Pilot screw?

[kiwi cowboy]

ok 83 cb900 is running rich and carboning the plugs.
in the workshop manual it says the pilot screw should be 1 1\2 turns out which they are but in the back it says that uk models [which i think mine is] it says the screws should be 1 7\8. out now would this affect the mixture when running at about 1\4 throttle it farts around but if given a handful it clears and takes off.

any coments cheers

[rudolph]

I have a 83 CB900 to, and I gave them 1 1/2 turns out seemed to work, the biggest problem is hard inlet manifold rubbers

[xwhatsit]

Well, most people will tell you that pilot screw only covers up to 1/8th of throttle. It's a little more complicated than that, as the effect is cumulative, but the gross effect it would be having at 1/4 throttle wouldn't be very much.

1/4 is needle territory. They get worn out after a while, which richens things up.

[rudolph]

you will be adjusting the mixture to compensate for air leeks and have a nightmare balancing the carbs to get the old bitch to run right

[kiwi cowboy]

Well, most people will tell you that pilot screw only covers up to 1/8th of throttle. It's a little more complicated than that, as the effect is cumulative, but the gross effect it would be having at 1/4 throttle wouldn't be very much.

1/4 is needle territory. They get worn out after a while, which richens things up.

ok so are needle jets and needles still avalible[if so were].

[kiwi cowboy]

you will be adjusting the mixture to compensate for air leeks and have a nightmare balancing the carbs to get the old bitch to run right

dont think its got any air leeks cos if it did it would be running lean not rich
is yours got the full farring great bike just need to keep it on 4 cylinders lol

[xwhatsit]

Most likely yes. Being a Honda of that era it's probably some Keihin CV thingie. Hopefully using standard jets/needles. Get them from any bike shop.

Jets are cheap as chips, $7 a jet or so, but I've heard needles can be surprisingly pricy for the silly bits of brass they are. However the needles being worn is just a suggestion, no idea of the facts. And another thing to think about is if it is the needles, then you can adjust the height they sit at (raising them to richen it, lowering them to lean it out).

[kiwi cowboy]

Most likely yes. Being a Honda of that era it's probably some Keihin CV thingie. Hopefully using standard jets/needles. Get them from any bike shop.

Jets are cheap as chips, $7 a jet or so, but I've heard needles can be surprisingly pricy for the silly bits of brass they are. However the needles being worn is just a suggestion, no idea of the facts. And another thing to think about is if it is the needles, then you can adjust the height they sit at (raising them to richen it, lowering them to lean it out).

yes they are keihin carbs and getting a price for new neddles and jets as the ones in it arnt adjustable as in no notches with a circlip which are the type your thinkin of maybe.
the chap at the bike shop also said if the air filter is dark stained even though ive blown it out the stain from road grime and stuf you cant get off buggers it so going to try a new air filter first.
can you get neddle kits that are adjustable for these carbs?
cheers

[rudolph]

dont think its got any air leeks cos if it did it would be running lean not rich
is yours got the full farring great bike just need to keep it on 4 cylinders lol

Mine did have the full faring but it got a custom make over and now nothing is sanded, my one had the pressed ally wheels with the round holes in the spokes not the state spokes.

I found that I would be running rich then go major leen etc, had no end of carb trouble, and it was all to do with hard inlet rubber manifolds

[FilthyLuka]

can you get neddle kits that are adjustable for these carbs?
cheers

www.factorypro.com

If anyone will have em they will. Drop them an email if the don't list the bike model, chances are there is an adjustable needle that will fit in that carb