cb350f Carb Question

[trsears]

Hi Everyone

Im currently getting stuck in to my first build of my first motorcycle, really am a little over my head! The bike is not fully running, but enough that I took it up the street the other day, and at about half throttle, It spluttered and would not pull at all, when I changed gear it was fine in low revs but then again spluttered at half throttle.

Immediately assumed that it was a carb problem, and was expecting to have to do a rebuild of the carbs with new jets/needles etc. I finally got round to taking the float bowls apart today and i was pleasantly surprised! I was expecting rust and gunk everywhere. Basically i just want to know if anyone thinks that a rebuild is what it needs, or whether I can save the money with just carb cleaner. Could it be the float levels that were causing the spluttering problem?

It seems the P/0 may have already done what I am about to do, but as you can see from the photos, carb #1 (I think its 1 and not 4) has a little black gunk in it but not too much. Am I being over confident in hoping I dont have to do a rebuild cause I really am in over my head there.

Thanks so much for any help in advance.
T

 

[SONICJK]

Give everything a good cleaning.
Spray carb cleaner and compressed air into every hole repeatedly.
Remove all the jets and make sure they are clear.

How is the bike setup? Stock airbox and stock exhaust? If not then you probably need to rejet.

 

[trsears]

Give everything a good cleaning.
Spray carb cleaner and compressed air into every hole repeatedly.
Remove all the jets and make sure they are clear.

How is the bike setup? Stock airbox and stock exhaust? If not then you probably need to rejet.

Hi @SONICJK, thanks for the reply,

It is now running pods, and I just bought a Mac 4 into 1 exhaust system that I havent got round to fitting yet. I plan on leaving the baffle in on the Muffler though, and on Dime City Cycles they say that with the baffle left in, I will not have to rejet.

If this is the case, would I be looking at larger or smaller jets? Apologies for being clueless here!

 

[SONICJK]

What brand of pods?

With pods and a mac exhaust you will absolutely have to rejet.
You'll need to go up at least 1 size on the main jet, probably more.

Spend some time on here reading up about jetting, how to, why its done, etc. You'll learn a lot

 

[trsears]

What brand of pods?

With pods and a mac exhaust you will absolutely have to rejet.
You'll need to go up at least 1 size on the main jet, probably more.

Spend some time on here reading up about jetting, how to, why its done, etc. You'll learn a lot

Will do some reading thanks so much. I have done some reading and understand why its done, just need to dig into how etc a little more. I was worried I would have to send them somewhere to have a refurb so sounds like with a good clean they will be ok.

Thanks again. P.S. Love the cb400f! beautiful build

 

[SONICJK]

Thanks man,
Basically all you're going to need to do is make sure they are absolutely spotless.
And then you'll just pull out that middle jet in each carb and replace it with a size or two bigger. Very simple.
I dont know too much about the proper jetting on the 350's or I'd tell you what jets to try.
I think they came stock with a 70, so you're probably looking at 75 or 80 mains.

My 400 is running 88 mains and 38 pilots with K&N's and a fully open kerker exhaust.

 

[trsears]

Thanks man,
Basically all you're going to need to do is make sure they are absolutely spotless.
And then you'll just pull out that middle jet in each carb and replace it with a size or two bigger. Very simple.
I dont know too much about the proper jetting on the 350's or I'd tell you what jets to try.
I think they came stock with a 70, so you're probably looking at 75 or 80 mains.

My 400 is running 88 mains and 38 pilots with K&N's and a fully open kerker exhaust.

Ill read into stock jetting on a 350, thats great info though, really helped me out. The pods are nothing special, so perhaps with the money i saved on a refurb i could look into new ones. Thanks again man.

 

[SONICJK]

No problem man we all have to learn at some point

I switched from cheaper pods to K&N's and it made a very noticeable difference.
Look at Amazon I think they were under 70 shipped.