WOT stumble

[daves86vmax]

Help please,My 86 seems to be running fine under normal use but if I take off from a dead stop and really crank the throttle open it stumbles an acts like its not getting enough fuel to it.i drilled my brass plugs out and have been tweeting them(since this condition started)but it doesn't make it go away although it does make it different.i did the shotgun and peashooter to fix it but it still does it.should I repeat them or is something plugged inside the carb?thanks

 

[jfeagins]

1986 AND YOU JUST NOW REMOVED THE BRASS PLUGS COVERING THE A/F MIXTURE SCREWS??? Wow, that's gotta be a record.

If it runs well under low load, and at normal operating speeds, but only starts to stumble after having been WOT for a ways, I'd guess you may be running low on fuel in the fuel bowls...and no amount of shotgun or peashooter routine will help most likely. Then I vote check your fuel pump. Does it click a few times each time you turn on the key? If so, will it click several more times if you cycle the key back on immediately again and again? If so, that would indicate a problem in the pump.

If it begins stumbling immediately upon going WOT, maybe you have issues with worn out diaphrams, and this isn't immediately noticeable under light or normal load. And that won't be cured with any shotgun or peashooter routine either.

 

[daves86vmax]

Diaphragms look fine,2 are fairly new. When it started doing this is was immediate. Fine one minute and then bad soon after when I really got on it which is why I was thinking maybe I sucked some dirt in somewhere. Bikes ran fine since I got it in 08 so I didn't see a reason to drill the plugs out until now. Lol. It just may be a record. I'll check the pump like u mentioned. Ive never checked float levels so maybe I should try that also.

 

[jfeagins]

If it did it immediately, I would think it had nothing to do with fuel supply or levels in the carbs, and since your diaphrams are all OK, I would turn my attention towards crud, like you said, in the jets someplace. Maybe inspect your fuel filter to see if there's any crud showing up in there .

 

[daves86vmax]

By the way I fixed the stumble. I have the c.o.p. Kit on my bike instead of the factory coils/boots/wires.turns out one of my cops had been dug into by the coolant hose clamp and it was arcing out and must've ruined it. I replaced it(after slipping a piece of hose around it to protect it from the clamp)and bike runs fine again