Pilot Screws

[Dave M]

Hi again.

Which way do the pilot screws on the carbs on my 550 work?

Is it screw in to richen or screw out?

The manual isn't clear.

Thanks.

[dave400]

Dave,  I dont know bugger all about your 550 carbs but this may help....  It depends on the position of the screw on the carb body so if it

[SteveD CB500K0]

Dave, Dave is correct....

If they are on the engine side of the carb then turning in leans the mixture
If they are on the airbox side of the carbs then turning out leans the mixture

I have a set of 069As (CB550F) in my garage and the screw is on the airbox side.
I've also a set of 627Bs (CB500)  and they're the same.

[Dave M]

Cheers guys.

I get a bit of stuttering if I open the throttle from idle and also when opening it from a small throttle opening which makes me think it's a bit weak on the idle circuit.

I really need to remove them and clean them but that's a winter's night job.

I just want to ride it at the moment so I'll have a play and se what I can do.

[Dave M]

Bit of a result!

Mr Haynes says that the pilot screws should be 1 3/4 turns out + or - a 1/2 turn so, thinking it was running rich I screwed them in by 1/4 turn and tried it. Not happy.

Tried another 1/4 turn and even worse!

Backed them out again and then out  a further 1/4 turn. Better. Another 1/8 turn, better again so I've gone out the extra 1/2 turn and the difference is marked.

It idles fine and now it doesn't bog down when I set off and accelerates cleanly.

Still a bit hesitant when opening up from a small throttle on the move but again much better.

I'll try it for a while and might risk another 1/8th or a quarter. Can always turn it back.

Thanks for your help.

[Dave M]

Did a few miles today.     

Might try another 1/8 turn out.

[dave400]

Dave, I have standard exhaust air filter etc, the book say's 2 turns out + -  a 1/2 I have to say "that is   bollox", I'm still tweeking them after a year....good luck fella 

Dave 

[Dave M]

Thanks Dave.

I tried an extra eigth turn out and I think that was a bit too far so I've put them back to 2 1/4.

I'll run it for a while and see what it's like.

Miles better though!

[Dave M]

I've had all  the air screws out and given them a good clean and made sure they're all seating properly and am now running at 2 3/4 turns out which is + 1 turn on what Mr Haynes says.

It's running really well now with a very slight hesitation when opening up at around 4k revs in a high gear. However I'm happy and can live with that.

Just need to tweak the balance now.

I've done nearly 500 miles now and overall I'm very happy with the way it runs!