Is there any difference between the two besides that the kit gives you a lot of different jets and the needle or are the jets the same thing?

 

Jay,
while not a honda guru, or EX owner, I can only tell you what has worked for me & I found out in 2 yamaha street bikes and the Kawasaki Prarie 650..so take it for what it is worth..

I know you asked
<<Is there any difference between the two besides that the kit gives you a lot of different jets and the needle or are the jets the same thing?>>

let me see if I can answer based on my experience & what I did on all the above machines..

1) is there any diffrence between the two?....well in theory, no, but in function yes..you see it seems like all the carb makers rate their mains a little diffrent than the jet kit companies..Mikuni rates on flow, Dynojet rates on Diameter (mm's--a 120 is 1.20 mm)
see
Terry Campbells V max site for a comparison between Mikuni jets and Dynojet sizes

2) yes the jet kit gives you a pretty good range of sizes, from small to big, but they are not rated the same as OEM..

3) The jet kit gives you adjustable needles, or ones that you can easily..note I said easily raise the needle position and some shims for 1/2 needle position adjustment..but the taper of the needle is more radical than the stock setup and works with the jet kit jets mainly..(there is a couple of quirks to this..they want you to use DJ needles with DJ jets..)

4) what you are really paying for is someone to take the time and dyno test and get you close if not right the first time..not the parts themselves..

5) most all of the jet kits use the stock pilot jets, that is why the needle taper is diffrent..to compensate for it..


CAN YOU DO WITHOUT A JET KIT?
well contrary to popular beliefs, as a lot of kits are sold..I think YES..if you find out what sizes are in the kits, and have a fair idea of how a carb works..as far as what circuts control what..

can you deal with the non adjustable needles..well I can,,they can be shimmed for about 1 1/2 clip position anyway.. but it is preference..

I had a good Idea of what I wanted in the V star 650, and the Royal Star 1300..and the prarie 650 so instead of a jet kit, I did mods to the airboxes to relieve restrictions, put more free flowing filters on, and increased the size of the stock jets( and pilot jets) to what I needed, I shimmed the stock needles, and on the street bikes I relieved the exhaust restriction somewhat..

DID I Still have to play with it and fine tune it?...YES..but did I learn something..SURE I DID..Did I save some $$..well I think I did..considering that the ket kit was 80 bux and the filter was 50 for the v star, the kit was 95 and the filter was 45 for the royal, the filter was 21 and the kit was 40, snorkle was 50 for the prarie 650..I ended up about 100 bucks total, filter and jets for the royal, 65 for the v star, and 77 for the prarie, and they run a lot better..

it all depends on how much you like to tinker, and if you have an idea of where to start.. I'll tell you this back in my MX days..every one just carried about 4-6 mains with them, or had acces to them, and maybe 2 pilots..there were no "jet kits"..

sorry to be long winded, but I call it as I see it..

 

thanks for the info

 

I trimmed the intake snorkel, put on a K&N filter, and removed the spark-arrestor on my 400EX... those modifications in theory, would only make a difference at wide-open-throttle... so the only thing I did was upsize the main jet, $4.... saved a lot of money

now if you went with a full pipe system, and removed the airbox lid completely, then you probably need a full jet kit

 

Buy single jets and filter. saves money. Jet kit is wortless and overrated. Jets are 2$ a peice. Buy 3-4 jets and a K&N it will only cost around 50 instead of like 80 or 100 for the whole kit. I made the mistake of buying the kit. Total waste of money.