CBRF2 Carb tunning question
 

Hello everyone,

The time has come for me to tune the cbr that I got 3 years ago. After letting it sit all winter, I cleaned the carbs and the bike starts wonderfully. After about 5500 rpm it bogs as if its mixture is not right. I believe the carbs are out of sync and will attempt to sync them.

I wanted to ask for some help in regards to tunning a cbrf2. I believe its non-cali model, year 1994.

I have a motion sync pro and once I get everything connected it shouldn't be a problem, however, I cannot decide where to connect the vacuum hoses from the monometer. I looked around and cannot find a diagram that I need.
Also I need to know which of the carburetors is the main in order to sync the motionpro monometer itself. (I believe its the second one from the right, please assure me)

From what I see there are 4 vacuum plugs/caps on the top side of the carburators (one on the left, two are between carbs, and one on the right)
are those the ones I connect the vacuum lines from the motion pro?

Also i noticed 3 more vacuum caps/plugs front underneath the carburetor that are covering bolts. What are those?


Many thanks everyone ahead of time.
-Damir :icon_confused:

Do you see the port where your petcock vacuum is hooked up to the engine? That is where the Sync tool connects to. Each cylinder has its own vacuum port. I cant remember which carb is the main sync to carb, I think is #3. Not exactly sure what you're speaking of "3 more vacuum caps/plugs covering bolts", but there would be 3 more plus the one that runs to the petcock. The sync tool connect to the engine, not the carbs.

Many thanks for your help, hopefully this sunday I can get it tuned and upload some pictures.

I'll look in my service manual and see for sure which carb is the main "sync to carb" and let you know. If someone else doesnt chime in first.

Just looked.......#2 carb is the base carb that the other 3 are sync to & #2 has no sync adjustment. You're very welcome.

when you say carb #2 i assume thats the one from the right (me sitting on the bike), to where throttle cable connects correct? my question is where to plug in the vacuum hoses exactly. please review this image and verify if I am correct.
http://ibb.co/ewLBhv
http://ibb.co/m5eF9a

the red circles on the picture are where the vacuum plug are located which i remove to tune them? or are the ports somewhere underneath?
Please pardon for my lack of knowledge, only reason I've posted is because everyone i've asked in person hasn't been able to help.

http://ibb.co/m5eF9a
http://ibb.co/ewLBhv

Also sorry if the pictures dont work I attached the links which i used imgbb.com to temporarily store.

I also wanted to thank you frank for explaining me this

First of all........you're welcome. 2nd of all.....NO, what you have circled in red is not vacuum plugs. Do you remember when you took your fuel tank off? There would've/should've been 2 rubber hoses coming from you petcock......one big one going to the carbs (fuel line) and one little one going to the #1 vacuum port on the engine, NOT THE CARBS, THE ENGINE. The vacuum port that makes your petcock function is what you hook the sync tool to, its #1, then there is another one on the next one over, its #2, its plugged, then another one, its should be plugged also, its #3, and finally over one more is #4, should also be plugged. You'll have to pull those plugs off and screw in threaded adapters that would allow the sync tool the connect. If they're not plugged they might have a small bolt in place instead of a plug. Anyhow, when sitting on the bike the cylinder & carbs are Left to Right 1, 2, 3, 4. #1 is the clutch/gearshift side. #4 is the brake side. Not trying to sound like a dick but judging from the pic with red circles, maybe you should invest in a Clymer manual for the ole' F2. The manual will show you where to hook everything up and explain how to sync. I love my Clymer manual.

Hey Frank,

I just got one too and its freaking awesome, thanks for all your help and I really appreciate your advice. Ride safe.