"Carbonite" CB350 Cafe by first time builder

Bad mounting spot for my taillight, broken after 2 rides

xb33bsa said:

the tailight wont last long where it is that is where the tire goes when you hit a bump

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lol, guess what happened on my second ride out! thought it would last a little longer than that. thanks for trying to prevent it though. Chalking it up to fist timer mistakes.

Problems with carb tuning

having some major problems with carb tuning. or should i say, created problems. working on diagnosing where I'm going wrong. looks like at around half throttle I'm sluggish and then the main jets kick in. was working fine and didn't mess with the main jets, just the pilot screw. air intake and exhaust are the same, so i'll slowly start figuring it out.

warmed up the bike and then had the throttle at half when i flipped the kill switch. pulled the plugs to see if i was rich or lean. looked normal to me. but... first time diagnosing plugs. i was comparing it to all this pics on the web. to be honest, looked normal, maybe a little white. but no deposits. so if anything ...maybe I'm running lean? might have to take it to someone with more experience to help me understand.

Forget the plug chops. Those probably won't help you much if you don't tune bikes all the time and know what you are looking for, the pics on the net are only easy to read if you have something drastically wrong with your bike/tuning.

Couple of questions:
Carburetors are clean of all debris correct? Are you SURE? Move to the next question if yes...
Does it idle? If so, did you synchronize the carbs? If it idles, but you did not synchronize, do NOT continue to the next bit of info, unbalanced carbs can cause all sorts of "symptoms" that are not curable until you sync the dang things!

Your pilot screw adjusts your fuel or air mixture (depending upon each carburetor's design). What are the stock settings for this bike (see table here http://oldmanhonda.com/MC/DataTable.html) So for your idle to be at stock settings that screw should be 3/4 to 1 turn out. You have modified the intake side and might need to bump it up to 1.25/1.5 turns out. That said, this screw will only cause you headaches from 0-1/8 or 1/4 turn on the throttle. So when you are accelerating from a stop, you would have some hesitation until you got to the mid range, and then it would be fine from the midrange to high end.

If I read your post wrong, forgive me, but it seems that if you are at half throttle (mid range) and you are giving it more gas, it hesitates and then seems to come to life at the higher end right? That would tell me it's got too little fuel in the mid range, and you would want to lower the clip on your slide needles. This pulls the slide needle out of the way earlier allowing more fuel into the carb throat at mid/high throttle.


Neat project, most will tell you things that are "wrong" with your bike. Some are just couch engineers, while other comments aren't really negative, it's just that they learned from their own/other's mistakes and are trying to help. As you found out with XB33bsa's comment about your poor tail light Keep at it.

Do a search on why cheap pods don't work.
http://www.dotheton.com/forum/index.php?topic=45863.0

Re: DL link for wiring diagram broken up into separate systems

Toxic Motorwerks said:

Saturday, not a problem. I'm more that happy to. Here's a link to a Google Drive folder I made public.

bit.ly/1971HondaCB350WiringDiagrams

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Link seems to be broken, but I really appreciate it nonetheless. Sorry about your tail light dude! Live and learn bud I'm sure I'll be learning the same way too!

even if the pods are not obstructing ports on the back of the carbs, they're still crap. did the original airbox have some sort of rubber adaptor with a trumpet shape? reuse it with a decent pod - k&n or foam style. you can even extend the inlet with some tube to make it go better.

cv carbs can be quite frustrating, especially as you can't/don't control the slide. generally being too lean on the needle means you can't get them to full lift and on to the main jet. so you can't tune the main jet, which is where you usually start. and, even at wide open throttle, it won't necessarily be on the main jet until higher in the rpm range.

you also need to think of what you're doing in terms of upsetting the upstream or downstream flow. allow more air to the inlet and you lower the vacuum across the carb, leaning it out. if you open the exhaust you can make them richer, the opposite of what most will expect. and you can also make them do wacky things. people often open airbox inlets, then start taping the hole up to find the point at which it makes the most power. can be a useful tool, or help to understand what you're doing to screw it up.

if it won't rev, just keep lifting the needle until it does. i've seen 6mm spacers under the clips because they ran out of grooves. once you can get it through the midrange, you can start tuning the main.

if you can get a jet kit for it, that's a great start as the needles are much richer. if you can't, see if you can adapt something. the softer slide springs generally make them more responsive, but it's the needle which really helps. the springs can also give a confusing effect too, where a softer spring allows the slide to lift more, and so the needle to come out more and richen the mixture, but the softer spring will give that lift with less vacuum, so the airflow and therefore vacuum over the jet outlet is lower and so less fuel gets sucked out.

if the pilot jets are off, it'll stumble on take off. mixture screw setting may help, but the jet is more important to riding ime.

Re: DL link for wiring diagram broken up into separate systems

Saturdays Wrench said:

Link seems to be broken

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Try this direct link to google drive
https://drive.google.com/folderview?id=0B33jn0ZcimfqeWdZbXFRcWY3UEk&usp=sharing

Thanks for all the great advice everyone. I don't take anything negative. It's all a great learning experience to me.

Re: DL link for wiring diagram broken up into separate systems

Toxic Motorwerks said:

Try this direct link to google drive
https://drive.google.com/folderview?id=0B33jn0ZcimfqeWdZbXFRcWY3UEk&usp=sharing

Click to expand...

DUDE! You're the man! Thanks a lot for this

Re: "Carbonite" CB350 Cafe by first time builder

To answer your question about the plate. It can be mounted vertically but must have a light.


Knees in the breeze and mind at ease!