Let's start out by giving a shout out to the guys and gals on the 650 "CC&D" site and forum.  I've personally been a member over there since 2001-2002, and have always found that site and forum very useful.

Ok, guys and gals... the single carb conversion kit is from KJS http://kjsmotorcycleworks.com/.  KJS ships out of Ontario Canada, so it takes a few days for delivery here in the US. The kit arrived in my local area when promised. However, it took me a couple of days to get it from the post office. The US Postal Service would not drop it off at the door for me when I was at work, so I ended up taking off work early one day to get over there.

Here is the bike I am working on.

As you can see, I have it on my bike lift and it is strapped down. I highly recommend using the bike lift for all your maintenance and modifications.

Visual Inspection

The KJS parts were packaged in plastic and newspaper when I received them.  The carb and mounting boot were in plastic, and the manifold was surrounded by newspaper.  Attached to the manifold with tape was the four bolts to attach the manifold to the jugs.  Also attached loosely to the manifold was the gaskets for the jugs and the washers and mounting bolts for the carb.

The manifold looks really good.  It is a clean aluminum casting and the finish is good.  I couldn't wait, so I stuck it between the jugs to see how it'll fit... drops right in there.

The 40mm Mikuni carb is nice. Ken at KJS made sure that the carb parts were labeled and good to go.  As previously mentioned, the carb and boot came in plastic.

As you can see, Ken made sure to label everything.  I will say, I am very mechanical, so this was probably not required, but nice that he is so detailed as to help out the home mechanic.

Ok, now let's get into it.

Required Tools

So, I will start by listing some of the tools and supplies needed to get going:

• Digital Ohm Meter
• 3x 18inches of multi strand wire 18guage (used to extend the TPS harness)
• Solder
• Solder Gun
• Heat shrink
• Heat Gun (no, I don't use a lighter, lol... I am a firm believer in using the right tool for the job)
• Phillips screwdriver
• Straight Screwdriver
• Razor Blade Knife
• 10mm wrench
• 10mm socket & wrench
• 12mm socket
• 6 inch socket extension
• Full Set of Metric Allen Wrenches
• Small needle nose style vice grips (This is used to remove the TPS from old carb setup.  The TPS is held on using two screws that have that star shaped with the dot in the middle safety thing-a-ma-giggy, just use the vice grips)
• 2 foot 5/16 fuel line
• breather filter element for the crankcase
• Black RTV Silicone Gasket Maker

Note!

KJS does have an installation video on their website, but it is not for a 650 VStar. Now, it is useful to look it over and see the order of tightening down the manifold to the jugs. The manifold itself drops onto the flanges on the jugs much like a Harley... quick and simple!

Disassemble Your Ride (sort Of)

Remove the speedometer & housing on the top of the tank by removing the three aluminum allen bolts, gently pull up on the housing, reach under and disconnect the speedometer cable and disconnect the electrical connections under the housing.

Remove the tank bolts back by the seat.

Remove the fuel line at the gas petcock, make sure that the petcock is set to off first.

Remove the tank and set aside.

Now, you can remove the air box, carburetors, and the rubber intake manifold boots.

The AIS can be removed if you haven't already done this modification... mine has been gone for nearly 10 years

Keep the dual carbs handy for later.  We will need to pull the TPS off this setup after a few.

Now, if you are unsure how to do anything I mentioned, a Yamaha service manual or a Clymers manual can be a valuable guide. 

NOTE: There is a lower air filter bracket with 2 bolts attaching it to the front jug.  You can completely remove this bracket.

HINT: Now would be an excellent time to check your valves!!!

I did not take pictures of the dissassembled bike.

Installation of Manifold and CrankCase Breather

Take a minute to clean where the jugs and the rubber intake manifolds attached.  I just used a lint free rag and some carb cleaner.

Now, take the supplied gaskets and determine how they fit best, apply a generous amount of silicone on the gasket on the side that touches the jug. Only apply the silicone around the circle part of the gasket, then stick it to the head. Gently pad down the gasket, then wipe off the excess. Do both jugs.

Now, apply silicone to the manifold where it will meet the heads. Once again, apply the silicone in a circle about 3/16 of an inch wide, and 1/8th of an inch high, be careful not to wiggle it, and install it onto the jugs with 4 bolts and washers.

