I am thinking of having the Carbs on my 1987 CBR100F syncronized.
But the carbs does not look like the ones in the servicing manual i have.

The servicing manual states that the vacuum ports is on the underside of the intake manifold. Mine seems to be on top and front of the carbs itself.
The servicing manual also states that No. 3 carb is the master an cannot be adjusted. There should be adjustments on the other carbs.

On mine i only find two adjustments. One between Carb #1 and #2 and the second one between #3 and #4 . The first one will balance #1 and #2, the second one will balance #3 and #4.

Is this correct?

Stein-R.
Norway

 

Just make sure all the throttle blades move in synchronization. If one is lagging, adjust it. On snowmobiles you just eyeball it, and it seems to work (did it on my tripple 900 and tripple 600). I'm pretty sure Carb Sync'ing is for idle quality.

 

The problem with the bike is that it runs rough below 3000 RPM.
I have adjusted the valves and replaced the spark plugs. I have a Morgan Carbtune Pro tool to syncronize the carbs.

I just wanted toconfirm that I have identified the correct Vacuum ports and adjustment screws.

Stein-R.
Norway

 

There are three adjustments, the third is in between carbs 2 and 3, it is a little further down than the other two and harder to see. You need to use the Sync tool that has four vacuum gauges. Start at one end and make all four readr within 1 or 2 ticks of each other. It will improve your idle quality and some of your low end performance problems, i.e. cruising below 3k rpm. I know it help mine a lot.

Also, if you have a Clymer manual, you may be seeing how to sync a Hurricane 600, which has plugs on the engine. The ports on top of the carbs are the ones you want. You may have to adjust the idle afterward then sync them again. You can do the sync with the tank on the prop rod if you want, also.

 

If the bike runs ruff below 3000, its probably the idle circuit on the carbs. Syncing will help in general, but it sounds more like a good carb cleaning( remove the needles, seats, sliders, everything you can unscrew, unplug and open.) Get some spray carb cleaner/degreaser. Start checking ports, emulsion tubes, seats, etc. Make sure that you blow the cleaner thru thecarbs in backwards so as to remove the junk. See if you have varnish in the bowels. Check thebowel height for fuel level. Definitely keep track of where everything goes. Reinstall parts to each carb. Check to make sure the diaphragm is not ripped. check for smooth operation. Pilot screw adjustment is in order next. Again, Check the book. Take pics. Ask the forum as there are a lot of guys who are great at this.
It sounds like a big job, but once you've done it a few times, it becomes easier.
imho jm .02$.

 

I think this has been asked, can you clean the cabies without removing them?

 

You can't clean themwithout removing them. At least not effectively. It's not that bad once you've done it a couple times.

 

Like honda502 says, there are three sync screws. Number 1 carb screw is between carbs 1 and 2, and number 4 carb screw is between carbs 3 and 4. The screws are exactly vertical. The screw for carb 3 is just to the left of carb 3, in line with the other two screws, but the screw angles toward the back of the bike about 30 degrees from vertical. With the tank hinged up, it's almost impossible to see.

 

Ok, I have now pulled the carbs off the bike and found the third sync screw. While the Carbs where out I dismantled, cleaned,reasambled and synced them. But I am still not satisfied with the idling and the sound/behavior of the engine below 3000 RPM. (I have not driven the bike yet)

I could not find any data for the settings of the "Starting Enrichment Valves" index 27-29 in the service manual. Anyone know how to install and adjust these?

Stein-R.
Norway

 

It is not the "Starting Enrichment Valves" index 27-29 I need adjustment data for. It seems that it is the pilot screws. It is located on the side of the Carbs just above the float chamber cover. It consist of a tapered screw/needle with a spring and a small washer. The float chamber cover, when istalled, is restricting adjustment of this needle to just under at turn due tothe shape of the head of the screw and a locking tab at the float Chamber.

Is it this screw that should be installed 3 turns out from seated iaw. the servicing manual?