I've got my wifes 97 F3 apart to do the Valve Clearances. Since 1 of the shims is on BO, I thought I'd clean her carbs while I was at it.I was wanting to know if these are stock jets or if the bikes been rejetted. It does have a full V&H on it. It's also got a K&N filter in it. Here's a close-up of the jets. Let me know what you think. From what I can tell it should have either 135 or 140's in it.



Other Side

 

It's been rejetted with probably a factory pro, the stock size jets are 135 out, 138 in. You can pull the needles out to see if those have been swapped also, if they have, then they'll have a little clip that can vary the needle height, or if they're stock, then the needle will be non-adjustable

 

looks like a stage 1 factory pro jet kit.

 

I'm not sure what you mean by 135 out and 138 in. Can you explain ? I will be pulling the needles as I go through the top end of them to clean. Just waiting on the new gaskets to show up.

 

142 is a big jet for that bike even with a K&N,imo.That's SV650 size.

 

Number 1 and 4 cylinders have 135's stock, number 2 and 3 have 138's stock

 

Thanks kwong2001, I thought that's what you were referring to, but it's always best to ask. Well, I finished cleaning them tonight. I had the needles out and sure enough, they're aftermarket. They've got grooves in them for adjusting the resting height. Also in the #2 and #3 carbs they had #140 main jets.

This is from the #2 carb.


And this is the needle. The washer under it is .49 mm. I checked each of them and they're all the same.



Any feedback on the clip location and it's effects on performance ? Pro's and Cons of where it should be ?

 

That's weird, from everything i've read, the middle carbs will generally have larger sized jets than the outside ones. Did the bike have the taller velocity stacks on the outside or inside (stock should be taller on the inside)?

The way to do the tuning, first figure out the right size jets that will give you the best pull in the top end, then you'll want to select the best needle setting for the midrange, and finally, set the fuel screw for the best low end also taking into account how it runs at cruising speed. Factory Pro has specific starting point recommendations for the jets depending on the type of exhaust (stock, slip-on, or full exhaust) and what filter you're running (stock, bmc, k&n etc), the suggested starting point on the needle is #3 from the top, and the fuel screws are recommended 1.75-2 turns out.

It's really hard to say where to set it though. Factory Pro recommends to run 142 out/145 in for a competition pipe (i'd assume that means full exhaust) and a K&N. But since you really don't have any other options, just run what you got unless you wanna order other jets. I'd do 140 in/142 out, #3 on the needles, and 2 turns out on the fuel screws. Also, the way the needle works, the indents the c-clip sits in dictate the height the needle sits, higher it sits, the richer the setting and vice verca. So #1 setting would be more lean than #3 setting.

Anyhoo, hope that helps. If you need a better guide I can scan the carb tuning guide I got with my jet kit. It gives good insight on how to tell if it's rich or lean and where.

edit: one thing about the fuel screws, you need a special wrench thingie to adjust them, factory pro sells them or you can order them through honda. Oh, probably goes without saying, but make sure to sync your carbs before you start tuning.

 

Thanks for the info. I think at this point I'll leave it as status quo. As far as the velocity stacks, they're all the same size. I've got lots of things apart right now and if I start with tweeking things, I could be opening a can of worms. Once it's back together and running again I'll consider making some tuning adjustments. I don't have the special tool for adjusting the pilot screw. I'll have to consider getting one, I've got 3 bikes currently. I did notice in the shop manual what you mention on the jet sizes, larger on the inside, smaller on the out.