When installing the manifold to the jugs, make sure to finger tighten only in a figure 8 pattern, while positioning the manifold. The mainfold matches up very well, so there should be no problems. I just snugged it up using a 10mm box end wrench while following the figure 8 pattern. Clean up any excess gasket material and let it cure some more.

Once it has cured, we can go ahead and install the rubber boot for mounting the carb to the intake manifold.

Go ahead and apply silicone to the rubber boot then install to the manifold using 2 bolts and 2 washers. 

NOTE: KJS directions state to leave a lip on the bottom inside when bolting up, so condensate fuel, doesn’t run out when parked.

Now, if you recall, the crankcase has a breather that used to attach to the airbox on top of the carbs.  I installed a small valve cover style filter at the end of this hose.  I cheated and used a vaccuum coupler and cut it up to work with the hose and the filter.  I used the stock wire clamp and a hose clamp to attach the hose and filter to the coupler as illustrated below.

Throttle Position Sensor Install

Now, we can install the TPS onto the new carb.

When removing the TPS from the dual carbs, they have two tamper proof screw’s.  The screws have that star shaped with the dot in the middle safety thing-a-ma-giggy, so unless you have those bits, just use the vise grips. All you’ll need is just the TPS switch itself, as there are new nuts, bolts, and washers supplied on the bracket on the carb.

The TPS is internally spring loaded and by turning it on the pivot shaft line it up with the two holes in the bracket with the wire plug end facing in the 6 o clock position. Bolt the TPS onto the bracket firmly, but not tight yet.

Now, go to the bike and strip off the electrical tape on the TPS harness.  If you haven't done so already, remove the harness for the carb warmers and toss it.  Strip the tape back 3-4 inches, then using wire cutters, cut all three wires (blue, yellow, black) at about the half way mark.

Take the plug and wires you just cut off and strip the wires back 1/4 inch.  Now we are ready to adjust the TPS settings on the new carb.

From the installation directions: Use a DIGATAL OHM meter set at 20K scale. Place the red led on the blue pin, black led on the yellow pin, be sure the throttle is in the closed position. Set the TPS so it reads between 0.70 – 0.76K Ohms. Turn the throttle full open, it should read between 4.01-4.15K Ohms.

Ok, I had nothing but issues with the TPS... I called KJS and was told that the directions were right on the money... it seems that you should be checking the yellow and the black pin out... my Clymer said it, and so did the following image someone posted on the 650 CC&D forum.

The TPS mounting allows you to make adjustments by rotating the sensor forward and backward on the bracket.  Once you are within range both open and closed, tighten the sensor to the bracket and recheck your settings.

I set my closed position to 0.75K Ohms, and when opened on the throttle, I only got 3.91K Ohms... hmmm ok, close enough.  Just as a side note, When I checked the TPS as described below, my numbers were right on.

Now, remove the plug from the TPS and set it aside for a while.

NOTE: The following two images show the TPS mounted in the wrong direction... flip that puppy over and set it with the prong end pointed down.  Otherwise, the TPS harness will be riding on the underbelly of your tank.

I ended up flipping the TPS around cause otherwise it
will hit the tank... the plug HAS TO BE on the bottom

Please notice in this picture the position of the TPS

Carb Installation

I jumped ahead earlier in the process and siliconed the rubber boot to the manifold.  This gave me some time for the silicon to set and cure a bit before installing the carb.  Take some WD40 and spray it on the backside flange of the carb.

Insert the carb into the rubber intake boot and rotate it till it slides in and seats. Tighten it down with the supplied clamp.

From the installation directions: There is a vacuum port rubber plug on the side if needed. There are 2 slide body vent hose’s, never block them, and one float bowl over flow hose, the 3 can be placed along the back side facing towards the rear of the engine (where the serial # plate is) and cut off neatly then the heat from the engine will make them conform to shape of the engine galley towards the left rear side of the bike in case they ever have to over flow away from the exhaust. Again, make sure there not obstructed or blocked off, TRY NOT use twist tie’s, this will cause the carb not to function, every thing as been pre adjusted, and ready to go, again, important check for vacuum leak on the manifold, DON’T even try to adjust the carb, re-install the manifold.

Throttle cables: I have beach bars and extended cables on my bike.  However, I still need to reroute my cables so that there will be no binding when I turn.  I may end up buying a longer pull cable and route it differently later on, but for now, the method in the install directions will work.

