Sputtering under hard acceleration

[DavidT]

My bike will occasionally sputter when I accelerate hard from a standing start. It will sputter, cough a bit and then catch and take off. It has been very warm here lately, well over a hundred, but it has happended once when the temps were only in the 90's.
Any ideas?

[CycleRob]

What bike? Single or dual spark? Does it "clear out" and run OK after the initial standing start sputter and go?

--Sounds like bad/fouled sparkplug(s).

--Also remotely possible it can be vapor lock (fuel boiling to air vapor in fuel rail and/or injector body) which gets blown thru when you blast off. It's more likely if your bike is black and has set in the sun.

[DavidT]

I have an R1150R single spark. It coughs a bit then takes off and runs great. It only does it if you really get on it from a dead stop.
Thanks for the reply.

[gregor]

Never seen those kind of 'only' temperatures! But try new plugs and park in the shade.

[DavidT]

Thanks for all the help, the temps have cooled down a bit and the issue seems to have gone away, I think it was likely the heat. And yes, here in the Midwest, temps "only" in the 90's are pretty common! If you ever make it to the States, come on by, we have some beautiful rides here in the Ozarks.

[bigjnsa]

I've been fighting this issue for nearly a year so I'm curious what you did to fix it. And you're right, its ONLY under hard acceleration. For example in 6th gear at highway speed, 70-75mph, I goose it to get around slower traffic and I have to wait 2-3 seconds for it to "kick" in.

[DavidT]

I can't really say that I "fixed" it, but my issue only happens when the engine is warm and the weather is really hot.