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idle erratic
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smearny
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Joined: Aug 13, 2009
Posts: 88
PostPosted: October 29, 2009, 2:36 pm    Post subject: idle erratic
my idle is not 100% stable.i didn't synchronise the carbs yet.is that the reason?!
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acbanks
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Joined: Mar 21, 2009
Posts: 72
Location: Raleigh, NC, USA
PostPosted: October 29, 2009, 4:40 pm    Post subject: Re: idle erratic
Does it hang at high rpm? Sputter and barely run?

I adjust my carbs like so. Crank the bike. Idle the left carb(so both carbs actually, since they're attached) way up. Unplug the right cylinder spark plug wire. Adjust the idle down until it barely runs. Turn the mixture screw on the left carb until it idle's fastest, drop the idle screw down some more, adjust mixture screw again and so on.

I have dual exhausts, so I try to feel an even, consistent PUTT-PUTT-PUTT-PUTT when I place my hand near the exhaust on that side.

Now plug the right plug wire back in and unplug the left. You'll have to adjust the synch screw between the carbs to change the idle speed of the right carb(or whatever it takes to keep the bike running) Repeat the mixture adjustment on this carb. Again you're looking for the best idle speed with no pops. It's subtle and tricky, should be around 2 turns out for stock carbs I think. Again, the goal is an even PUTT-PUTT-PUTT.

With both plug wires plugged back in you should now be able to idle it back down to 1200rpm with an even PUTT PUTT PUTT coming out of each exhaust side and no popping noises.

If you've done all this, you can then synch the carbs to get them perfect, but they should be close already. All of this assumes the carbs are clean with no air leaks.

Someone please correct me...I'm new to this as well.
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yamaman
Support Staff
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Joined: Jan 04, 2007
Posts: 1638
Location: Perth Western Australia
PostPosted: October 29, 2009, 4:53 pm    Post subject: Re: idle erratic
acbanks wrote:
Unplug the right cylinder spark plug wire.

This is ok if you run 2 single coils. If you run a dual output coil, disconnecting the coil can destroy them!

Keep 2 grounded spark plugs connected to the dual output coils at all times!
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smearny
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Joined: Aug 13, 2009
Posts: 88
PostPosted: October 30, 2009, 12:46 am    Post subject: Re: idle erratic
it doesn't sputter or hang.i wonder if it's the carb adjust or something else .somebody?!
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