I thought these bikes were supposed to idle at about 1100rpm anyway?

 

Mine was idling weird and wouldn't hardly idle at all until it was warmed up, I tried everything that everyone here has suggested so far.

Turned out that my valves were out of adjustment by about .001", it's amazing what such a small difference can make.

I had synced my carbs before that and it did help a little so that may be the issue, but if you go thru all other suggestions with no luck I'd definitely say adjust the valves.

There's a thread under the HOW TO section which makes the process simple, just remember to sync the carbs after adjusting the valves

 

Carb balance does not affect idle. The pilot screws affect the idle, balancing the carbs gets the bike running smooth in the higher rev ranges. The slides are down during idle and the motor runs off just the air flow past the pilot screws. First do a carb balance at say 3000rpm then set up the pilots. These are set by using an accurate digital rev counter. From the 2.5 turns out from seated adjust one out by a further 1/2 turn. If the idle speed increases turn the rest out 1/2 turn as well till the idle speed no longer increases. Now turn the idle speed back to 1000rpm at the idle adjuster. Now one at a time turn the screws in till the idle speed drops by 50 rpm, then turn it back out by 3/4 turn and leave it there. Repeat for remaining screws. Don't rush, let the motor have a moment to settle at each adjustment.If the idle is still lumpy check valve clearances, compression and voltage at the coils. Also ensure spark plugs are gapped properly and clean. Hope this helps.

 

Good point although when I put them on they looked fine , but you never know how they are sitting at the bottom as its hard to see .. but I will check this one ..thanks Sebastionbear .

 

I dissagree.

Carbs out of balance will affect the idle because all the carbs are not pulling the same amount of air so the idle is uneven and the fuel drawn will be different. ( fuel pulled through the jets is based on the vacuum in the carbs )

Even the book tells you to make sure the carbs are in balance BEFORE you do the pilot screw settings.

 

I have to say since I joined this site , I have to take my hat of to the help and support from fellow Cbr riders .... It just shows we are countries appart , but all have a common interest our Cbr's ..many thanks

 

As did I my friend

 

Pilot Needles , Carb Sync and to a much lessor extent crank balancer all contribute
to a nice smooth & consistent idle - imo, other factors to be included plugs & air filter.

 

So - with carbs out of synch - you are going to be able to see a 50rpm drop from an unstable tickover.

Have fun setting the pilot screws

 

The balance is Very important, but if the pilot circuit is not flowing properly, nothing else matters.
The pilot jet can clog in a second, sync, usually happens over time, just my,$.02
I have dealt with a clogged pilot jet/s at least 6 times in 3 years, one time bike ran fine one night, next morning, was clogged and ran like crap, but just as mentioned once past idle circuit, runs great. but soon as you back off to very little throttle opening rough again.