Help VJ21 carby jets

hi guys just in the process of doing the carbs on my RGV....its a VJ21 1990L with the 34mm carbs(mikuni VM34SS)the id no on the r/h/r of the main body is 12C30 & directly under that is 091 on striping & cleaning them ive found the L/H carb has a 250main & 65power jets while the R/H has 260main &75power jets correct me if im wrong(and yes i also believe that 270mains are the recommended) but i believe the slightly smaller jets will sqeeze a little more power out, but i believe who ever has done the carbs before me has put the jets in the wrong carbs as i think the L/H should have the 260&75 & the R/H 250&65 any thoughts on this? also chasing parts for them in particular needle & seats which are no longer available from Suzuki although the VJ22 needle & seats are(they are diffrent part no's)but does anyone know if they will be ok to use? or were i can get them from? thanks in advance for your thoughts

 

Hi kiffsta, & thanks for the reply, yeah just standard exhaust, the only thing im a little not sure on ,unless im getting confused but the 260main & 75 power jets were in the R/H/S with the 250 & 65 in the L/H was sure the power jets were in the correct sides(which looking at the manual u posted they are not)but im sure ive read somewhere that the bigger main should be in the R/H side(which makes no sense as the L/H has the bigger P/J) ahhh maybe im just confused.....thanks again for the reply

 

any thoughts on if the vj22 needle & seat will work in that carby? my own feeling is i think they would & see no reason why they wouldnt, even to the point they run the same sealing oring

 

cheers maelstrom, thats VJ22 (22D00) the VJ21 is 13370-12C20-000 or 13370-12C10-000, although i can see no real reason that i can not use that part, Suzuki Australia has it but they to can not tell me if i can use it, all they will say is the part no is different so it must be a different part, although from all my investigations i think its the same, it even takes the same mount/seal o'ring but in saying that the o'ring has not changed part no's, it may be a $100 gamble i have to take......thanks for your reply maelstrom.

 

thanks for that link maelstrom ive just had a good look through it & it does seem that 13370-22D0 is listed as an updated/superseeded part so its the only option i have so i will buy them.....the other interesting thing is the main jets & power jets.....it does appear for that parts listing that my P/J were installed correctly but my M/J were in the wrong side, so i will swap them,thankyou once again that has been some valuable information for me.

 

now i also wonder if i also need to swap my needles over , mmmm the research continues.

 

just an update with the needle & seats, took the punt & ordered the VJ22's (13370-22DO) from Suzuki, as stated above from the evidence i got from maelstroms post ,yes the are a direct replacement but no they are not identical, but yes they will work & even though im not up to the testing stage i believe they will work beter, external dimentions of the seat are the same so they are a perfect fit for the carby body, internal the needle is bigger as to the seat(so im thinking they will just allow the fuel into the bowls at a faster rate)

 

and sealing o-ring for seat is same parts no for VJ21&22

 

now im up for needle inspection & research, can some one correct me if im wrong but from what i can gather from reading bits an pieces from diffrent posts, lowering the clip on the needle moves the needle up makeing for a richer setting & raising the clip on the needle moves the needle lower for a leaner setting ? am i on the right way of thinking here?

 

just an update on the carbs, no matter what i did-countless hours of tuning & test rides, could not get it to run correctly on the 250/260 MJ or for that matter on the 260/260MJ(this is the bike original settings 250/260MJ from when i bought it in 93 & has run faultless in this configuration up until recently) ive eventually fitted 270MJs & after a bit of tuning & testing im 3turns out on the air screws/jets & thats where it runs most responsive & faultless 2turns its really sluggish 2.5turns is fair 2.75 is better & 3 its a cracker right from idle to redline with heaps of bottem end(even though factory suggests 1.75 turns out) i geuss it may be a little lean but engine temp remains stabile & at the same temp it always use to, so im going to trial it like this & see how it goes.....now its off to address the cracked power valve i found when looking for this performance issue(its cracked a piece off the ring which gets held into the cylinder with the phillips screws, even though its no where near were the screw locks it into the cylinder....mmm strange)

 

yeah i do understand what u are saying as the bike has always run good with the 250/260MJ combination, but i just cant work out what it is & its now running faultless on the 270/270MJ comb, hasnt been rebuilt since 2004(but its done bugger all since 04) have checked compression & it checks good(from 4 kicks w.o.t warm engine it gives 118psi top cylinder & 115psi lower cylinder....it may well have even gone higher i just stopped kicking on the 4th kick@118psi/115psi as i was more than happy with that)from memory when it was freshly built in 04 i think it had about 135psi...(checked with a freshly calibrated snap-on digital compression test gauge)

 

have tried both fuels 94+10%Ethanol as well as 98 makes no difference, have changed needle & seats have adjusted float levels nemerous times rangenig from 7mm to 9mm, im thinking next i will try emultion tube needles(as thats about the only thing i havent tried or replaced) other than that it may be something in the carby bodys themselves.

 

im not sure, any suggestions on how to clean them?- will clean mufflers & chambers(poor fuel down them & light them) i really dont think that is the issue though as it should do it no matter what jets i was running.....i will repair the faulty power valve & when doing that i may as well pull the exhausts completely off & clean them + will aid me when re setting the P/valves ,i will also try a few other things to see if i can over come the issue(although i am in 2 minds as it is now running well on the 270M/js but the other half of me still wants to know as the bike has run for the last 20+ years on the 250/260M/j combo)