Topic: '72 CB350F Choke Symptom

[fletcha221]

I have a cb350f and the electronic ignition (DYNA-S) is great. Is your bike bogging out at wide open? If you are getting backfires, you are running lean, and if you are getting 70mph, you might be starving for fuel. What color are you plugs when you pull them? If they are white, I would jump up to the next size jet. Apparently stock jets are 68's, but most have 75's. If they are 68's, Ill send you a set of 75's i have.

-Christian

[Evan]

I am not getting backfires any more after I readjusted the floats.  It just seems to peak at around 70MPH.
I just replaced the spark plugs and put in new #75 main jets.  Thanks for the offer though.

[flybox1]

fletcha221 - thought stock jetting was 75's for the mains?
My (stock) mains were 75's.  I went with 78's and its vhery nahss! 

Evan to hit 70+ you need to make a good long run downhill with a tailwind, or drop a few lb's!
seriously though, i dont know much about the electronic ign kits, so i cant answer, but if properly maintained, a points system can hang. 

[fletcha221]

Flybox,

Dude, I really don't know, some had the 68's and some had the 75's??? I'm going to be running 90 plus with mine:) Goddamed pod filters and home made exhaust.

Evan,

Have you checked the plugs since? it's usually a pretty good tell tale indication of what is going on.

[Evan]

I will check the plugs.

[camelman]

FYI, I just swapped in 80 mains to my stock (other than the 4-2 Jardine) 350F.  It bogs a bit at higher rpm, so I think the 80s are too much.  If I can get 78s, then I'll put them in.  the 80s are fine for now though.

Did you check to see if the electronic unit is set up correctly?  It needs to be set too.  If it has moved, or was set incorrectly, then it could hurt your performance.  The backfires are coming from available oxygen in your exhaust.  That oxygen is either from an exhaust leak, or due to poor combustion in the cylinder.  An exhaust leak is easy to figure out.  The poor combustion is likely due to emulsifier tubes, etc.

By the way, I got my 350F over far enough today to rub off some of the Jardine 4-2.  I'm feeling pretty good about that.  ;-)

Camelman