Running rich

[3Phase]

Maybe the needles/seats were replaced with aftermarket parts and now the float heights are bogus. With those miniscule jets it should fusing piston and combustion chamber bits to the spark plugs, not rich, fluffy, carbon.

It looks like the floats are all set too low and making the fuel level in the bowls too high but with exactly three Sigma of error all the way across.

[motoman]

Brant his caliper looks like it is dead on at .905 inches which he confirms, and he is running #40 pilots, a size leaner than stock.

Nothing about that says he should be anywhere near the richness he has?

Bet me........have tested this scenario and confirmed it tis true. Pertaining to pilot circuit, works on same principal as a glass of water half full as opposed to full and using a straw. Velocity needed(blowing across top of straw) to pull water up through and out top of straw having a full glass of water is less and more constant. Same scenario using a half glass of water is it takes more velocity across top of straw...and when it does come out top of straw, it is then more than needed, and all at once........correct metering ability is significantly reduced. So, having given that as a comparison to easily understand, all carbs using a float bowl, including automotive carbs, whether they be downdraft, sidedraft or updraft all feed fuel on that same principal. Float settings/fuel bowl levels are both critical, more so in the motorcycle world than automotive world. One more thing, is whether it be automotive carbs or motorcycle carbs, the float setting specs. are sea-level determinations from manufacturer, so with automotive carbs, float setting specs. need to be 1/8th in. to 3/16ths in. lower than manufacturers specs.
Float setting specs. in motorcycle world need to be 1/4 to 1/2 a millimeter lower.
Also, pertaining to motorcycle float bowl fuel levels in bowls, 1mm of static float change equals 3mm of fuel level change. So, with that, multi carb bikes need spot-on settings in order for all carbs to produce same fuel/air mixture so all cyls. are doing as close as one can get it, the same amount of work.
So, hopefully things can move on for checking more if previous things were done correctly.

[bikerphil]

All I did was add in some baffles.

Have you tried running it without the baffles? There may be too much restriction.

[BLOWCLVL]

Have you tried running it without the baffles? There may be too much restriction.

No I have not. I will try that.

[motoman]

Here is a pic of what the mixture screw looks like on my carb. The o-ring is new and at the bottom, then the washer then the screw.

....backwards.....washer first then o-ring. Washer protects o-ring from being sliced from the step on the mixture screw. (could be cause with setting issue your having)

[BLOWCLVL]

....backwards.....washer first then o-ring. Washer protects o-ring from being sliced from the step on the mixture screw. (could be cause with setting issue your having)

Ok I will take them off. Place washer then oring then mixture screw.

[BLOWCLVL]

Ok I took it apart and this is how I have the mixture screws installed.
On the left is the o-ring which is what was in first in the hole, followed by the washer then the spring then the screw. Is this correct way?

[pete_s]

Before you beat yourself up anymore on this problem,

maybe

as the bike starts with no choke, it tells you that choke plungers rubber parts are rotted.

When they go, they give you similar problems which I had occur !

Also, replacement float needle and seat has a new retainer spring sometimes interfere with the brass seat. Usually it pees on the floor, floods after you start it (w/ vacuum shutoff) or turn the gas on.

I'll keep my fingers for you crossed as I have been working on a xs850 w Hitachi carbs running lean for 1 year.

[BLOWCLVL]

Before you beat yourself up anymore on this problem,

maybe

as the bike starts with no choke, it tells you that choke plungers rubber parts are rotted.

When they go, they give you similar problems which I had occur !

Also, replacement float needle and seat has a new retainer spring sometimes interfere with the brass seat. Usually it pees on the floor, floods after you start it (w/ vacuum shutoff) or turn the gas on.

I'll keep my fingers for you crossed as I have been working on a xs850 w Hitachi carbs running lean for 1 year.

I doesn't start with the choke period. If I choke it, it doesn't even fire. When it is running and I pull the choke it increases RPM drastically.

