[FORMA MOTO]

First off, there should be no reason to change your jetting just because of a larger bore.

The bore itself does not create a lean or rich condition.

If you are having specific run issues with your current jetting, then we can discuss.

If you have not modified your accelerator pump linkage, changed to a 55 leak jet, and adjusted your apump linkage, you should do that.

Also a fresh oring on the fuel screw.

I don't think that is the stock needle. Almost all YZ needles start with N.

Look it up in the Yamaha parts fiche.

[squintz]

That was basically all the information I was looking for. I thought Id have to open both the air and gas jets up to allow more air and gas to pump in.

Ill def be going to a 55 leak and doing the oring mod.

Your time and assistance has been much appreciated. When I kick this sucker over in a few days Ill report back.