Mikuni Carbs for CB360

CJHusband

When in a hole, stop digging
Question for anyone brighter and more experienced than myself (everyone). I have a pair of CB360's, one early production, one later production. The later bike is complete, and ran at time of purchase. The earlier model was purchased to be a donor bike, but is in remarkable condition but lacks carbs and title.

I would like to cafe the later bike, and eventually do a resto job on the earlier one. So, the later production bike will need carbs to replace the current ones, as those will be donated to the resto bike.

I'd like some mikuni carbs, as they seem to have an abundance of jets and needles for tuning, and I plan on going with pods and a changed exhaust system. I'm thinking 30's, but I've heard 28 is ok. Any ideas as to which would be preferable?

Once carbs are selected, I have some install questions. Mikuni doesn't use a classic choke mechanism, instead using an enrichening circuit. How do people tend to connect the two carbs together, ie. operate the enrichening circuit on both simultaneously? Additionally, can some one explain the mechanics of the 2-into-1 throttle cables required?

Cheers,
Chris.
 
For mikunis, youll need a separate throttle assembly. You can modify a stock one to work, but it was designed as a push/pull assembly so it isnt ideal. The 2:1 cable is a single pull cable coming from the throttle assembly into a cylinder with a splitter inside. Two cables come out of this and into the top of each carb. The 28s are ideal for this application on a stock bore bike. They have chokes, but are separate, so you simply choke each carburetor individually when you start the bike. There are lever types and plunger (knob) types. They also had unified choke levers that came stock on some bikes and also 2:1 choke cables with a knob that could be mounted on the bars, etc.

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Yes, but the 30s are too big for a stock motor really. You can simply get carbs, and a proper cable than replace the bulky throttle/switch housing to one that works. Something from a 70s Yamaha DT is great as they ran the Mikuni carbs and its a smaller more compact unit with kill switch only.
 
So, by the sound of it, 28s are the way to go. To my knowledge the neither of the engines have been rebuilt/bored. If, in the future, re-boring is required, are 28's still going to function? or is this a situation of 28 for stock, then 30s for a re-bore?
 
If youre engine needs a rebore so large that you need to bump up carbs, I would hope it was a performance decision on your part. Worst case scenario, you would only need to go one over on the pistons/jugs and 28s would still function just fine.
 
Perfect. Thanks for the input guys, it's most appreciated. I defend my thesis mid May, expect the beginnings of a build thread a few days after. It's only fair that after I take, I give back!
 
VonYinzer said:
Yes, but the 30s are too big for a stock motor really.

The 28mm will work but I've had the VM30's on a CB350 which is stock except for Pods and Exhaust. They run mint when properly jetted and tuned. If doing any mods down the road, you can just step up the jets on the 30's.
 
VM28s are ideal, but they're more expensive as they're usually only available in flat slide versions. VM30s will work as well.
 
VM28's will support around 28~30bhp per cylinder so are plenty big enough for a modified 360
Obviously they won't have the same flow as 30's but in all probability, 90% of the time you won't need it.
Smaller carbs are much easier to tune as hey 'see' higher airflows over discharge ports
 
so im looking to get mikuni for my bike but the only thing im having a problem with is finding intake manifold for the vm28 can anyone tell me where i can order the carbs and the manifold at please?
 
30's are easier to fit, use CB350 manifolds
The 28's probably have 'small body', there are two different body sizes
Last ones I did I made adapters and shrunk them onto carb spigot
 
I can get you the carbs for less than retail, but the VM28s are significantly more expensive than the VM30s.
 
PJ, when you say to use the cb350 Carb manifolds are you talking about the rubber boots? I'm still picking up the lingo but was having trouble making a connection from term to part.

Sonreir, I came across a post a little while back about group orders. Missed it at the time. What would the timeline and price be on the vm30`s?

Chris.
 
Dime City Cycle has the Mikuni kits with throttles. They even offer some kind of "race version" with special slides that wake up the transition from mid to WOT.

I haven't got around to installing them yet but they look very complete. I upgraded the throttle to a 1/4-turn arrangement so I may look at the Scott something-or-other race setup.
 
Anyone know if these: http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-intake-parts-honda-cb-350-mikuni-rubber-carb-boot-002-053.html

Fit the Cb360?
 
I'm glad i saw this thread before I bought my Mikuni's. Definitely looking to see if the 350 boots will fit and want to see what the price drop could be for the 30s
 
I've got 30's on my 360. They fit the stock insulators just fine. If you buy the kit from DCC, you'll be pretty close on jetting. Sync the carbs (there's a how to somewhere here). I messed with them all summer, and have the needle one clip down from the top. You'll be soldering your own cable ends.

Seth
 
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