Topic: CB500 Idle Screw Modification Question

[brianj]

I'm in the process of rebuilding the carbs on my 73 CB500 and I ran across the Honda Chopper article where they show how to plug the hole in aftermarket carb kit idle screws:

hondachopper.com/garage/carb_info/idle_screw_mod/idle_screw_mod.html

It's supposed to help with idle/low rpm adjustments in bikes with free flowing intake/exhaust.  Since I'm running pods (I know...) and 4-2 with minimal baffles, I'm thinking this might be a decent idea for me.  However, I'm wondering if anyone with a CB500 has tried this before...  Does anyone have an opinion on why the hole really there in the first place and weather or not getting rid of it might be a bad idea?

[brianj]

Nobody's tried this?

[dave500]

ive soldered them up before,its a kind off smog limiter so you cant adjust too rich,a bit like those limiter caps on late 70s-80s carby equiped cars idle mixture screws,any 500/550 ive had has always idled and had better of idle pull with the solid screws,,its easy to un-solder them if you think you have to,i think jb weld is a bit amateur.


i mustnt confuse you with member bryanj ?

[brianj]

Cool, I guess I'll give it a go then.  Solder sounds like a good alternative, do you just heat the idle screws with a solder gun and melt the solder into the holes?  Any pro tips?

Also, no relation to bryanj, just a funny coincidence... Although he must be a pretty cool guy.

[dave500]

bryanj knows part numbers out of his head i think,,just solder them up and wet and dry them to shape if need be.

[xsmooth69x]

bryanj knows part numbers out of his head i think,,just solder them up and wet and dry them to shape if need be.

wait what does that mean solder them up and we and dry them?

also should i do this to my 550? do u do it to urs?

[dave500]

wet and dry is that black fine sand paper,,you can use it wet and dry,its not a sudden horsepower thing xsmooth,itll let you run a richer idle if your bike needs it.

[xsmooth69x]

wet and dry is that black fine sand paper,,you can use it wet and dry,its not a sudden horsepower thing xsmooth,itll let you run a richer idle if your bike needs it.

ow u mean wet sand! ya i have some 2000 grit stuff its awesome

ya i dont think i need it my 75 cb550 runs rich already from what i understand

[dave500]

heres some soldered ones.

i have to work out how to zoom better for this small stuff!

[brianj]

Excellent.  Thanks dave500.  Sounds like I have my weekend project picked out.

[crazypj]

I guess I'm out of touch, never seen drilled pilot screw like those.
I would solder them upand not worry about ot

[xsmooth69x]

I guess I'm out of touch, never seen drilled pilot screw like those.
I would solder them upand not worry about ot

ya mine have holes in them

dave500 its really easy to take close pictures. u need to change ur camera setting me macro. it should look like a flower icon.

[dave500]

i tried it on flower power and got fuzz,,man.

i mustve been using the wrong flowers,,i got it now thanks xsmooth.

[Deltarider]

any 500/550 ive had has always idled and had better of idle pull with the solid screws

Can you remember how many turns you had them out before?

[dave500]

no,i dont even know how many they are out now.

[Deltarider]

The reason I asked, is this strange "two turns out" that American Honda advises in their 1977 booklet, whereas in the rest of the world it is 1 turn out.
I can't understand how a CB500 with its airscrews 2 turns out can ever accelerate (of idle pull) well.
But I'll do a "2 turns out test" myself shortly as I happen to have the needles in 4th position, to experiment. That position is also recommended by that same American Honda booklet. whereas standard position in Europe is 3rd for the CB500, 500K1-K2.

[xsmooth69x]

i tried it on flower power and got fuzz,,man.

i mustve been using the wrong flowers,,i got it now thanks xsmooth.

u didnt mix up the mountain and the flower did you lol jk

flower setting is ur macro usually and u have to hold down the shoot button a little so it auto focuses then press down hard to shooooot! 

but u got it so its all good. those screws look cool and u have so many parts!

[xsmooth69x]

The reason I asked, is this strange "two turns out" that American Honda advises in their 1977 booklet, whereas in the rest of the world it is 1 turn out.
I can't understand how a CB500 with its airscrews 2 turns out can ever accelerate (of idle pull) well.
But I'll do a "2 turns out test" myself shortly as I happen to have the needles in 4th position, to experiment. That position is also recommended by that same American Honda booklet. whereas standard position in Europe is 3rd for the CB500, 500K1-K2.

i do one and one half turn for my cb550

[crazypj]

but u got it so its all good. those screws look cool and u have so many parts!

 If you work on old bikes for a few years you accumulate a lot of bits and pieces

[Deltarider]

But I'll do a "2 turns out test" myself shortly as I happen to have the needles in 4th position, to experiment. That position is also recommended by that same American Honda booklet. whereas standard position in Europe is 3rd for the CB500, 500K1-K2.

I just did a testride. With 2 turns out, mine doesn't accelerate as fluidly as I'm used to and at a stop the rpms have difficulty coming down. So I can't understand how American Honda can recommend this. It's definitely to lean.   

[dave500]

you have that inlet restrictor on the air intake though delta?