bluing pipes

[Guest]

Just sync. carbs and tried to set mixture screws by fastest idle, haven't been riding much, but pipes are turning blue and darker. So I must be running to rich? Didn't have this much bluing till I tried to set things right! terrylee

[Rick65Cat]

Just sync. carbs and tried to set mixture screws by fastest idle, haven't been riding much, but pipes are turning blue and darker. So I must be running to rich? Didn't have this much bluing till I tried to set things right! terrylee

Turning bluer and darker means LEAN dude!! Turning bluer means you've leaned it out more.

[terrylee]

Thanks I was just reading some old threads and that's what I found out. Thanks for the info. guess I'll be turning the mix. screws out more. Righty lean, lefty rich, right? terrylee

[terrylee]

Just went and turned them out to 3 turns, had been at 2 1/2. Hope to ride tomorrow and see what happens. Should you cover them with some caulk or something once you're sure they are set right, just to be sure of no air leakage? terrylee

[Steve]

Righty lean, lefty rich, right? terrylee

What bike you working on?

Have to ask, because different carbs have different adjustments.

If you are working on the skunk, the screws on the bottom are fuel screws. Turning them out (left) will richen the pilot mixture.

The screws on the side are air screws. Turn them out (left) will lean the pilot mixture.

Neither one of them should be anywhere near three turns out.

Also keep in mind that it's more likely that it's the MAIN jet that is leaning it out to turn the pipes blue. How much larger are they than stock?

.

[terrylee]

Sorry, just my 80 850, so just one screw. terrylee

[terrylee]

So should I have the mixture screws out 3 turns or is this to much. I have the Mac 4-2 system with stock airbox and filter. I had a slight light bluing on the pipes before I sync. carbs. and tried to set mixture screws correctly. But now it's almost bluer than blue! So am I going to have to take carbs. apart and check main jet sizes? terrylee

[1_v8_merc]

Don't you have to re-jet sometimes when installing new exhaust systems and air pods?

A lot of people do exhaust and new filter setup, and have running problems, until re-jetting.

[ajgs550]

Plug check?

What do the plugs look like? I have an 78 GS550 with a MAC 4-1 exhuast and pod filters. Bike was super lean until re-jetting.

550 Stock settings:
Main 80
pilot 15

After mods
Main 100
pilot 17.5

I had to do a lot of adjustments with both fuel and air screws until I got nice brown plug results.

This may give you a ball park for your 850.

[Steve]

Sorry, just my 80 850, so just one screw. terrylee

OK

So should I have the mixture screws out 3 turns or is this to much. ... So am I going to have to take carbs. apart and check main jet sizes? terrylee

As I mentioned, the mixture screws will affect the PILOT circuit ONLY.
That will be fine if you just sit there idling or maybe run it up (gently) to about 1500 rpm in each gear.

If you ever plan on running that bike the way a motorcycle should be run, yes, you will have to change the main jets.
Might have to shim the needles, too.

Don't you have to re-jet sometimes when installing new exhaust systems and air pods?

Not just "sometimes", but virtually EVERY TIME.

.

[terrylee]

Ok, but I have stock airbox and filters. And since I didn't have this problem till after sync. and screw adj. I just thought that might have caused the problem. I've had the Mac system for two years. Guess I shouldn't ride much till I get this fiqured out? terrylee

[Rick65Cat]

Didn't '80 have CV carbs? If so, I'm unfamiliar with them. All I know is if after adjusting the pipes turn bluer, you better reverse your adjustments quick.
And the mains...aren't they for wide open throttle?

[Steve]

Didn't '80 have CV carbs? If so, I'm unfamiliar with them. All I know is if after adjusting the pipes turn bluer, you better reverse your adjustments quick.
And the mains...aren't they for wide open throttle?

Yes, the '80 had CV carbs.

Mains will be in partial use above 1/4 throttle, more so at 1/2 throttle, then will be the primary fuel source above that.

.

[terrylee]

80 850 w/ cv carbs.

Ok, tried to clean the blue off my pipes and readjust things till I can get larger main jets. So I turned air mix screws out to try to richen (that is right? out is richer, in is leaner or righty-leaner, lefty-richer) Don't have time to resync. today but will try to do in next couple of days. Also I know I have seen mention on here about holes in bottom of airbox and this not being a good thing. So I do have three small holes on left and right side of bottom of box. So I covered them with duct tape for now to see if this would help with the lean condition, should I have done that, or are these holes needed? I did seem to get rid of alot of the backfiring when let off throttle. I planning on taken it for a short ride later and see if anything is better. It looks as through #115 is oem for main jets, so should I go up to #120? I have the 4-2 Mac, but stock airbox and filter. terrylee

[terrylee]

still looking for some answers please

Just thought I try to repost my questions about my 81 850. Thanks so much! terrylee