CB350 Carb Jettind Advice

[J.K.L.P]

Hi all, I've been lurking for a while here trying to gain as much knowledge as i can but i really need your help.

I've just finished building a '72 CB350 (will post pics soon) and am now trying to tune it. The bike ran really well with the stock air box and mufflers on it but since then i've installed some DCC velocity stack and emgo shorty mufflers. No other changes have been made to the engine.

While acceleration under moderate to hard throttle it seems to be braking down around 4500-5000rpm. So i take it i need to change the jetting in the carbs to suit the new setup. Can anyone offer some ball park jetting sizes that i should be trying? Any help would be much appreciated.

 

[Big R]

I'm not saying this to be a jerk- but that is a fairly recent topic and a search should result in a better answer than I could give.

A guy that races the 350's said that very minimal changes were needed in jet sizes (if any). So you may just need to bump the mains up a size or mess with the mixture screw.

 

[J.K.L.P]

No problems at all Big Rich. I've searched and read a number of posts regarding to jetting and know that the topic is covered probably once a week but still was unable to find what i was looking for.

If i remember correctly the main jet standard is a 115 so should i be changing up to a 120? Or should i be buying a 120 and a 125 and then playing the mixture screw to get it right? Thanks for your patience.

 

[Big R]

Honestly, I've never owned a 350, and only helped to wrench on them every so often. So I really couldn't tell you what sizes are stock. Once you find out, try just one size larger.

Stock carbs, right?

 

[J.K.L.P]

Thanks for your help. The carbs are stock