Carb Sync question...
 

So I did a carb sync last weekend.
I used a home made manometer, and it worked great...idle only bounces now maybe 50rpm
My only question is...Since they wont sync perfectly at both idle and 4000 rpm...am I better off synching at idle, at 4000 rpm, or somewhere in-between?
Thanks,
Mike

Sync at idle. Just make sure your idle speed is right.

It should be good...I originally synched at ~1200rpm, then after adjusting the throttle screw on the rear carb, I had to raise the idle a little bit.
So I wound up finishing the sync at ~1100-1150rpm...which is usually where I keep it.

Sounds good. For what it's worth, some guys have mentioned problems with dying at idle if under 1200. I'm where you are currently at and haven't had a problem yet.

if your idle is too low, whaterver rpm that is, you will not get sufficient oil flow through your engine. You should set it to spec.

True true. That's why I just run 5w20. Plus it's easy to find for cheap!

I have read other posts about people having problems with their bikes dying at a lower idle setting, but I never had that problem since I got the bike 7 years ago.
Also, I would figure that 50-100 rpm shouldn't make that much of a difference as far as oil flow, but to be honest, I never really thought of that...so you bring up a good point, Resident.
I just always thought the bike sounded smoother and happier at 1100rpm.

Just a thought, you can get the oil light to go off by cranking the starter. Don't know what rpm that happens.

Was just kidding about the oil... before someone attacks me.

Well 1100 rpm is still in spec as the spec is 1200rpm +\- 100 rpm

Thanks for the info, Hawk...I hadn't had a chance to check the manual yet. I knew it was 1200, but I forgot about the +/- 100.

If it is truly set to 1100, I do not think that our tachs are that accurate down low. I tend to play it conservatively and would set it to 1200. That being said, I have not looked at mine in a while.

hey mike, what do you mean by," it won't sync perfectly"?

At idle, the fluid is level on both sides of the manometer.
When I go to 4000 rpm and hold it there, the fluid rises on 1 side.

I never tried that, but it would seem that if they're sync'd, that wouldn't happen. Maybe someone who knows will be able to comment.

just a thought, the two cylinders require different jetting for a reason, I imagine that the exhaust length has something to do with the scavenging effect, therefore the amount of vacuum that it pulls in the upper rpm. Set at idle, forget the rest.

I also used ATF, a 2x4, and about 15 or so feet of vinyl tubing.
I had the two sides within 1/4 inch at idle.
It definitely made an improvement over the previous setting.