From the installation directions: Depending on what bars your using, the throttle cable will have to be re-routed to give enough slack, so when turning the handlebars, it won’t pull the gas on by mistake, and rev up the engine & reroute them on the outside of the forks and triple trees so the hang free and slip them through the right side plastic tank extension just above the ignition key. The pull cable the one with the adjusting coupler on the twist grip spin back the big nut up the metal shaft and place it in the cable holder on the bottom hole of the carb and spin the retaining nut on and place the ball of the cable in the 3rd hole will be marked as such and adjust to get the desired pull tension and slack. Then place the return cable in the top carb holder and place the ball in the 4th hole also be sure the cable and handle bar twist grip is greased and oiled for smooth operation.

Here you can see how I routed my cables .

Now, we move onto the choke.  Remove the old cable from the mount, the rebend it in the opposite direction to fit the right side of the tank.  I went ahead and loosely installed the boot to keep the cable out of my way.  Make sure to bend it enough that you can get a short socket in there.  I ended up rebending this puppy twice.

And that's as far as I got so far.

Re-wiring the TPS Switch Harness

Time to break out the solder iron, shrink wrap, and heat gun.  Make sure to tin the wires on the bike and on the plug.  Cut yourself three 18 inch sections of 18 gauge wire, and strip both ends.  Tin all six ends.  Cut yourself 6 pieces of heat shrink.  Solder the plug harness and the three wires together, slip 2 pieces of heat shrink down each wire.  Now, go to the bike and solder the new harness into the old, making sure to match the colors.  When this is done, use your heat gun to shrink the shrink wrap.  At this point, I ran electrical tape back over the entire harness to clean it up.  Then hook it up and you are good to go.

Fuel Lines

From the installation directions: You will need a new fuel line 24 inches long by 5/16 hose and two small hose clamps to fit the carb and the fuel pump outlet and route the line through the frame. With the fuel tap turned on the Electric fuel pump has to be primed turn the ignition on and off a few times until you do not hear any more click, click, click (the sound of the fuel pump pressurizing the system). There is a built in filter just off the fuel petcock line going to the pump from the factory

My Thoughts and Opinions

This has been a easy install.  I did not had a lot of time, so I apoligize that it took so long. 

I was also cleaning parts as I went, so in reality, I purposely took twice as long to get this done so that my bike is clean again.

Besides waiting for the silicone gasket to cure, I could probably do this install in under 3 hours, as long as I wasn't being anal about cleaning parts.

I checked the manifold for leaks with ether, and did not find any leaks... road test!!!

How Does She Handle

Wednesday 18 August 2010 - I don't know yet... I guess I'll let you know tomorrow night.  It was 11:00PM when I finished up this evening.  I did not get home until 7:15PM, had to cook, eat, and feed the dog and cat.  By the time I stepped out there this evening, it was 9PM.

I can say that she started up good and sounds great.  I know, its the Hard Krome Big Straights.  I don't know about that, it sounds a lot throatier.  Well, I'm done for the night.  I am pooped.  I'll update this entry tomorrow evening or Friday and let you know how big my grin really is.

Thursday 19 August 2010 - Ok... 1 1/2 hour test run... lol.  She handles like a dream.  The throttle response is amazing, it is a tight throttle, but the bike definitely has more torque.  For example, I was traveling 80 mph on the highway in 5th gear, I decided to pass the vehicle in front of me.  I barely moved the throttle and I was doing 95 and climbing.

The bike absolutely hates being in 5th gear if under 50 miles per hour, but it is indeed handling great.

I have a little bit of a pop due to the specific filter I currently have on there.  It did not seal as good as the K&N will, no vacuum leaks, and overall runs great.

In the mean time, I left you with some parting shots of my bike and the install.

Don't mind the haze... can we say exhaust fumes...

The outer flange on this kit is 2 3/16 inches... makes it hard to find a filter,
but K&N has several that will fit this carb directly.

Temporary $8 filter till my new K&N comes in.  I adapted it to fit.
Oh yeah, Hard Krome Big Straights were the second mod I did to this bike.

One of the older mods on this bike the Jardine Oil Relocation Kit.
You can also see where I routed the carbs two vaccuum hoses and the float overflow hose

Even my seat is semi-custom

Video of it running... crappy cell phone video, but it is running great