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Carb Sync

(click on pictures to enlarge)

If you find that your scooter is running badly and has bad throttle response and rideability, then a carb synchronization might be just the ticket.
It seems that Honda went out of their way to make this procedure a challenge. Though it's documented in the shop manual and in after market manuals (like the Haynes manual) there are some specifics that are left out.
Though not really a farkle, I included the carb sync instructions here until I get a maintenance section completed.
First, make sure that you have the proper tools. You will need a 5mm allen wrench, 4mm allen wrench, 10mm and 8mm socket and extension, a #2 phillips and a #2 phillips stubby (short) screwdriver. A #3 phillips screw drive, at least 6 inches long. Needle nose pliers, and a good work light. You may also need a slotted screw driver, hemostats (the longer the better)
Remove both the right side and left side lower fairings to get access to the bottom of the carbs and the intake manifold vacuum ports.

Remove the two bolts on the front of the tank and raise the tank. To gain access to the carb sync adjuster screws it will be necessary to also remove the tank prop bar from the valve cover. So secure the tank with a rope or some strap to keep it up and out of the way.

To gain access to the sync screws on the number 1 and number 4 carbs, remove the starter circuit slider from the top of the carbs. There are two screws and the cable slides out of it's notch. Be careful to save the washers (plastic) slider washers (plastic) and the little spring attached to the left side slider mount. These all can pop off and get lost down in the engine very easily!


Next, carefully pry off the hose off the number on intake. This hose runs up to the petcock to provide vacuum to actuate the plunger in the petcock to allow fuel to flow to the carb bowls.

Carefully pry the rubber cap off the number 2 intake and the number 3 intake. Remove the allen screw from the number 4 intake. You will need to replace this with a screw-in port to attach your hose from your carb sync gauges. (I use a Morgan Carb Tune and they are included).

Attach all the hoses to the ports. You will need to apply a vacuum supply to the hose that you took off from the number 1 port, so fuel will be supplied to the carb. I use a Mity Vac for this.

Slide the hoses from your vacuum gauge onto the vacuum ports.

Start the bike and let it idle until fully warmed up. You might want to consider putting a fan in front of the engine to provide some airflow to aid in cooling. Avoid revving the engine with the gauges attached. Each type is different, so read the instruction for your gauges.  
After the engine is fully warm, adjust to idle to 1100 RPM via the idle speed adjuster screw by the number one carb. This only adjusts the number 3 carb, and since they are all linked via the linkage, each carb is adjusted along with the number three. After the idle is set you can start to adjust the screws. The goal is to have all the gauges level, or at the same reading. Most gauges are in Inches of Vacuum. It really doesn't matter on the CBR1000f  how many inches it is pulling, just as long as they are all the same.

There are only three idle adjustment screws. Number 1 carb, number 2 carb and number 4 carb. All of them are synced to the number 3 carb. The heads of the Number 1 and number screws are blue in color. The number 2 screw is a standard cadmium plated color, and is between the number two and number 3 carbs. The pictures show a screw driver in the position to adjust each screw. You can see where the screws are hiding by these pictures, It's difficult to see and impossible to photograph these screws.

Accessory Fuse holder

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To add additional electrical devices, you must somehow supply power and a fuse to the devices. People like to add things like heated grips, power outlets for GPS devices and radar detectors. Also heated clothing is popular in the northern areas for those of us that ride year round. There are several choices to do this, but I've found the most elegant solution is to add a aftermarket fuse box. There are several to choose from, but space is a consideration on the CBR. One popular choice is the Blue Sea, which is a marine application. Well built and functional, but fairly large. I found that there is no space under the dash for this unit, and the only place to mount it without doing some major cutting and such, is under the tail. For me, this was not a good choice. I have a Givi top case that would have to be removed to remove the tail piece to access the fuses. Or I would have to leave the wires long and fish the block out from under the tail. In reality, one would probably never blow a fuse, but Murphy's law states that if you do, it will be pissing out rain on a dark cold night a million miles from nowhere. Murphy and I are good friends, so I went a different route, and mounted a smaller fuse block under the dash. Which is accessible by removing just the lower right dash panel. Takes maybe 30 seconds to do.
I used this BUSE brand holder instead. It's much smaller and fits under the CBR dash.


Blue Sea Fuse box. Nice unit, but really hard to fit it on the CBR. Larger bikes like an ST or FJR it fits great!

 I also had to use a Ground block since this unit doesn't have any provision for grounding the circuit.

I also powered the fuse block off of a 30 amp Bosch relay which is powered by the rear tail lights. In other words, it is only on when the keyed ignition is on. No more draining the battery because you forgot to turn off your heated grips, or left the radar detector on all night. Actually I used two relays. One is strictly for the Magnum Blaster horns, described below.
This also has the added benefit of not running what ever current draw that the accessory has, through a switch. The accessory gets a full 12V straight from the battery. The accessories switch simply turns the relay on or off. Or in this case, it gets the power from the fuse lock.
I mounted the fuse block to a piece of aluminum with tie wraps and then tie wrapped mount to the front fairing stanchion. I mounted the grounding block to the stanchion right above the fuse block with tie wraps as well. They are both accessible simply by taking off the the lower right dash panel. Very simple.

The relays I mounted on the front cross bar, again each with a tie wrap. The one one the left in the picture is for the fuse block and the other for the horns. I ran a single 12 GA wire from the tail lights up to power the relay to the fuse block. I'm sure that there are wires under the dash that could be used for the switched power. The front running lights aren't a good choice, because they are a two wire system and when the turn signal is turned on, they power on and and off.

