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Discussion Starter #1
I took my carbies apart and after inspecting them, there two far gone to rebuild ( both chrome covers have holes in them - Rust, five bowl screws snapped off after striping the heads with an impact driver, and both mixture screws refuse to move)

I've now decided install Mikuni carbs. The info I've managed find is the VM30's for round performance and VM32's for high performance engines. I have no plans of going beyond carb, ignition and exhaust mods . I'd like to know from anyone who's installed them and if your bike (mine's a '72 SL350 K2 with a '71 CB350 engine) any good with Mikuni's fitted . getting them isn't a problem as I get a kit from Mikuni Oz, the Australian importer and once I don't have to deal with all the
import carp I deal with.
 

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Hi Moondoggy,

My only experience with Mikuni carbs is with my '76 XL350. I did a lot of research on what experiences other XL owners had with their Mikuni conversions. The result was that there was a wide variety of specifications (jetting, needles, slides) based on how they ran their bikes, modifications and their expectations.
It took me about a year to get my machine tuned to where it ran as I expected it to for basic pleasure riding on and off road. I kept records of how it performed when jets, slides, needle and needle position were changed. Also changes to the SuperTrapp muffler; It finally ran as I expected when the stock exhaust was reinstalled.

As to your original question "How good are Mikuni's". Its not that they are better than the 48 yr old stock carbs (in usuable condition with all systems on the machine up to specs) but that they are available and tuning parts are readily available for them and the experience of others is available to possibly help you dial them in.

One bit of advise I did glean from all my carb research was "make sure your electrical and ignition system is 100% because many carb problems are caused by problems there and not with the carbs.

Good luck chasing the carb demons!!

Mark
 

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Discussion Starter #3
thanks for that . About the good luck I've had lately is unseizing the engine so far .All I did was put my 160 KG body on the Kickstarter and the engine freed up . I looked at the ignition , the points look perfect after static timing it and the coils tested OK and all the electrical connections are good .
 

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Be prepared to spend A LOT of time and money (in jets) to tuning the Mikunis if you decide to use them.
They're not better or worse than the stock carbs just more "customizable" if you will.

Personally I would never use them.
 

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It took me about a year to get my machine tuned to where it ran as I expected it to for basic pleasure riding on and off road.


That says it all I think.
 

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Discussion Starter #6
In my case I don't have much of a choice . Both diaphragms are ruptured , the diaphragm tops were so rusty I blew 5 holes in them sandblasting at 20PSI (the idea was to get them ready for chroming) , there are bowl screws snapped off in both housings and if I didn't know any better , inside both the bowls look like they've salt water instead of fuel running thru them . I had a go at importing a set of Klein's for a CB350 K3 from a Californian wrecking yard ( I live at Hay Point , Queensland , Australia ) , It cost me $700 only to the carbs have go missing somewhere .
 

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On this page in the SUDCO Catalog they show a pre-jetted 1968-72 Honda CB/CL 350 Mikuni VM carb kit that is available from a Sudco dealer. Maybe there is a dealer in your part of the world so that you can save shipping!

The catalog also shows other brands of carbs and tuning parts. The catalog has over 600 pages. I only just discovered this general motorcycle catalog while looking for this link; I have their Mikuni Tuning Manual that is really just a carb and jetting/tuning parts catalog with tuning information. I'm going back to the site and download a copy for my information file.

Bad luck about your California carb order going missing.

Mark
 

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Discussion Starter #8
Thanks for that nebraska , I'll look into that catalog . There's a company in Townsville (around 250/300 KLM's north of where I live ) called Mikuni Oz . Apparently he's the Australian distributer of Mikuni carbies and sells quite of carb kits to your American retailers . He does one for SL//CL/CB350's ( and I think it the 450's as well ) that includes the carbs , air filters , throttle cable and his own intake manifolds . And at least I don't worry parts going missing .
 

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It took me about a year to get my machine tuned to where it ran as I expected it to for basic pleasure riding on and off road . . .
Am staring down the barrels of this process right now with a 450 K5. Probably put posts up about it somewhere else but long story short, I bought a 'pre-jetted' set of VM32's and while yes, they came with jets, the jetting I seem to need on my stock bike is outside of the range of bits that came in the kit. Way too rich at idle and coughing up at open throttle/high RPMs. Bought myself an idle jet kit and a main jet kit with eight or so different size jets in each and will be going backwards and forwards with plug chops.

As the others have said, the Mikuni's aren't better or worse, they're just different but with a better parts supply.
 

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Discussion Starter #10
For me , tuning Mikuni's isn't problem . It's usually getting the parts to tune them . I've been racing 2 and 4 stroke dirt bikes since I was ten . In my part of the planet , it's the Klein's that are hard to get parts for .
 
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