New carbs?

[moonie527]

So after the carb clean and rebuild my '73 cb350 twin still runs terrible. Some of the carb internals are pretty beat up and I'm wondering at what point to cut my losses and
1. find a good pair of used carbs.
2. pay for a pro to handle mine or another pair.
3. buy the Mikuni setup.
4. sell the bike and stick to wrenching on vehicles of the 4 wheel variety.
I'm a little impatient so the Mikunis are the quickest route to take. Anyone have experience with them? Such as were they good out of the box or did they have to be dialed in. Any performance gains/losses with them? I'm also a cheapskate so any other suggestions cheaper than the Mikunis would be appreciated.

 

[rudy]

I'm a little impatient so the Mikunis are the quickest route to take. Anyone have experience with them? Such as were they good out of the box or did they have to be dialed in.

Any carbs should be dialed in when you put them back on the engine. Unless you're not dismantling them at all, they should be tuned. You'll have to set your mixture screws and sync throttles between each carb as well. As far as jets, stock should be fine if you still have the stock (or close to it) airboxes and exhaust. The best tool for setting the mixture is a colortune spark plug. Google it if you don't know what it is. It's pretty easy to understand. There's a few different ways to set the sync. Some use a manometer, which is said to be one of the better ways to do it. Others use vacuum gauges. Either your carb holder boots will have vacuum gauge spigots, or there will be somewhere on your carb bodies to hook one up.

If you've taken the engine apart, you should check ignition timing as well.

I've heard Keihin carbs are a little tricky, and people like the Mikuni ones better. I haven't had any experience with the Keihin's yet, but I've played with a few different Mikuni's. Keep asking around and you'll find someone that's done the conversion.

 

[liam]

i'm interested in the original questions as well, been hunting for some definitive answers,
but also, i've got a friend with a dr800 (single cylinder twin carb motardy streetfighter) which runs twin mikuni BST33's. he's most likely upgrading to a larger pair,
are these suitable for a cb350?
the bikes they come stock on are much larger capacity, but it's only one mm larger then the VM32's, and for a low price, i imagine they're racked together somehow, so i need to have a look at them.
i have no idea about flow characteristics or anything, so it may be a totally stupid question...