CB350 carb help, how to adjust needles ? ? ?

So my cafe bike is all put together http://www.advrider.com/forums/showthread.php?t=302252&page=25 and I was able to get it to run well at idle and full throttle with 115 jets instead of the 105 stock size. Half throttle acceleration is horrible though! The carb needles have no clip to adjust the height but i was told by a few guys I could shim the needles up with washers. I'm wondering how others have got past this needle problem and how things worked out. I'll be away this weekend on a dualsport trip in maine but i'll be lurking on my motoq when service allows, so reply away any help would be appreciated, I wanna ride this bike yesterday

thanks
Bill

Hey Bill, good to see you here again. Since there are no grooves in the 350 carb needles I don't now how you can move them up. I've never heard of shimming them with washers but I guess you could do that theoretically. I have a 2=1 with K&Ns with stock jets and my acceleration is smooth with a nice pull from idle up to around 7,000 rpm. But it taps out at 80 mph. I don't think it's pumping enough fuel with the extra air going in so I could probably improve top end with bigger jets. But since I do long rides I'd like to keep the fuel economy as best as possible. Have you ran it with stock jets? You just replaced the 105 secondary main jet? There are 2 other jets that you can upsize. The primary main jet 68 stock and the slow jet 35 standard. Perhaps you jets are now mismatched since you only replaced one?

Hi
You could go to #70 intermediates and #110's mains, I have kept mine at 35 slows without a hitch.

To shim use the thinnest washers you can, trial and error though

go the www.siriusconinc.com website they supply the jets $12.00 per pair,

thanks . . . i went from a 115 main to a 120 and shimmed each needle with one somewhat thick washer . . . it seems to be running well one plug is the nice brown color after a few pulls in 1st 2nd and 3rd gear . . . the right plug was fouled slightly which i found to be because of the plug wire grounding out, i found this when i got shocked through the key when starting it again after i found the fouled plug lol

do you have a pic of your shimmed setup?

bob.

no i'm sorry i do not. I do have two extra washers i could take a picture of but i don't think a picture will accurately show its size. My bike is running well now, i had to fix a spark plug wire arching problem also. I think i do need a little more adjustment in the needle so i'll try to remember the camera when I take the needles out again. what sucks is i think i went as rich as i could go in the needle already.

i'm not sure i understand what your shooting for by increasing jet sizes and shimming. i want to ask why deviate from well established standards and solutions but if your just experimenting i can see the appeal.

actually i worked on the bike a lot today and removed the shims . . . i have been chasing a carb problem that now i believe is caused by a loose primary main jet in the right side carb. i think the 35 year old o ring just ain't cuttin it any more ;D

wilbillhatchbac said:

i think the 35 year old o ring just ain't cuttin it any more ;D

Click to expand...

Well I just assumed you had rebuilt and replaced all the seals in your carbs. I recommend ordering the OEM packing sets rather than the aftermarket carb kits.

yeah i ordered oem #70 jets and i'm gonna go to a #110, stock needle height . . i think it'll be running real good then.

maybe i'll be able to go over 80mph being up 1 size in both jets . . . i wonder what the difference in roll out is between my tire and a factory one though ? ? ?

do they even sell sprockets for these bikes? actually i noticed the front sprocket looks just like the sprocket on my friends honda 300ex quad . . hmm