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| - | [[:techtalk:menu|{{ :techtalk:gototechnicalmenu.jpg|}}]] | ||
| - | ====== REF: Carburetor, Intake Manifold & Exhaust ====== | ||
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| - | ====== Mikuni Aftermarket Carbs and Upgrades ====== | ||
| - | Other than exact replacement OEM carburetors, all Mikuni aftermarket carburetors and tuning components are sold "As Is" for off road / racing use only. ((http://www.mikunipower.com/VM01.htm)) \\ | ||
| - | They are not intended or approved for use on vehicles operated on public roads or in locations where applicable engine tampering and anti-pollution laws apply. \\ | ||
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| - | There are plenty of Mikuni and Keihin carburetors in the market that are not authentic. ((http://www.sudco.com/genuine_vs_fake_carburetors.html)) \\ | ||
| - | They're not safe to use and will cause many problems to your bike. \\ | ||
| - | If you're not sure if it's a genuine carburetor, the Sudco International site has a web page with pics of genuine and fake carbs. \\ | ||
| - | Follow [[http://www.sudco.com/genuine_vs_fake_carburetors.html|this link]] or you can call them directly to verify a seller. ((Sudco International Corp. 2410 S. Sequoia Drive Compton, CA 90220 Tel.(310) 637-8330 • Fax (310) 637-8331)) \\ | ||
| - | Also, below the series models below are notes from Sudco on fake vs genuine carbs. \\ | ||
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| - | ===== HSR Series ===== | ||
| - | \\ | ||
| - | ===== Sub Documents ===== | ||
| - | * [[techtalk:ref:carb02a|Choke Relocation on a Mikuni HSR]] | ||
| - | * [[techtalk:ref:carb02e|Rebuilding a Mikuni HSR42]] | ||
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| - | {{:techtalk:ref:carb:mikunihsr424548_by_aswracing.jpg?direct&300|}} ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1594074)) \\ | ||
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| - | **Notes from Hammer Performance**: \\ | ||
| - | In our experience, we've found the CV40 to really start becoming a restriction at about 90 horsepower. ((http://www.hammerperf.com/xlfuelsystems.shtml#mikunis)) \\ | ||
| - | And they tend to put a cap on the power. \\ | ||
| - | By comparison, a Mikuni HSR42 will easily support 110hp, an HSR45 will easily support 130hp, and we've made over 150hp using an HSR48. \\ | ||
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| - | A properly jetted Mikuni HSR carburetor also delivers excellent fuel mileage. The HSR carbs are generally tuned pretty darn close right out of the box. ((http://www.hammerperf.com/xlfuelsystems.shtml#mikunis)) \\ | ||
| - | But there are a lot of adjustments if you want to tweak on it. \\ | ||
| - | One good thing about tuning a Mikuni is that the main jet can be accessed and changed without removing the float bowl. This saves time when dyno tuning a bike. \\ | ||
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| - | Many fans of the CV carburetors talk of it's altitude compensating capabilities. In our opinion, this is overrated. ((http://www.hammerperf.com/xlfuelsystems.shtml#mikunis)) \\ | ||
| - | We've taken both Mikuni and CV40 carburetors to the top of Mt Evans in Colorado, for example, which is over 14,000 feet. \\ | ||
| - | Both ran equally poorly, but both ran. We don't see any real or measurable advantage in the CV in the way of altitude compensation. \\ | ||
| - | The altitude compensation method of the CV, which is to put the bowl vent into the intake stream, also causes all kinds of issues with certain air cleaners that don't provide the proper aerodynamics for it. \\ | ||
| - | So it can be troublesome to tune depending on the specific combination. We never have such difficulties tuning Mikuni carburetors. \\ | ||
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| - | Notes on Mikuni Carburetors: ((http://www.hammerperf.com/xlfuelsystems.shtml#mikunis)) | ||
