Idle mixture screws and jerking

[Mr Toga]

Hi guys. Just took my bike out for its time around the block after installing a Dyna S, and cleaning the Carbs the correct way. During my ride, the bike would have a problem accelerating to ~3000 RPM. Once it hit 3000 it would take off. What could be causing this?

Another side note: Right now I have my Idle mixture screws all set out at 2 turns but its still running a tad rich. Should I keep screwing in or start looking other places to fix this problem. Thanks everyone.

[Nessism]

Two turns out is too lean for a 550T, try 3 turns and see how it runs. If the bike is rich at 2 turns, there is some other problem.

[Mr Toga]

Two turns out is too lean for a 550T, try 3 turns and see how it runs. If the bike is rich at 2 turns, there is some other problem.

Just tried 3 turns and it seems to be starting off a lot better. Now, I'm getting a lot of popping around 2500-3000 RPM. It's a hollow-sounding pop though. Would this be related to timing?

[Nessism]

Just tried 3 turns and it seems to be starting off a lot better. Now, I'm getting a lot of popping around 2500-3000 RPM. It's a hollow-sounding pop though. Would this be related to timing?

Timing is not adjustable and rarely an issue. Not sure what to suggest other than to make sure the airbox is properly sealed and that you don't have any vacuum leaks.

[chef1366]

I'm glad you didn't add 'off' to the end of your title.
Popping usually is a lean sign. Do as Ed said and seal you air box and intake to head o-rings.
If this doesn't help you'll need to shim you jet needle. Remove plastic spacer at the end of the needle and replace with the same heigth of washers and remove two to three of them. This raises the needle and richens it.

[Mr Toga]

I'm glad you didn't add 'off' to the end of your title.
Popping usually is a lean sign. Do as Ed said and seal you air box and intake to head o-rings.
If this doesn't help you'll need to shim you jet needle. Remove plastic spacer at the end of the needle and replace with the same heigth of washers and remove two to three of them. This raises the needle and richens it.

wouldn't removing washers lower the needle?

[Nessism]

wouldn't removing washers lower the needle?

There is a spring pushing up on the bottom of the needle so the height is adjusted by changing the shim stack on TOP of the clip, not under the clip like one might think. Take a look and you will understand. As chef Bill alludes, most GS's benefit from removing the plastic spacer on top of the clip and replacing with a washer stack which is roughly 1/2 the height of the spacer, which effectively raises the needle.

Good luck

[Mr Toga]

There is a spring pushing up on the bottom of the needle so the height is adjusted by changing the shim stack on TOP of the clip, not under the clip like one might think. Take a look and you will understand. As chef Bill alludes, most GS's benefit from removing the plastic spacer on top of the clip and replacing with a washer stack which is roughly 1/2 the height of the spacer, which effectively raises the needle.

Good luck

Okay. I took a look and it makes sense now. As far as the airbox is concerned, it looked okay besides this one small hole near the top right of the picture:



Is this supposed to be here or do I need to patch it? Also, there was fuel residue in the plastic piece connecting the carbs to the airbox. I assume this is not a good sign, but what can I do to fix it?

[rideOn]

Two turns out is too lean for a 550T, try 3 turns and see how it runs. If the bike is rich at 2 turns, there is some other problem.

so, turning out, or ccw, is richer? the mikuni on my thumper goes in for richer.

[tkent02]

Depends on the carb and on the screw, some are air screws, some are fuel screws, some are mixture screws.
The screws on Mikuni CV carbs are mixture screws, out is richer.

[rideOn]

mine is a bs32. still out to enrichen on the mixture screw?

[tkent02]

Yes .