Mikuni 42mm carb manual

The throttle cable adjusters will need to be slackened to allow the cables to be disconnected from the carburetor. The Rivera dual-carb was designed to be operated with standard and later Harley-Davidson throttle cables.

Attach the Rivera dual-carb manifold using the enclosed flanges and seals. The rear cylinder flange is marked with "R" and the front with "F". Place the flanges and seals onto the manifold and loosely attach the manifold to the cylinder heads using the stock bolts.

Attach the Rivera manifold support bracket to the cylinders in the appropriate method for your type engine:. Pre '92 engines use 2ea. Center the intake manifold between the cylinder head and securely tighten the mounting hardware i. Before inserting the carburetors into the intake manifold, make certain that the choke cable is positioned pointing downward, between the carburetors and intake manifold.

Insert the carburetor spigots into the manifold spigot seals with a slight rocking motion. As the mounting nut is tightened, assure that the carburetors are sliding into the spigot seals smoothly and evenly; wiggle the carburetors by hand to help the process.

Tighten the mounting bolt until the capped carburetor fitting close to the mounting bolt contacts the intake manifold. The mounting bolt threads should bottom at the same time. I t is very important that the carburetor mounting bolt is not over-tightened to prevent damage to the seals.

Route the choke cable knob up through the triangular space in the manifold If the carburetor mounting bolt blocks the hole too much, back it out until the knob fits through then re-tighten the mounting bolt.

The nut that secures the choke bracket to the manifold is also the jam-nut for the carburetor mounting bolt. Slide the bracket onto the mounting bolt and tighten the locknut. Slide the knob into the cable bracket slot as in the illustration and tighten the jam nut. The Rivera dual-carb kit was designed to use the stock and later throttle cables.

Before attaching the throttle cables, assure that they are in good operating condition and well lubricated. Check to assure that the throttle cable adjusters are completely backed-off. Insert the end of the opening cable into the throttle wheel in the position indicated; do-not insert the cable housing into the cable bracket at this time. Insert the end of the closing cable in the remaining throttle wheel hole hold the opening cable out of the way as necessary and insert the cable housing into the cable bracket.

Insert the opening cable housing into the cable bracket. The cables overlap in the throttle wheel between the two holes but donot rub against each other during operation. Check the throttle for smooth operation. Open the throttle to the full open position and look into the bore of the carburetors to. If they are not, adjust the opening throttle cable until the throttle valves clear the bores. Route the fuel line between the cylinders, below the intake manifold.

Cut off any excess hose before attaching it to the carburetors. Secure the hose with the remaining enclosed clamp. S - As required, attach the vacuum hose for the V. Route the hose down between the engines and transmission. Cut the hose off flush with the bottom of the engine. Secure them as necessary with cable ties from the kit. Welcome to ManualMachine. We have sent a verification link to to complete your registration.

Log In Sign Up. Forgot password? Enter your email address and check your inbox. Please check your email for further instructions. Enter a new password. For tuning procedures we have a number of manuals available to the left. This is perhaps one of the best written book on carb tuning, just ignore the accelerator pump section if using a non pumper carb and remember that the mixture screw is an air screw where as on carbs with the screw located behind the bowl it will be a fuel screw in which case winding out is to make richer not leaner.

By following the procedures in the book you will determine if jets need changing and in what direction. Order required jets as your checks tell you. Please positively identify your jet type in the jets section, as all jet sales are final with no refunds. Remember the tuning order is — idle circuit , then main jet and then finally mid range. If at all in doubt, see your local tuning shop.

Then count the turns from this point to bottoming out, if you take less than 3 and more than 1 complete turns to achieve bottom, the jet is correct and you simply wind back to the centre point. Job done. If the jet is wrong, either having no stumble in one direction or the centre point being out of the range this will let you know that a jet change is required and weather you need to order richer or leaner jets.

Nothing else other than the pilot jet has an effect at idle. Some engines will actually have two size jets that may fall within the spec in which case see which feels better when riding, generally the richer one. At wide open throttle only the main jet is working so these are also very easy to tune with a few jets and a bit of spare time.

The performance changes can be detected at wide open throttle in low gears- we do not recommend the operation of motorcycles over the speed limit. Change and test with the next size jet both up or down to determine weather an improvement can be obtained and in what direction.

If you notice an improvement in one direction, keep changing to the next jet size in that direction till the improvement stops and she drops off the perch , then go back one.