| - | * The HSR42 will fit and work fine in a stock CV40 intake manifold. The HSR45 or HSR48 require a larger intake manifold. | ||
| - | * The latest HSR series carbs are designed to work with stock big twin throttle cables. \\ When put on a Sportster or Buell, it is sometimes necessary to bend the cable bracket back a little bit to achieve proper throttle cable adjustment. \\ | ||
| - | * The HSR42 requires the re-use of your stock choke cable. A new choke cable is included with the HSR45 and HSR48. | ||
| - | * The HSR48 comes with a rubber boot to adapt it to a two-bolt style manifold. \\ | ||
| - | * This works but places the carb farther out than stock. To mount the HSR48 in the stock location, use the large carb slip-fit manifold. \\ | ||
| - | * To use a CV type air cleaner with these carbs, you need a CV air cleaner adapter. | ||
| - | |||
| - | **Fake vs Genuine Mikuni HSR**: \\ | ||
| - | The top cover has a different design compared to the genuine. \\ | ||
| - | Also you can locate the size of the carburetor and the "Mikuni" logo on the genuine while the fake carburetor doesn't show it at all. \\ | ||
| - | The fake carb is also missing the "Assembled in Mexico" decal. \\ | ||
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| - | ===== VM Series ===== | ||
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| - | ===== Sub Documents ===== | ||
| - | * [[techtalk:ref:carb02j|Function and Tuning of a Mikuni VM-38-9]] | ||
| - | * [[techtalk:ref:carb02k|Mounting a Mikuni VM-38]] | ||
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| - | These are early VM series round slide Mikunis - 34, 36, or 38 MM \\ | ||
| - | Only Mikuni round slide carbs are designated as VM. These are available in different sizes such as VM29, VM34, VM38, VM40 etc. ((piniongear of the XLFORUM http://xlforum.net/forums/showthread.php?t=1675923&page=2)) \\ | ||
| - | HS and HSR carbs are not round slide. The RS is not a round slide. The TM and TMS/TMX are not a round slide. \\ | ||
| - | This is a very old school set up for a Sportster. Properly set up, this carb gets good mileage and runs well. ((nemosengineer@yahoo.com of the XLFORUM http://xlforum.net/forums/showthread.php?t=266722)) \\ | ||
| - | **Note Safety Tip**: Cut a piece of bicycle inner tube to stretch over the carb-body and slide-cap to stop the cap from un-screwing. \\ | ||
| - | This will keep the slide and needle inside the carb on the freeway. \\ | ||
| - | You can call Sudco to see what they recommend for jetting after you identify which model Mikuni VM you have. \\ | ||
| - | Sudco will get you close. You can also get a little tool kit they sell with the jet wrench's and don't forget the Mikuni pocket tuner. \\ | ||
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| - | Mikuni lists the following Vintage Carb Kits: ((piniongear of the XLFORUM http://xlforum.net/forums/showthread.php?t=765846&page=8)) \\ | ||
| - | 001-200....HDS-101/38mm.... Sportster/Shovelhead \\ | ||
| - | 001-204....HDS-101A/40mm.... Sportster/Shovelhead \\ | ||
| - | 001-202....HDS-101B/44mm.... Sportster/Shovelhead \\ | ||
| - | So any of these 3 sizes will work. | ||
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| - | **Considerations When Buying**: \\ | ||
| - | The Mikuni will stick out a bit further than other carbs, mainly because of the adapter. \\ | ||
| - | On a Sportster, you need to buy a throttle cable with the carb that has a 90° elbow fitting into the carb top. \\ | ||
| - | This is needed to be able to run the throttle cable under the gas tank. \\ | ||
| - | A new manifold is required along with a carb adapter or rubber boot and air cleaner mount. \\ | ||
| - | Several ways are described in the mounting article above. \\ | ||