[3Phase]

I doesn't start with the choke period. If I choke it, it doesn't even fire. When it is running and I pull the choke it increases RPM drastically.

You had the mixture screw o-ring and washer in the correct order, they're fine. Since you got it, has this bike ever run mostly correctly?


The Enrichener has a problem, Pete's right, it shouldn't do that and the rubber may be bad or it could be a few other things.

If anyone has cracked open the carburetors before you got the bike, or even so much as looked at a rebuild kit online, have you checked the needle numbers on the slide needles? Held the slide diaphragms up to a strong light to look for holes? They were fine the first time I checked the carbs when I first got my XS but after a little while they had a bunch of holes.

What are the numbers on the Pilot Air jets in the intake bells? I think they supposed to be #180 jets AND the Pilot Air circuit has to be clean or it'll run rich.

[Bonz]

Bet me........have tested this scenario and confirmed it tis true. Pertaining to pilot circuit, works on same principal as a glass of water half full as opposed to full and using a straw. Velocity needed(blowing across top of straw) to pull water up through and out top of straw having a full glass of water is less and more constant. Same scenario using a half glass of water is it takes more velocity across top of straw...and when it does come out top of straw, it is then more than needed, and all at once........correct metering ability is significantly reduced. So, having given that as a comparison to easily understand, all carbs using a float bowl, including automotive carbs, whether they be downdraft, sidedraft or updraft all feed fuel on that same principal. Float settings/fuel bowl levels are both critical, more so in the motorcycle world than automotive world. One more thing, is whether it be automotive carbs or motorcycle carbs, the float setting specs. are sea-level determinations from manufacturer, so with automotive carbs, float setting specs. need to be 1/8th in. to 3/16ths in. lower than manufacturers specs.
Float setting specs. in motorcycle world need to be 1/4 to 1/2 a millimeter lower.
Also, pertaining to motorcycle float bowl fuel levels in bowls, 1mm of static float change equals 3mm of fuel level change. So, with that, multi carb bikes need spot-on settings in order for all carbs to produce same fuel/air mixture so all cyls. are doing as close as one can get it, the same amount of work.
So, hopefully things can move on for checking more if previous things were done correctly.

Everything is fine with what you are saying with the straw story Brant.

However he showed a specific measurement that was right on the money and you said it wasn't. He said he was running smaller pilots and you told him the problem was he was running too big of Pilots.

And yes the order in which you have the O-ring washer spring and screw is fine.

[BLOWCLVL]

Everything is fine with what you are saying with the straw story Brant.

However he showed a specific measurement that was right on the money and you said it wasn't. He said he was running smaller pilots and you told him the problem was he was running too big of Pilots.

And yes the order in which you have the O-ring washer spring and screw is fine.

No fighting gentleman lol I will disassemble once more for the 20th time lol and tell you all exactly what the numbers are on all my parts with pics.

[Bonz]

Ok I will take them off. Place washer then oring then mixture screw.

NO... Don't change it. O-ring, washer, spring, screw is correct.

[BLOWCLVL]

You had the mixture screw o-ring and washer in the correct order, they're fine. Since you got it, has this bike ever run mostly correctly?


The Enrichener has a problem, Pete's right, it shouldn't do that and the rubber may be bad or it could be a few other things.

If anyone has cracked open the carburetors before you got the bike, or even so much as looked at a rebuild kit online, have you checked the needle numbers on the slide needles? Held the slide diaphragms up to a strong light to look for holes? They were fine the first time I checked the carbs when I first got my XS but after a little while they had a bunch of holes.

What are the numbers on the Pilot Air jets in the intake bells? I think they supposed to be #180 jets AND the Pilot Air circuit has to be clean or it'll run rich.

It has run like this from day one. I will get all the numbers tomorrow when I take it apart again

[BLOWCLVL]

NO... Don't change it. O-ring, washer, spring, screw is correct.

Copy that.