Installation of dynoyet carburetor by Harley Davidson

Bring more joy to carburetor
previous page PreviousIt was mentioned that fuel or injection needs to be adjusted if there is a change in the exhaust port or air filter, or if any other change occurs that affects the volumetric performance of the engine (the amount of air entering and leaving).

CV carburetor
I'll explain how this adjustment can be made to the Keihin CV carburetor, which provided the serial equipment for all HD (and many other engines) from 1989 to 2006. It's a "constant vacuum" carburetor that works well on street motorcycles, but it's the first batch to be thrown into the trash can by many car owners who want to improve the performance of their motorcycles by replacing it with a bigger carburetor, S & S Mikuni, Rivera... On this point, I would say that in an engine as high as 88ci (1450cc), used in the "street", a larger carburetor will not always be better. The reason is that if the carburetor is too large, we will lose the low and medium speed reaction where the most engines are used. If we don't race, our butt and crane tree are less aggressive, then Keihin CV's nearly 40mm venturi is enough to make our v
Except that the air flow increases after changing the discharge or filter We must also take into account that the configuration of these vaporizers is not ideal due to the need to comply with pollution emission standards (therefore, it is the responsibility of the owners to modify the vehicles for public use). Carburetors are made of extremely poor mixtures and sealed adjusting screws, and even air filters act as noise silencers. Therefore, it is recommended to replace carburetors with high-performance K & n or similar filter elements.

Let's get to work
Let's turn the boring carburetor into a happier element Curt Dino.

I chose this kit because it is particularly suitable for motorcycles of every year and model, but it is possible to install similar kits from any other manufacturer (Yost, scratch'eagle, cycle pro, slinger...). This bag has two holes, adjustable needles, diffusers of all sizes (GUM), latex tubes, and even a glue that won't make the motorcycle run faster. It's cool in the lid of our toolbox. In the photo, I also added a low-speed jet and a new carburetor inlet.
The first thing we need to do is to remove the carburetor from the motorcycle according to the instructions in the service manual. Then we will drill the plug for sealing to enter the adjusting bolt to mix into the deceleration.

Be very careful, because we can always break the screws underneath. All we need to do is make a small hole in the plug, insert and remove the screw, and pull the plug out with pliers (we throw both the plug and the screw out). Then we cleverly stuck the adjusting bolt until it was fixed and dragged it three times, which would enable us to start the motorcycle to adjust the fuel.
We're going to remove the main transmitter and the latex tube and replace it with someone in a box We chose the diffusion coefficient recommended in the manufacturer's directive, depending on whether the motorcycle is completely original, with a high-performance filter or air leak, or a high-performance cam tree.

From the image above, we can see the screw and the radiator that has been replaced. We re installed the Cuban cover and removed the top of the carburetor, took out the spring and vacuum piston, used drill 35, rig 29 is provided in the kit, and we will start to expand the piston hole (eyes, do not confuse with the central hole of the needle). This operation, together with the replacement of a lighter terminal, will make the carburetor respond more quickly.

We reassembled everything, considering replacing the docks and needles with new ones. On the needle, we will install a needle according to the manufacturer's instructions and place it on the three pads.

When we close the lid, we have to be careful so that the board of directors can be secure Tip: before we press the screw down, we press the cover with our fingers, then climb up and put down the piston to see if there is a vacuum to slow it down.

Let's go vaporizing
Once the carburetor and filter are installed, we start the engine and bring it to operating temperature. We adjusted the deceleration (not too low) and slowly stuck the mixing adjustment bolt until the engine started to malfunction. We notice this position, slowly pull out the screw until the engine fails again, and we notice the new position, and the ideal mixing bolt adjustment is exactly half of the distance between the two positions. Tip: if the mixing screw needs to be detached from the fully closed position for more than 3.5 turns, we may have a slow speed jet that is too small for our engine to bear. I recommend a 3545 for sports and evolution, and a 3548 for Twincam 88. We're ready to readjust the speed
If you're following the right instructions now, you'll glide a stronger, faster engine in the wind

Frank Burgan

#mecanicaharley