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| - | The correct version of the VM38 for an ironhead Sportster is the VM38-9. ((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1814834&page=2)) ((piniongear of the XLFORUM http://xlforum.net/forums/showthread.php?t=765846&page=3)) ((piniongear of the XLFORUM http://xlforum.net/forums/showthread.php?t=765846&page=4)) \\ | ||
| - | The VM38-"9" was setup and extensively tested by Jerry Branch for the stock Sportster engine using flow bench tech for the time. ((simeli of the XLFORUM http://xlforum.net/forums/showthread.php?t=1636803&page=2)) \\ | ||
| - | It is going to be hard to find that you are going to be able to improve on it as supplied. Unless you are running a stroker or highly modified heads and cams. \\ | ||
| - | Then the as supplied needles and jets are going to be your best option. Clean it out and replace with the normal "9" needles and jets. \\ | ||
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| - | There were a bunch of different VM's (round slide) from 16MM on up to 44MM with the vast majority of them designed for 2 cycle engines. \\ | ||
| - | The VM-38 Standard Right body may be the same for all of the 38MM units. \\ | ||
| - | However, all the particulars have to be correct for the VM38-9. Below is the list of all the things that make it a "9". ((simeli of the XLFORUM http://xlforum.net/forums/showthread.php?t=1675923)) \\ | ||
| - | * Bore Size : 38mm | ||
| - | * Spigot Mount : 43mm | ||
| - | * Main Jet : 4/042 #330 | ||
| - | * Pilot Jet : VM22/210 #30 | ||
| - | * Needle Jet : #166 Q-2 | ||
| - | * Throttle Valve : VM38/24 2.5 | ||
| - | * Jet Needle : 6DP1 (the clip is set in the middle notch. That is the third notch from the top or bottom.) | ||
| - | * Needle Valve VM34/39 3.3 | ||
| - | * Air Jet : 2.0 for Sportster (002-165) \\ 0.5 (BS30/97) for BTs but reportedly works fine on a Sportster. \\ Sudco's website shows a 0.5 for the VM38-9 but the VM-38 manual says the 2.0 | ||
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| - | This particular model is a VM-38mm. It has no numbers on it other than "Mikuni KOGYO". \\ | ||
| - | {{:techtalk:ref:carb:38mm_mikuni_vm_pic_1_by_sturgmachinist.jpg?direct&300|}} ((photo by sturgmachinist of the XLFORUM http://xlforum.net/forums/showpost.php?p=1361935&postcount=1)) {{:techtalk:ref:carb:38mm_mikuni_vm_pic_2_by_sturgmachinist.jpg?direct&300|}} ((photo by sturgmachinist of the XLFORUM http://xlforum.net/forums/showpost.php?p=1361935&postcount=1)) \\ | ||
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| - | Here is another VM-38. \\ | ||
| - | {{:techtalk:ref:carb:vm-38_pic_1_by_donw.jpg?direct&300|}} ((photo by DonW of the XLFORUM http://xlforum.net/forums/showpost.php?p=3984744&postcount=1)) {{:techtalk:ref:carb:vm-38_pic_2_by_donw.jpg?direct&300|}} ((photo by DonW of the XLFORUM http://xlforum.net/forums/showpost.php?p=3984744&postcount=1)) \\ | ||
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| - | Mikuni VM-38 with solid mount adapter to run on a shovelhead. \\ | ||
| - | The adapter is a tight press fit with three set screws. There are threads in the adapter to run the bolts into. \\ | ||
| - | And there is a groove /O-ring inside the aluminum adapter bore. \\ | ||
| - | {{:techtalk:ref:carb:vm-38_pic_1_by_claysbury.jpg?direct&300|}} ((photo by claysbury of the XLFORUM http://xlforum.net/forums/showthread.php?t=1814834)) {{:techtalk:ref:carb:vm-38_pic_2_by_claysbury.jpg?direct&300|}} ((photo by claysbury of the XLFORUM http://xlforum.net/forums/showthread.php?t=1814834)) {{:techtalk:ref:carb:vm-38_pic_3_by_claysbury.jpg?direct&300|}} ((photo by claysbury of the XLFORUM http://xlforum.net/forums/showthread.php?t=1814834)) \\ | ||
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| - | This one is stamped "X66" with the X above the 66 and one of the 6's is sideways. It also has 38F 9 on the back side just below the choke\enricher. \\ | ||
| - | {{:techtalk:ref:carb:vm-38_pic_1_by_asasial.jpg?direct&300|}} ((photo by asasial of the XLFORUM http://xlforum.net/forums/showthread.php?t=1151844)) {{:techtalk:ref:carb:vm-38_pic_2_by_asasial.jpg?direct&300|}} ((photo by asasial of the XLFORUM http://xlforum.net/forums/showthread.php?t=1151844)) \\ | ||
