97 FXDWG CV carb with new 45 pilot and 180 main. 2.5 turns out from seated on air/fuel mix screw. Arlen Ness Big sucker stage 2 air cleaner and VH short shots.

getting cough at 50%ish of opening my throttle. Not sure which variable to concentrate on 1st.

 

Update.

If I hold the throttle thru the coughing the bike eventually dies unless I let off the throttle.

research Ive done says it could be needle related. Ill try the washer method next. Good idea or could it be jet related?

 

Check the float and float needle, is this a sudden issue or a progressive issue? If it is sudden then maybe you have something in the tank causing the issue ( or not enough of something *cough* fuel *cough*) maybe there is an obstruction. Have you down anything to the carb, double-check your work, maybe you pinched the diaphragm. Definitely check the needle jet, it could have been reinstalled upside-down if you had the emulsion tube out when you did the main jet.

 

A sneeze or cough, is the sign of a lean condition.
Petcock, float level(doubt that), or perhaps a tear in the vacuum piston.
Scott

 

I am 99.99% sure it's not the Piston I triple checked it and was super careful reinstallig it. The needle doesnt sit fully if the emulsion is in upside down.

i thought it may have been an intake leak but I havent touched it, and I wasnt a similar symptom before. Unless I jarred the manifold putting thecarb or pipes on.

It only happens, and it happens the same point in the opening of throttle every time.

i havent taken it on the road because once I hit that point in that throttle where it starts coughing if I hold it there, or open it more, the engine dies.

I'm using the stock needle, no washers. I guess my next step is trying to raise the needle up or buying an aftermarket needle-which I've read that doesn't give you as much fuel as the washer option does.

 

Well, shimming doesn't really fix the issue as much as it will mask it, you will wind up with more fuel at the idle. I've had great luck with the CVP needle, you could check for intake leaks with the WD-40 trick. It's your bike but this is my 2¢. Good luck!

 

I think I figured it out. *I think.

-went to 46 pilot jet, up from 45. 175 to 180 main
-used 2 #4 flat washers to raise the jet needle.

didnt get a chance to ride since its a rainy mid 30° here in Pittsburgh but opened the throttle with no coughing, no backfire or anything abnormal.

🤘
-

 

If it liked the 46, it may still want more.
Scott