First plug chop after carb rebuild and adjustment

[Gs1000g]

Does it hit the wall then recover as the revs go higher or is it like that all the way past 8k?

Ir seems to hit the wall then recover

[azr]

Turning the mixture screws in will lean things, so you could try a 1/4 turn on each. But really you should vacuum synch the carbs first before you start playing around with things. I guess the first questions should be, what bike are we working with here? since you've already done a nice clean up on the carbs and will be vacuum synching why don't you check your valves while you're at it. As for the jets, I'm not sure what your bike has from stock as I'm not sure what bike we're talking about but if you have the stock exhaust and the only change is a K&N filter to replace the stock one I'm pretty sure you should be using stock jets. If someone has been replacing jets and such I wonder if they played around with your needle height? have you checked. There can be a few reasons for a stumble at 8'000, main jet, needle height and maybe a couple of others but if it were my bike I'd get the carbs back to stock with that setup, check my valves, vacuum synch the carbs and then take it for a ride and see what she feels like.

[Gs1000g]

It's the 1980 gs1000, the jetting was increased by the PO I don't know if he changed needle height or not, before I cleaned and rebuilt everything it would pull as far as I wanted to rev it with the larger jets. I guess I need a Morgan car tune and to vacuum sync these bad boys

[hillsy]

Lift the needles a notch and see what happens. You're in the needle / main jet territory at that rev range (probably more the main jet).

[Gs1000g]

Don't get me wrong, I appreciate all the information but why would the bike run ok before the carb rebuild and have this hiccup afterwards? Is it because I fixed all the vacuum leaks? Thus changing The AF ratio

[hillsy]

Didn't you say it had bigger jets before?

If it ran well with them.........

[azr]

Possibly, that or the vacuum synch is out. Good to know the bike was running real well before you did the carb rebuild, at least you know the jetting change was ok.

[Gs1000g]

I should of mentioned that before, basically the events were I bought the bike almost two years ago. Rode the **** out of it. Then in the last month my mileage started suffering so I assumed it was a carb problem and I saw a gas leak from the fuel bowl turned O-ring issue.....carbs rebuilt new o rings in boots and carbs and gaskets, same jets and other set up is all the same then this issue started . All this time It actually was a bad spark plug from oreillys ���� the carbs needed cleaned and rebuilt anyways.... So now here we are

[hillsy]

So it's fixed? Good to hear.

For what it's worth it was a very strange symptom of hitting a wall and then coming good at that rpm range to be a carb issue. At 8k rpm the carbs are pretty much using the full main jet so there really is nothing that would change in the carbs for that symptom to occur.

[Gs1000g]

So it's fixed? Good to hear.

For what it's worth it was a very strange symptom of hitting a wall and then coming good at that rpm range to be a carb issue. At 8k rpm the carbs are pretty much using the full main jet so there really is nothing that would change in the carbs for that symptom to occur.

sorry for the misunderstanding it is not fixed those were the issues leading up to the hitting wall issue. After that I am currently trying to figure out that last issue

[hannibal]

The nice golden hue has went away on the pipes, I have checked mileage yet. I needed an ice cold beer after this fiasco today. What would cause the 8K stumbling?

What does the golden hue mean? My pipes have slowly gotten the golden tint in the past month. I feel like the bike is running hot, but not sure if that's related to the 100 degree weather. I'm scared that it's running a bit lean, which is causing it to run hot and turn the pipes gold. Are golden pipes a sign of running lean?

[Gs1000g]

What does the golden hue mean? My pipes have slowly gotten the golden tint in the past month. I feel like the bike is running hot, but not sure if that's related to the 100 degree weather. I'm scared that it's running a bit lean, which is causing it to run hot and turn the pipes gold. Are golden pipes a sign of running lean?

I believe the golden hue is a sign of richness, blue pipes are lean condition also some metal naturally dis colors but mine were gold

[jprice90]

Got it all cleaned up and back together it's hard to tell but the pipes were golden and now it has slowly went away

What a beaut, I have an 850, Identical. is this consider Cosmic Blue?

[AMK]

I believe the golden hue is a sign of richness, blue pipes are lean condition also some metal naturally dis colors but mine were gold

Gold (or straw) is the condition of hot metal, blue comes next then purple. It's progressive.

[hillsy]

sorry for the misunderstanding it is not fixed those were the issues leading up to the hitting wall issue. After that I am currently trying to figure out that last issue

OK - still the same resolution I think. You should be checking your ignition system.

It doesn't sound like a carb issue at the rpm range, however, raising the needles is free and worth a try.