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| - | {{:techtalk:ref:carb:vm-38_pic_3_by_asasial.jpg?direct&300|}} ((photo by asasial of the XLFORUM http://xlforum.net/forums/showthread.php?t=1151844)) {{:techtalk:ref:carb:vm-38_pic_4_by_asasial.jpg?direct&300|}} ((photo by asasial of the XLFORUM http://xlforum.net/forums/showthread.php?t=1151844)) {{:techtalk:ref:carb:vm-38_pic_5_by_asasial.jpg?direct&300|}} ((photo by asasial of the XLFORUM http://xlforum.net/forums/showthread.php?t=1151844)) \\ | ||
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| - | **Fake vs Genuine Mikuni VM**: \\ | ||
| - | The fake VM carburetor has the "Minkui" imprinted on the top and side of the carburetor. \\ | ||
| - | On a genuine carburetor you will find the "Mikuni" logo. \\ | ||
| - | Also you will notice that the fake carburetor doesn't have the "NOT FOR AIRCRAFT USE" decal and the anchor plates. \\ | ||
| - | The way the fake carburetor was designed is completely different from the genuine one. There are extra openings and attachments. \\ | ||
| - | Also see this [[http://www.sudco.com/genuine_vs_fake_carburetors.html|Sudco International]] web page for pics of fake vs genuine VM carburetors. \\ | ||
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| - | ===== HS-40 ===== | ||
| - | The HS40 is a Flat slide Mikuni Carb. \\ | ||
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| - | The stamping on mouth of this one reads "T40 6W" . \\ | ||
| - | The jets included in it are in the pic to the right. \\ | ||
| - | {{:techtalk:ref:carb:mikuni_hs-40_carb_by_batousaii.jpg?direct&250|}} ((photo by Batousaii of the XLFORUM http://xlforum.net/forums/showthread.php?t=1632427)) {{:techtalk:ref:carb:mikuni_hs-40_jets_by_batousaii.jpg?direct&250|}} ((photo by Batousaii of the XLFORUM http://xlforum.net/forums/showthread.php?t=1632427)) \\ | ||
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| - | ====== Helpful Links ====== | ||
| - | |||
| - | * [[http://www.mikunipower.com/HSR01.htm|Mikuni website (HSR page)]] | ||
| - | * [[http://www.mikuni.com/fs-carburetor.html|HSR Installation Guide]] | ||
| - | * [[http://www.mikuni.com/fs-performance_guide.html|Performance Guide]] includes: | ||
| - | * Air Cleaner Basics, Exhaust System Basics, Cam Basics and Ignition Basics | ||
| - | |||
| - | * [[http://www.mikunipower.com/Manuals/HSR_SportsterBuellInstallation.pdf|Sportster / Buell Installation Instructions PDF]] | ||
| - | * [[http://www.mikunipower.com/Manuals/HSR42-48_Manual.pdf|HSR42/45/48 Tuning Manual PDF]] | ||
| - | * [[http://www.mikuni.com/pdf/how_to_choke_cable.pdf|HSR Choke Cable Installation Tips]] | ||
| - | |||
| - | * [[http://www.mikunipower.com/Manuals/HS40_Manual.pdf|HS40 Tuning Manual & Parts List PDF]] | ||
| - | * [[http://www.mikunipower.com/Manuals/HS40_Manual.pdf|HS40 Tuning Manual PDF]] | ||
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| - | * [[http://www.mikunipower.com/VM01.htm|Mikuni website (VM page)]] | ||
| - | * [[http://www.mikunipower.com/Manuals/VM_Manual.pdf|VM "Round Slide" Tuning Manual]] | ||
| - | * [[http://www.mikunipower.com/Manuals/VM26_Rebuild_Kit.pdf| Rebuild Kit VM26-606 PDF]] | ||
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| - | * [[http://www.mikunipower.com/Manuals/HSR_PATInstallation.pdf| PAT Upgrade Kit Installation Instructions PDF]] | ||
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| - | * [[https://www.jetsrus.com/a_jets_by_carburetor_type/jets_mikuni_HSR_series.htm|Genuine Mikuni jets for HSR series carbs]] | ||
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| - | Video: \\ | ||
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| - | * [[https://www.youtube.com/watch?v=xm-UVTPjRbo|IronMick's VM-38 Startup Video]] | ||
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