Motorcycle Repair: Jetting CB1100RC


Question
QUESTION: Hi Jan,

I own 2 RC'S and an RD. I bought a Dynojet kit for an IIOOF believing it would work in the RC but it is incredably rich everywhere with black smoke - it runs cleanly when the tap is turned off and fuel gets low in the bowls but at anything above half full on the float bowl level setting we get black smoke and I don't believe such a low level setting would work out on the road with the bowls being too empty. Do you have any ideas? Also all 3 of the 1100r came with very different needles nozzles and jets so I can't find a baseline. Could you give me the range of stock jetting for RC and RD. Many thanks in anticipation.
Regards,
Craig.

ANSWER: 1100F is much different to the 1100R.  Main jet sizes range from 105 to 125.  On the RC and RD models all four mains were the same I believe, on the RB, the inner carb jets were different to the outer carbs.  The CB1100RC and RD are well set-up by the factory, no need for mods unless you are making mods to the exhaust or airbox setup.

Good luck,  Jan

---------- FOLLOW-UP ----------

QUESTION: Thank you Jan.

However all of the jets on the 3 bikes are different so clearly previous owners have fiddled with at least 2 of the bikes meaning that I dodn't know what the stock jet ranges were for any of the jets on the RC/RD.
Can you give me the jets size range of all ofthe jets, needle sizes and nozzle sizes for RC/RD so I can establish a baseline. None of the 3 bikes run well so can't use any one of them as a baseline. I am at sea level so would err on the richer side of the sizes.
Thanks Craig.

Answer
Since you don't know what you are starting with, you need to make sure the needles are stock.  I would start with 115 mains.  If the bike runs rich on lower throttle settings then check the others jets too.  Sounds like you really need to get some time on a dyno to get these dialled in, anything else is guesswork.

Jan