Lunchbox install with unknown jet sizes

[el_brio]

I have a 2001 I purchased with full aftermarket exhaust installed and jetted by prior owner.  I slapped a lunchbox on today and the bike is running pretty good but is surging or maybe not just 100% smooth when I'm wringing it it out starting at around 8K rpm.  The idle seems fine and the mid seems fine.  Anyway the bike seems a bit louder and the power seems a bit better, but werher or not it's worth taking the carbs apart and rejetting them is another question.  Since it seems to be just a little lean, is this something that can be corrected with a couple of washers on the needle or will I need to go up a size in the main jet?  Can the needle be shimmed without taking the carb apart/off the bike?  I talked to the previous owner and he said he thinks he has 22.5 pilots, 62.5 mids and 137.5 mains with 2 20/1000ths washers on each carb.  I am hesitant to take the carbs off and dissassemble them because I've never done it before.  Anyone offer any advice?  Based on the recommended jet sizes on the wiki, I'm not sure if his recollection of the sizes are correct... seems pretty smal for the mid and main but it runs well with the stock airbox.

[Watcher]

Changing intake/exhaust ALWAYS needs a rejet.  Especially intake related.
Running lean leads to burnt valves and more, you don't want a lean bike.  If anything, running too fat is better.  Fouled plugs and such can be cleaned, burnt valves can't.


Don't be intimidated, carbs are easy.  The hardest part is getting the filter on/off but since you moved to a lunchbox it's a non issue.

You don't even have to disconnect the cables if you really don't want to.  Just gotta flip the carbs over and get the bowls off.
Just disco the fuel lines, drain the bowls (brass screws on the side), pull the tank, yank the carbs off, open the bowls, switch jets.  Easy peasy.
There's even a pictorial on the main page, and the wiki takes the guess work out of picking jet sizes.

[el_brio]

One thing that isn't clear to me is needle shimming vs jets.  Is needle shimming for fine adjustment and jets for bigger steps?  The guides I've seen haven't been clear on this.  Also, is it a good idea to have extra seals on hand before I crack open the float bowls?  Anything else I should buy other than jets and seals?

[The Buddha]

Shimming the needle is less than 1/2 a jet size and mainly affects 1/4 to 3/4 throttle. Basically you cant just shim your way out of this.
Jets - Pilot controls 0-1/8th, float level controls 1/8th to 1/4, 1/4 to 3/4 is needle, with mains working gradually from about 1/2.
If your bike had a mid main, it may help you avoid shimming the needle.
The jetting formula with jets and shims was essentially developed after O2 sensor runs where I noted the thing getting lean in the 1/4 to 1/2 range and getting better past 1/2.

Anyway K&N and pipe is easy to rejet, regardless of year, and you are saying PO jetted it, do you have the original needle If so, I have a feeling that they used my formula. Then you just need 1 - the main jet, so post details, and I might sort your jetting out.
If you have a DJ kit, you cant use my formula. Gotta have the DJ larger jets.
Cool.
Buddha.

[el_brio]

Is it a mistake to open the float bowls without having extra gaskets on hand?

[The Buddha]

Is it a mistake to open the float bowls without having extra gaskets on hand?

Float gaskets usually survive several disassemblies, unless you gorilla them.
And you need 147.5 mains - sorry I missed the part about the jets he used. 22.5 is likely to be too rich but if your take off is fine, you can work with it, 62.5 will alleviate most of your mid range issues, and that with the shims under the needle get you to the sweet spot. You're too low in main jet size to be  able to compensate with a shim, basically you may be able to make up 1 main jet size with ~2-3 washers, but you're 4 down, no way, you can slap in 10 washers and screw up the near perfect lower mid range or put in 147.5 and never have to even think twice.
Small round slotted mikuni 147.5, K&L part number 42-1950. Cycle gear would sell you a pack for $15 or there abouts, or I'll send you a set for $10 shipped inside US.
Cool.
Buddha.

[el_brio]

I will pull the jets out and see what they are when I get home.  The size is etched on them correct?

[The Buddha]

I will pull the jets out and see what they are when I get home.  The size is etched on them correct?

You may have to clean them to see what it is, but yes.
Usually mains will survive a removal and reinstall, if it wasn't tightened to heck and back, but pilots are probably likely to get more damaged - and I never reinstall if I remove, but that's just me. Visually check before removing, likely you can read it right off the thing.

Cool.
Buddha.

[el_brio]

Ok.  Mains are 137.5.  Mids 62.5.  Pilot 22.5.  I didn't see your post so I took them out and cleaned them.  The needle has 2 washers on long end of the needle that mic at .4mm and one on the short end that mics at .5mm.   (Edited because at first I only saw one washer).  Should I throw another washer on each side before I put it back together to see if it helps?

[el_brio]

So the washers that were on the needles were smaller than m3.  I stopped at Ace and got 4 m3 washers and swapped them for a total shim of 1.2mm (was .8 before) just for kicks.  Got everything back together after getting down the street my engine died.  Came back and discovered I routed the fuel lines wrong.  Fixed the fuel hoses and now it starts and idles really nicely.  I could only run it down the block a couple of times because my wife left me watching the kids.  I'll take it for a proper test ride tomorrow but I believe Budda when he says that I'll need new jets.  Budda, how do we go about setting up a sale?  It would be great to get what I need by next weekend.

[The Buddha]

Paypal me - watch your PM.
Cool.
Buddha.

[el_brio]

Ok.  Got the jets Buddha.  Thanks for the fast shipping.  Put them in last weekend.  Unfortunately here in Chicagoland it rained all weekend.  I got out for a few miles and the mid/full throttle seems fixed.  However, I think the idle is too rich.  When I started it, it would fire right up  when cold with no choke.  Any choke added would bog it down and kill it.  Tonight I took it apart again and checked the gas air mix screws.  They were like 4.5 turns out which is way to high from what I have read.  I turned them all the way in and backed each out 3 turns.  Bike starts and idles fine and seems better.  About half choke causes it to idle high but anymore and it will kill it.  The bike is kinda warm now so it is hard to tell.  From the little testing I could do in my garage, when I throttle on slowly from idle (set at 1.3k rpm) it seems a little rough until it hits 4k or so and then it seems to smoo
th out and sound a lot sweeter.  Not sure how I go forward from here...  do I chop and pull the plugs at idle to read the plugs?

To summarize right now I am at:

Full V&H exhaust
K&N Lunchbox
147.5 main
62.5 mid
22.5 pilot
Air fuel mix screws set to 3 turns out
2 m3 washers on each needle for 1.2mm shim on each

Thanks guys!  Almost there I think.