GS PD surging

[PW Cymru]

Well not exactly surging but feels like it's fuel starvation at low throttle setting.

As soon as I roll off the throttle it starts what feels like surging as if it has intermittent fuel starvation.

The bowls were clean as were the bowl jets, no sign of dirt at all.

It starts fine, ticks over and runs well on moderate and high throttle settings.

It's just low throttle setting where it occurs.

I need to change both filter bowl gaskets as they've seen better days and the right appears to be leaking when on the side stand.

Any thoughts ?

 

[Rob Farmer]

Sounds like it's running weak Paul. Mines started doing a similar thing on low and medium throttle positions. Fitted my air/fuel meter this afternoon and It's going to 17/18:1 - top ends fine though. I'm going to lift the needle a notch and see what difference it makes.

Maybe it's the fuel

 

[litelfun]

Hallo ,
I have a set of 4 pot brembos with the spliter if you wanted to fit them both or I can sell you just one they bolt strieght on to the original fork leg 100% fiting no off set pads are licke new , one works ok on the original 13mm master cylinder but up grading to a 15 or 16mm is the best you can du ! if you have a early GS with the basic switch gear then fit a radie pump on their !!! WP or wilber springs and you have a totally diferent bicke

 

[Rob Farmer]

One hell of an upgrade if it fixes surging

 

[litelfun]

One hell of an upgrade if it fixes surging

ups dont no how my reply ended up heir

 

[PW Cymru]

Hallo ,
I have a set of 4 pot brembos with the spliter if you wanted to fit them both or I can sell you just one they bolt strieght on to the original fork leg 100% fiting no off set pads are licke new , one works ok on the original 13mm master cylinder but up grading to a 15 or 16mm is the best you can du ! if you have a early GS with the basic switch gear then fit a radie pump on their !!! WP or wilber springs and you have a totally diferent bicke

Thats just blown me away

 

[PW Cymru]

Sounds like it's running weak Paul. Mines started doing a similar thing on low and medium throttle positions. Fitted my air/fuel meter this afternoon and It's going to 17/18:1 - top ends fine though. I'm going to lift the needle a notch and see what difference it makes.

Maybe it's the fuel

Hi Rob,

There's a fresh tank of fuel in it but I did find a leaking float bowl gasket which may effect the fuel pick-up.

I've fitted a new pair of OEM gaskets so will try it tomorrow and check the plug colour at the same time.

 

[PW Cymru]

Took it for a run and its improved but the left cylinder is a bit rich and the right is about perfect.

Tried setting the mixture but the left carb doesn't react to adjustment much, the rise in rpm as you adjust is barely noticable.

I'll run the tank to empty and check the tap filters just to make sure there's no crap in there.

 

[Rob Farmer]

Paul, it may be worth taking the left mixture screw out to see if any goo comes out. Took mine out this morning and had some oil globules come out. My mixture now adjusts properly.

 

[PW Cymru]

Thanks Rob I'll try that, labour of love these things

 

[PW Cymru]

Sorted, turned out it was a tight choke cable on the left carb which was just holding the lever off it's closed position.