This is a re-print of a write-up I did a while back on RIMC. It is archived here to avoid being purged in the future.
Today I had the time and parts to re-jet the Keihins on the Raven. She had been kinda lugging on acceleration and while starting, the right side cylinder wanted to burp, fart, and sputter for a few minutes until it got warm.
Here's the parts you'll need:
- New CVK main jets - I went with 130's (the stock carbs come with 125's)
- New CVK pilot jets - I went with 45's (the stock carbs come with 38's)
- 3/16" and 1/8" flat blade screwdrivers (if you have them about 12" long it works better)
- Phillips screwdriver
- 3mm Allen (hex) wrench
- pan to catch a small amount of gasoline
- dish to hold carb screws (I have one of them little magnetic parts dishes which is handy)
You can get the jets from a variety of sources: Sudco (http://www.sudco.com
), carbparts.com or perhaps your local Kawasaki dealer. I think they use the same Kehin carbs as the Urals on the Kawasaki Concours. I bought mine form Holopaw Gene - http://www.uralfla.com
Before undertaking this project, I had studied Dwight Rahl's CVK carb re-jet website and it was extremely helpful! Link: http://www.dwightrahl.com/carb-jetting.html
Dwight removed the carbs from the heads to re-jet them. There's nothing wrong with doing it that way, but there's more than one way to skin a cat.
I didn't want to go thru the hassle of removing and remounting the carbs, so I chose to do it with the carbs still fastened to the bike. It's a little bit trickier, you have to lay on the garage floor while doing it. If you have a 2WD, it makes it a little easier to shimmy under the sidecar to do the right side carb. If ya gotta 1WD model, you might need to jack up the sidecar a bit. The shift lever and the rear brake lever might be in the way slightly but I was able to work around them.
Step 1. If you have a vacuum operated petcock, remove the vacuum line from the left side carb that goes to the fuel tank petcock valve.
Step 2: Put a catch pan under the left side carb and disconnect the fuel line from the carb. This will drain all of the gas out of the fuel lines and filters.
Step 3: use a 3mm Allen wrench to open the drain screw on the right side of the bottom of the float bowl. Once the gas has completely drained, tighten it back up snugly so you don't forget to do it later.
Step 4: Use a Phillips screwdriver to remove the 4 screws underneath the carb that hold the float bowl to the carb body. I find that you need a fat Phillips screwdriver with a sharp point, so as not to booger up the screw heads (they booger easily). As you remove the screws put them in your dish so you don't lose them. One day I should prolly swap out those Phillips-head screws for some nice little Allen head bolts.
Once you have the float bowl removed, take a look, there are three jets inside: The main jet, the pilot jet, and the starter jet. I attached a pic showing where they all are located.
I replaced the main jet and the pilot jet on both carbs. The starter jet is for the enrichener (choke) circuit and is only used when the enrichener know is pulled. I left that one alone.
The main jet is right in the middle, and the pilot jet is recessed in a cavity near the other two jets.
Step 5: using the 3/16" flat blade screwdriver, remove the existing main jet and install the new one. The main jets have numbers stamped into the side of them. My existing ones were 125 and I switched them to 130.
Step 6: Using the 1/8" flat blade screwdriver, remove the existing pilot jet and install the new one. You'll have to shimmy under the bike so you can see the slot so you can position the screwdriver. Test you screwdriver with one of the new jets first to make sure it fits. You don't want to booger up the the slot. The pilot jets are stamped with a number in the bottom face. My existing ones were 38's, I switched them to 45's
Step 7: Look at the float bowl, clean any crud outta there. I found just a little crud in there. Put the float bowl back on the carb and tighten the four Phillips head screws.
Step 8: Repeat Steps #4 through #7 for right side carb.
Step 9: Reconnect the vacuum line to the petcock and the fuel line on the left side carb
Step 10: If you have a vacuum operated petcock, turn the lever to the "PRI" (prime) position for about 30 seconds to fill the carbs with gas then place it in the "ON" position.
Step 11: Start the bike!
I found that the bike was easier to start. It still sputtered just a little on the right side for the first 15 seconds, but nowhere near as bad as before. I took it for a little spin around the block a few times. She accelerates easier and is more responsive while coming off idle.
The whole process took about 25 minutes. I hope this helps.
Here's a few pictures
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