Problems with 800 BB + SLP twins

I would say your a little big on your jets, on mine 2000 RMK 800 with SLP twins,was in the 440 range at home. 2200 feet.

Yeah, it doesn't sound very good.

Are you running the 2002 needles as well? If so, that sure seems awfully lean. I think SLPs recommendations for the 02 800 with twins was in the 600 range or so at your elevation.

Is the only change you made going to the twins or did you make other changes at the same time?

You checked the water temp sensor?

sled_guy

That's 8*C, right? So 46*F at 1300' elevation. I ran my BB800 with race twins at much higher altitude, 9,000'+ but much colder temps with 330, 320, or 310 mains and 04' needles. Took a quick rip around the yard in Minnesota at 850 feet and 15*F with that jetting (310s at the time) and it ran fine for the short throttle blips I gave it. I suspect you're too rich especially at that warm of temperature, but what needles are you using?

Like Sled_Guy asked, was the only change from single pipe to twins?

Have you taken a look at the plugs? Wet/black? Or dry/white?

Are you running the factory heads or SLP domes? Any race gas? My 800 would deto at low altitude without race gas mixed in, sometimes it would even deto around 9'k when I had the factory head with 91 octane fuel.

What e-clip are the needles on? Doesn't sound like you opened it up in that video, so may have just been on the needle circuit instead of main.

that sled...

is only running on one cyl. way fat, maybe a piece of crap in one of the needle valves? Needles way off, jetting way fat? Bad plug?...