Help me Jet my Carbs

[jryftc]

Hello...so I got a jetting question. Just to cut through as much trial and error at jet size as possible..

Got a 1978 CB550 with PD46C carbs. Everything on the bike is completely stock, the pipes, the carbs, the settings in the carbs the air box. However my air box adaptors don't fit as tightly as I'd like, and replacements are a lot. Plus when I gotta pull carbs it becomes more annoying. Figured with pods, there will be more space, and maybe with some sick performance pods my bike will even run better? Maybe...

So my question is does anyone know a good pod and jet size for my make and model that's safe to say if installed my bike will run pretty well. Trying to keep it as a daily rider, so I don't wanna be pulling my carbs 4-5 times but if that's what it comes down to that's that. Any two cents on this is appreciated, thanks.

 

[redwillissuperman]

Pods do not "typically" increase performance. Keep the air box on your stock bike and fit a custom or stock replacement high flow air filter. Look at Unifilter or K&N. There are also other companies that would allow you to make a custom panel foam air filter using bulk material. However, a uni or K&N filter will flow much more air than you need PLUS
the stock air box has built in Venturies.

I don't see why the rubber Venturi boots are loose, but you can add a wrap or two of 1/4-wide tape to the flange of the carb, under the boot. Usually the clamps will take up any slop.

Removing the air box is not a beginners move and eliminated the air charge tuning that is required on stock carbs. Most likely you would see a performance Decrease

 

[barnett468]

.
there is no way to accurately guess jetting for you bike other than it will run leaner so it will need bigger ones . . a guy installed just pods on his stock suzuki and had to go up around 10 sizes.

my approach would be to ride it first before you install the pods and do a few accelerations by cruising at 3500 rpm in 3rd gear then open the throttle all the way until it is around 700 rpm from red line.

also, from a stop, accelerate normally up to 20 mph and see if it has a flat spot/hesitation.

post photos of the spark plugs.

install new plugs.

do the same ride test after you install the pods.

if it had a hesitation from a stop, go up 1 size on the pilot jet and test again . . if it still has a flat spot, lower the clip on the needle 1 position and stop there for now then do the same test

next, go up 2 on the main jet and repeat both of the tests, then post more photos of the plugs.

post all the results for EVERY test.

jetting is easy but it can be a time consuming process . . failure to do it the way i described or something similar, might cost you a lot more time and money in jets.

this test works best if your bike is currently properly jetted . . if it is not then we have no idea if t is currently too rich or too lean and can only take a best guess based on the current plug color.