I also mounted two Powerlet style (BMW type) power sockets on the upper dash panels. One is for my GPS and uses a 2 amp fuse, the other is for another accessory such as a radar detector. Which I so desperately need. It's less expensive in the long run then speeding tickets and increased insurance rates. I have my eye on the Valentine V1. 8-)
One picture shows the two Sockets, one on each side and the other picture shows the underside of the left socket. I simply drilled the hole using a Unibit, which works brilliantly for drilling plastic to the perfect size.





Garmin Quest 2 GPS and Ram mount

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I use a Garmin Quest 2 GPS unit to help me route and find new roads. This is a nice little unit that comes with all of North America pre-loaded. It rests in a Garmin motorcycle mount. It features a audio plug so if you use some sort of mixer, like an Autocom or Starcom1 you can plug in and get voice directions. It works very well.

I used a Ram mount, part number GRA1BJ, available from Cycoactive, here in Seattle. Cycoactive is the North American Tourtech distributor. If you are into Adventure touring, you are familiar with Tourtech. On top of that is the 3.5 inch ram arm (part number GRANA) and then a round adapter plate (part number GRAB) to connect it to the Garmin MC mount. The Garmin mount has a neat little locking feature that prevents the unit from jumping out of the mount if you go over some rough road.
And it's powered from the switched fuse box via a Powerlet socket and 90 degree plug. I put a 2 amp fuse in the fuse box to protect it.

Magnum Blast Horns

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The horn on the CBR is wimpy to say the least. I really don't know why motorcycle manufactures use such little horns because they are an important safety device. This is the second bike I've done this mod to and it's probably the best $50 or so you could spend. These horns are SERIOUSLY loud! 138db each! Think two 1972 Buick Roadmasters in stereo. They will get the attention of any cell phone yakking soccermom that needs to be blasted back into reality.  
They are made a company called Carrand, in Italy. They might be the same as the Fiam's but I don't know for sure. I use two, one high note and one low note. I think it's important to do this so they combine into one serious tone that really wakes the dead. The picture shows the package and the part numbers for each. (Picture stolen from FJRtech.com. Thanks warchild!)

Wiring is simple enough. This diagram shows how to hook them up using a 12V 30 amp Bosch type relay (Picture stolen from FJRtech.com. Thanks warchild!). I wouldn't consider doing this mod without a relay. There is too much current going through the copper horn switch, and you run the risk of melting the contacts together and having the horns stay on after you release the button! Plus they really need the full 12V to get maximum effect. The other picture shows the two relays mounted under the gauges on the cross bar. The one on the right in the picture is for the horns, and the one on the left supplies power to the fuse block
I mounted the right side to the stock horn mount right above the radiator. I used the supplied brackets and nuts. The Left side I used the upper radiator mount and the upper fairing stanchion to keep it away from the forks at full steering lock. The right side required about a 1/2 inch of material be trimmed from the inner fairing for clearance. I simply used my Dremel tool to cut it away. The left side didn't require any trimming. I used a tie wrap on each one just to keep them from vibrating on rough roads.

Heated Grips

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In the winter time it gets pretty cool up here in the Pacific Northwest, so instead of waiting for winter to kick in I decided to install some heated grips on what turned out to be the hottest day of the year so far. A simmering 97F! Oh well... they will be much appreciated come winter time.


I Used the Symtec brand from California Sport Touring. They come with either a round rocker or a toggle switch. Another choice is the Dual Star brand, which is the exact same thing, or Hot Grips which are full grips. As you can see these are just the elements.
Alternately you can use a Heat-Troller for infinite adjustment. I've used the Heat-Troller  on other bikes and have found that I use only two settings. Full high or about half. So for this installation I decide to just use the round rocker instead
I mounted it on the lower left dash panel where the fuse access is .
The elements have super adhesive that sticks well to the bars. I used a length of heat shrink tubing on the metal clutch side under the element to keep the aluminum from acting like a heat sink. The clutch side does have a few extra elements to counter act this, but in the past I have found the throttle side is always warmer. I simply slid the grips over and glued them in place making sure that there is room for the wires to move and the throttle returns with out binding. Wiring is easy, and I ran it off a 5 amp fuse on my fuse block, so when the key is off, the grips will power off as well.

Volt Meter - Clock - Thermometer

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The lack of a clock has bothered me since I purchased the bike. I like to know what time it is when riding, to aid  in decisions like should I go exploring up that road, or just how late to work I'll be


I used this multiple function clock - voltmeter - thermometer unit from California Sporttouring. It's about 5" wide, 1" tall and about 3/4" deep. It's also back light for night time. It has a neat feature that will warn you of low battery voltage and ice. The low battery voltage is important on Hondas, because of the legendary  stator - rectifier problems. Now I'll now if for some reason the charging system is dying.
I mounted it right above the stock information (idiot) lights with a aluminum bracket. The bracket is stuck to the dash with strong double back tape (the kind that holds on automotive body side molding) and the voltmeter is attached to the bracket with Velcro, so if I need to remove the dash panel it will be simple. The wiring is simple. One constant hot 12+ , one 12+ switched and one ground. The constant hot I split off one of the relay feeds, the switched goes to the fused block and is protected with a 5 amp fuse. The ground goes to the ground block. The unit feature inside and outside temperature. The sensor for inside is on the unit, and is subject to direct sun on a bike.  It also has a long wire with and probe, which I ran to the tail section and mounted it with a tie wrap under the tail section to the license plate wire. Hidden from the direct sun and not subjected to the heat of the bike itself it give a good accurate temperature.


Stray Cat © 2009

Graphic Design by Max and Dixie

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